Fall 2013

Investi-g

A science journal for elementary school students

Animals and Ecosystems of the 

Southwestern United States
2 Investi-gator • http://www.scienceinvestigator.org 

Jessica Nickelsen, Co-Editor

Cradle of Forestry in America Interpretive Association

Babs McDonald, Co-Editor

Forest Service, U.S. Department of Agriculture

Elissa Riley, Education Consultant

Cradle of Forestry in America Interpretive Association

Julia Dobish, Education Consultant 

Cradle of Forestry in America Interpretive Association

Michelle Andrews, Evaluation

University of Georgia

Emily Melear-Daniels, Distribution

Cradle of Forestry in America Interpretive Association

Jean Szymanski, Southwestern Region Liaison

Forest Service, U.S. Department of Agriculture

Leslie Shaw, Design/Layout

www.leslieshawdesign.com

Stephanie Pfeiffer, Illustrator

University of Georgia

Lindsay Gnann, Cartographer

University of Georgia

Forest Service scientists highlighted in the journal:

Deborah Finch, Rocky Mountain Research Station

Paulette Ford, Rocky Mountain Research Station

Megan Friggens, Rocky Mountain Research Station

Hugo Magaña, Rocky Mountain Research Station

Carol Raish, Rocky Mountain Research Station

Other scientists highlighted in the journal:

Sharon Coe, Forest Service Contractor, University of 

Arizona

Kenneth Gage, Centers for Disease Control and Prevention

Darin Law, University of Arizona, Tucson

Alice McSweeney, Los Pinos Guest Ranch, New Mexico

Robert Parmenter, Valles Caldera National Preserve, U.S. 

Department of Agriculture

Max Smith, Forest Service Contractor, Wildlife Biology

Investi-gator

Forest Service

Washington, DC

Tom Tidwell, Chief

Jimmy L. Reaves, Deputy Chief, Research and 

Development

Jim Hubbard, Deputy Chief, State and Private Forestry

William Lange, Acting Staff Director, Science Quality 

Services

Kristen Nelson, Acting Staff Director, Conservation 

Education

Cal Joyner, Regional Forester, Southwestern Region

George S. Foster, Director, Rocky Mountain Research 

Station

Cradle of Forestry Interpretive Association

Carlton Murrey, Executive Director

Adam DeWitte, Director of Education

Jennifer Grantham, Chair

With thanks to

Project Learning Tree, http://www.plt.org

Produced by the Southwestern Region of the Forest Service (U.S. 

Department of Agriculture), the Rocky Mountain Research Station, 

Washington Office Forest Service Research and Development, 

Conservation Education, and the Cradle of Forestry in America 

Interpretive Association

 Animals and Ecosystems of the Southwestern United States Edition Number 3 • Fall 2013
Editorial Review Board

Comments from Pecos Elementary School, Pecos, New Mexico

Mr. Barela’s 5th grade homeroom class with assistance by Mrs. Diana Grabowsky

The most 

important thing I learned 

is that riparian forests 

are excellent habitats for 

wildlife.

I liked 

the pictures but 

they should be in color.

It needs more color 

in the words.

How 

did you guys come 

up with such a great 

story? I love those cute 

little hummingbirds!

I loved reading 

about the people 

and some of the tables 

and charts, but they 

could be more 

detailed.

Put more 

activities. Also put 

the animal’s diet and 

their skeletal system.

I learned that 

prairie dogs are 

important. So I am going 

to tell my family to try 

not to hurt prairie 

dogs.

Investi-gator is a 

good way to learn. 

Investi-gator • http://www.scienceinvestigator.org 3

The most 

important thing I 

learned was that 

animals are important 

and also scientists.
4 Investi-gator • http://www.scienceinvestigator.org 

Table of Contents

Editorial Review Board................................................................3

About Investi-gator......................................................................5

Who Are Scientists?.....................................................................6

Welcome to the Animals and Ecosystems of the Southwestern 

United States Edition of Investi-gator!........................................7

Features

That’s a Humdinger! 

Black-Chinned Hummingbird Nesting in Response 

to Forest Treatments ................................................10

By the Light of the Silvery Minnow: 

Can Young Minnows Be Taught About Their Natural Foods? .............28

Wild Ways: 

Assessing How Climate Change May Affect Certain Wildlife ...........40

Streaming Live: 

How Do Streams Affect How Well Trees Use Water? .......................53

Prairie Dog Days: 

How Fleas Transmit the Plague and its Effects 

on the Gunnison’s Prairie Dog ..........................................................70

The Lands of Time: 

Understanding Land Grants in New Mexico .....................................88

Southwestern United States Investi-gator Photo Challenge ......... 100

Southwestern United States Investi-gator Crossword Puzzle....... 101

Southwestern United States Investi-gator Map Activity .............. 102

National Education Standards....................................................... 105

What Is the U.S. Forest Service? .................................................. 107

What Is the Rocky Mountain Research Station? .......................... 107

What Is the Southwestern Region? ............................................... 107

What Is the Cradle of Forestry in 

America Interpretive Association?................................................ 107

Investi-gator Review Board.............................................Back Cover

Web Resources.................................................................Back Cover

Join Us in Being Green!

To reduce the amount of paper 

used to produce Investi-gator, the 

following sections are now available 

exclusively on the 

Investi-gator Web site, 

http://www.scienceinvestigator.org. 

These resources can be found with 

the Animals and Ecosystems in the 

Southwestern United States edition 

and on the “Educational Resources” 

pages: 

• Note to Educators

• Lesson Plan 

• Reflection Section Answer 

Guide

• Individual Article Education 

Standards Correlations

Photo by Larry Thompson.
Investi-gator • http://www.scienceinvestigator.org 5

About Investi-gator

Meet the Scientist

An introduction to the scientist or scientists 

who conducted the research.

Thinking About Science

A short introduction to something about the 

scientific process that is related to the research 

being presented.

Thinking About the Environment

A short introduction to something about the 

natural environment that is related to the 

research being presented.

Introduction

The part of the written scientific paper that 

introduces the scientific problem or question 

the scientists wanted to solve or answer.

Methods

The part of the written scientific paper that 

describes how the scientists collected and 

analyzed their data or information.

Each article is organized the same way and 

includes the following sections:

Findings

The part of the written scientific paper that 

describes what the scientists discovered.

Discussion

The part of the written scientific paper that 

summarizes the research and offers any new 

insights.

Reflection Sections

These are questions placed behind the 

Introduction, Methods, Findings, and 

Discussion sections. The purpose of the 

questions is to help students think about what 

they have read.

Glossary

Possible new terms found in the article. 

Glossary words are printed in bold in the 

article.

FACTivity

This is an activity that you can do in your 

classroom.

Investi-gator is the newest member of the 

Natural Inquirer family. Natural Inquirer, for 

middle school students, and Investi-gator, for 

upper elementary students, present science the 

way scientists most often share their research 

with each other. That process is the written 

scientific paper. 

Each Investi-gator article presents 

research conducted by Forest Service 

scientists and their cooperators. All of the 

research in Investi-gator is concerned with 

nature or with society’s relationship to 

nature.
6 Investi-gator • http://www.scienceinvestigator.org 

Scientists are people who collect and evaluate 

information about a wide range of topics. Some 

scientists study the natural environment. 

Who Are Scientists?

Be curious: 

Are you interested in learning?

Be open-minded:

Are you willing to listen to new 

ideas?

Question everything:

Do you think about 

what you read 

and observe?

Be careful:

Are you careful in everything 

that you do?

Be enthusiastic:

Are you excited about a particular 

topic?

To be a successful scientist, 

you must:










Investi-gator • http://www.scienceinvestigator.org 7

When most people think of the Southwestern 

United States, they think about deserts, 

deep canyons, cacti, and hot temperatures 

(figure 1). All those things help describe the 

Southwest. It is important to know, however, 

that the Southwest also has high mesas, 

mountains, trees, and cold temperatures. 

Some areas of these states even get 

snow, especially in the mountains. It 

is possible to play in the snow in the 

mountains and swim in an outdoor pool 

in a valley in the same day! 

The research in this journal was done in the 

Southwestern United States. The Forest Service 

identifies the Southwest as including the states 

of Arizona, New Mexico, and the western parts 

of Oklahoma and Texas (figure 2). 

The Southwest is an arid land with lots of 

sunshine, low humidity, and occasional high 

winds. These factors affect the way people live 

their lives there. Water is scarce. Sometimes 

people are only allowed to water their yards on 

certain days. Some people put small, decorative 

rocks in their yard instead of having grass that 

needs to be watered (figure 3). Little moisture 

and high winds are found in the forests and 

grasslands, so large wildfires are common 

(figure 4). These large wildfires change how the 

land looks. Wildfires also affect what kind of 

animals and plants live in an area. 

Welcome to the Animals and Ecosystems of the 

Southwestern United States Edition of Investi-gator!

Glossary words are in bold

and defined on page 9.

Figure 1. Many people think of cacti 

when they think of the Southwestern 

United States. Photo courtesy of the Forest 

Service Rocky Mountain Research Station 

Pathology Archive and http://bugwood.org.

Figure 2. The Forest Service identifies the 

Southwest as including the states of Arizona, 

New Mexico, and western parts of Oklahoma 

and Texas. The dark areas show the location 

of national forests.
8 Investi-gator • http://www.scienceinvestigator.org 

following different kinds of forest-related 

treatments. In “By the Light of the Silvery 

Minnow,” you will find out whether a small 

minnow can learn to find natural foods. Without 

success, this minnow population might one day 

disappear. You will learn how climate change 

might affect 30 different animal species in the 

article entitled, “Wild Ways.” Some of these 

species are already in danger of extinction. 

Southwestern people have lived close to the 

land for centuries. More archaeological sites 

are found in the Southwest than anywhere else 

in America (figure 5). The area was settled 

by Spanish, Mexican, Native American, and 

Anglo-American people. Each of these groups 

of people lived on and used the land differently 

(figure 6).

In this journal, you will learn many 

interesting facts about the Southwestern United 

States. In “That’s a Humdinger!” you will 

discover what happens to hummingbird nesting 

Figure 3. It is common to see 

decorative rocks in front yards of 

the Southwestern United States. 

Photo courtesy of Jean Szymanski.

Figure 4. Wildfires are common in 

the Southwestern United States. 

Photo courtesy of Kari Greer Photography, 

http://www.kariphotos.com.

Figure 5. Some early Southwestern peoples 

built and lived in cliff dwellings. Photo by Michelle 

Andrews.

Figure 6. Apache 

woman and papoose 

on the San Carlos 

Reservation in 1926. 

Photo by Stone and courtesy of the National 

Park Service Historic Photo Archive.
Investi-gator • http://www.scienceinvestigator.org 9

The Southwestern United States is 

a dry region. In “Streaming Live,” you 

will discover how well trees living in the 

Southwest use available water resources. 

“Prairie Dog Days” will introduce you to 

interesting facts about prairie dogs. You 

will learn how a small insect is causing 

big problems for a species of prairie dog. 

Finally, in “The Lands of Time,” you will 

find out how some people in New Mexico 

feel about land their ancestors owned in 

the past. 

The Southwestern United States is 

a special place. This Investi-gator will 

introduce you to a lot of fun facts about 

the animals, plants, and people living in 

the American Southwest.

Glossary

Anglo American (aŋ glō ə mer ə kən): A 

white American citizen of non-Hispanic 

descent.

archaeological (är kē ä lə jə kəl): Having 

to do with the scientific study of material 

remains of past human life and activities.

arid (a rəd): Excessively dry.

extinction (ik stiŋ(k) shən): The state or 

situation that results when something (such 

as a plant or animal species) has died out 

completely.

humidity (hyü mi də tē): The amount of 

moisture in the air.

mesa (mā sə): A flat-topped hill with steep 

sides.

population (pä pyə lā shən): A group of 

one or more species of organisms living in a 

particular area or habitat.

scarce (skers): Not plentiful.

species (spē shēz): A class of individuals 

having common attributes and designated by 

a common name.

wildfire (wī(-ə)ld fī(-ə)r): An uncontrolled 

fire that destroys a large area.

Accented syllables are in bold. Marks and definitions 

are from http://www.merriam-webster.com. 

Photos courtesy 

of the U.S. Forest 

Service.
10 Investi-gator • http://www.scienceinvestigator.org 

That’s a Humdinger! 

Black-Chinned Hummingbird 

Nesting in Response to 

Forest Treatments

Meet the Scientists!

Mr. Max Smith, wildlife biologist: My favorite science 

experience is going outside to discover where birds nest, what 

they eat, and what eats them. In the photo, I am bird-watching 

with my dog near Seattle, Washington. 

Dr. Deborah Finch, biologist: 

My favorite science experience is 

monitoring bird nests. I especially 

enjoy watching the adult birds build 

nests in trees and shrubs. I also like 

observing the nestlings grow and 

finally pop out from the nests and 

flutter to the ground.

biologist: This scientist studies living 

organisms and living systems.

wildlife biologist: This scientist studies 

animals living in the wild, including what 

they eat, their habitat, and how they 

interact with their environment.

What Kind of Scientist Did This Research?

Photo by Larry Thompson.
Investi-gator • http://www.scienceinvestigator.org 11

Figure 1. A riparian forest 

is productive because it 

is close to water. High soil 

quality in a riparian forest 

also makes the forest 

productive. Photo courtesy of 

Gila National Forest.

Thinking About 

the Environment

Riparian (rə per ē ən) forests are found 

along streams, rivers, and other waterways 

(figure 1). These forests are a transition area 

between water and upland areas (figure 2). 

Riparian forests are important because they 

help with flood control, water quality, and 

wildlife habitat. 

Forests help with flood control because 

a forest is like a sponge. Forests store water 

during floods just like a sponge stores water 

when you are washing dishes. Forests also help 

stop erosion along the banks of a river. The 

roots of trees and other plants help hold soil 

in place. These roots also help improve water 

quality by keeping extra soil, sediment, and 

pollution from getting into the water. 

Thinking 

about 

Science

Observation is an 

important skill for a scientist. 

Observation is the ability to watch something 

closely to gain information and details. In 

this study, the scientists frequently used their 

observation skills. The scientists observed 

hummingbirds and their nests over a 7-year 

period. 

Sometimes it was difficult for the scientists 

to see the whole nest. When the scientists could 

not see the nest, they made other observations 

to tell if the nest was doing well. For example, 

the scientists watched to see if birds were 

coming and going. The scientists also had 

several different people observe the nests to 

gather more data. 

The data the scientists gathered from these 

observations helped them to better understand 

hummingbirds and their nesting behavior. 

The next time you are outside, take 5 minutes 

to observe your surroundings. Write down 

three things that you noticed while you were 

observing that you never noticed before. Share 

your observations with your classmates.
12 Investi-gator • http://www.scienceinvestigator.org 

Riparian forests are also excellent 

habitats for wildlife. Forests provide food and 

shelter for many animals. These 

forests, for 

example, help shade 

waterways. The 

shade keeps the water 

cool and improves 

the aquatic habitat for 

certain animals. Trees 

and shrubs in the forests 

are also used as habitats 

by a variety of land 

animals. The scientists in 

this study were interested 

in the black-chinned 

hummingbird that makes 

its home in riparian forests 

(figure 3).

Figure 3. A 

black-chinned 

hummingbird 

and its nest.

Photo courtesy of 

Thinkstock.com.

Figure 2. The plants found in riparian areas often have 

characteristics of both the aquatic ecosystem and the upland 

areas because they are in this transition zone. Aquatic 

means that something is growing or living in or upon water. 

Illustration by Stephanie Pfeiffer.
Investi-gator • http://www.scienceinvestigator.org 13

Introduction

Many different types of birds live in riparian 

forests. In this study, the scientists were 

interested in black-chinned hummingbirds that 

live in riparian forests (figure 4). The scientists 

wanted to know if black-chinned hummingbirds 

were being affected by human changes to the 

forest.

Figure 4. The black-chinned 

hummingbird has a purple band on its 

neck. This is a male hummingbird. To 

see this photo in color, visit 

http://www.scienceinvestigator.org. 

Photo courtesy of Deborah Finch.

Did You Know?

All hummingbirds, including 

black-chinned hummingbirds, 

lay only two eggs at a time. 

Look at figure 3. How 

many baby hummingbirds 

do you see? Black-chinned 

hummingbird eggs are about 

the size of a coffee bean. The 

adults create nests that expand 

as the nestlings grow because 

the birds make their nests 

using spider silk and cocoon 

fiber. To find out more about 

black-chinned hummingbirds, 

visit http://www.allaboutbirds.

org/guide/black-chinned_

hummingbird/lifehistory.

Get 10 whole coffee beans. 

Measure and record the 

length of each bean. 

Calculate the average length 

of the 10 coffee beans. What 

would you say, on average, 

is the length of a blackchinned hummingbird egg?
14 Investi-gator • http://www.scienceinvestigator.org 

Humans make changes to forests for a 

variety of different reasons. These changes are 

called forest management. Sometimes forests 

are managed to reduce the risk of wildfire. 

When forests are managed to reduce the risk of 

wildfire, several treatments may be done. One 

of the treatments to reduce the risk of wildfire 

is to remove small trees and shrubs. Extra litter

and debris may also be removed. The scientists 

in this study examined this management method 

to see if it had an effect on hummingbirds. 

Forests are also managed to reduce the 

amount of invasive species. Invasive species 

include plants, animals, or organisms that are 

not native to where they live. Invasive species 

may cause harm to the environment, the 

economy, or human health. In this study, the 

scientists used herbicides to get rid of the 

invasive plants in the forest. The scientists 

also studied this method of management to 

see if it had an effect on hummingbirds.

What did the scientists want to 

find out in this study? 

Why do you think removing 

small trees, shrubs, and extra 

litter may help reduce the risk of 

wildfire?

Photo courtesy of Gila National Forest.
Investi-gator • http://www.scienceinvestigator.org 15

Methods

The scientists wanted to figure out if forest 

management methods affected black-chinned 

hummingbird nesting. To figure this out, the 

scientists examined three things. First, they 

looked at where in the forests the hummingbirds 

nested. This included identifying what species 

of trees and how high off of the ground the 

birds nested. The scientists studied how these 

areas changed following treatment. Then, the 

scientists looked at whether the nests survived. 

The scientists did their study in central New 

Mexico along the Rio Grande (figures 5a and 

b). The Rio Grande is a river that forms part of 

the United States border with Mexico. Blackchinned hummingbirds were prevalent in this 

area. The study took place between 2000 and 

Figures 5a and 5b. The 

Rio Grande flows out of 

the Rocky Mountains in 

Colorado to the Gulf of 

Mexico. 

Photo by Chuck Murphy and 

http://www.boywithcamera.com.

Mexico
No Treatment. 

(control plot)

Invasive shrubs 

cut & chipped. 

Herbicide applied 

twice to roots.

Invasive shrubs 

cut & chipped. 

Herbicide applied 

twice to roots. 

Native shrubs 

planted.

Invasive shrubs 

cut, piled, and 

burned. Herbicide 

applied twice to 

roots.

16 Investi-gator • http://www.scienceinvestigator.org 

Figure 6. Each block was 

divided into four plots. Illustration 

by Stephanie Pfeiffer.

If each of the 

three blocks 

were divided 

into four plots, 

how many total 

plots were 

established? 

Figure 7. The four treatments 

applied in the plots. 

2007. The scientists identified three land 

areas that they called blocks along the 

northern, middle, and southern reaches

of the Rio Grande.

Each block was divided into four 

plots (figure 6). In each set of four plots, 

one plot was randomly selected as a 

control plot. The control plots were 

areas that the scientists did not treat. The 

scientists compared the control plot to the 

other plots. This comparison enabled the 

scientists to learn whether the treatments 

or something else were affecting 

hummingbird nests. The other three plots 

were treated in three different ways.

In one plot, invasive shrubs and 

woody debris were cut down and chipped. 

Herbicide was then applied twice to the 

remaining roots of the invasive shrubs. In the 

second plot, the scientists repeated the first 

treatment. Then they planted native shrubs in 

the areas where they cut down the invasive 

shrubs. In the third plot, the invasive shrubs 

were cut, piled, and burned. Afterwards, 

herbicide was twice applied to the remaining 

roots of the plants that had been cut (figure 7).
Investi-gator • http://www.scienceinvestigator.org 17

What is chipping?

Big machines are used to turn trees and shrubs into small chips 

(figure 8). These chips are often used as a ground cover or are placed 

around trees to help hold moisture in the ground. 

Figure 8. Large 

chipping machines turn 

large trees into small 

chips of wood. Photo 

courtesy of the U.S. Forest 

Service. 

The scientists monitored all plots for the 

presence of black-chinned hummingbird nests 

and birds. The scientists monitored the areas 

between the beginning of May and the end of 

August each year. The location of each nest 

was recorded with a Global Positioning System 

(GPS) unit. The scientists also measured the 

height of the nest from ground level. They 

visited each nest every 3 to 5 days to make 

observations until nesting was complete. When 

possible, the scientists looked into the nests to 

see if the two eggs, and later the 

two tiny nestlings, were still in the 

nest. Nestlings are young birds that 

have not yet left the nest.

Once the nesting was complete, 

the scientists did two things. 

The scientists first measured and 

recorded the height of the tree or 

shrub. Then the scientists identified 

and recorded the condition (alive or 

dead) of the tree or shrub in which 

the nest was located. 

What is GPS?

A GPS is a navigation system. 

GPS stands for Global Positioning 

System. A GPS can tell the exact 

coordinates of where you are 

located on Earth. A GPS works 

by using satellites orbiting Earth 

to send information to GPS 

receivers. At any time, at least three 

satellites are able to send signals 

to any receiver on Earth. GPS was 

designed in 1973 by the United 

States military. The military 

designed GPS to help soldiers 

and military vehicles find their 

exact location anywhere in 

the world. Today, GPS units 

are used in a wide variety 

of ways. Often, cell phones 

have GPS receivers and 

you may even have a GPS 

device in your car that tells 

you directions!
18 Investi-gator • http://www.scienceinvestigator.org 

Why do you think the 

scientists monitored 

hummingbird nesting 

sometime between the 

beginning of May and 

the end of August every 

year? 

Why do you think the 

scientists visited the 

nests every 3 to 5 

days until nesting was 

complete?

Findings

The scientists found that black-chinned 

hummingbirds chose their nest areas differently 

in different plots. The hummingbirds made 

more nests in the cottonwood canopy after 

the area had been treated (figure 9). The nest 

location was also higher after an area had been 

treated. 

From 2000 to 2007, the scientists observed 

635 hummingbird nests. A majority of the nests 

(61 percent) survived. Of the 237 nests that did 

not survive, the cause of failure was not always 

clear. Some nests may have failed because 

of predators, weather, starvation, or fire. The 

scientists found, however, that nest survival 

rates were lower after treatments. 

Figure 9. The cottonwood canopy provided a 

nesting area for hummingbirds after treatments. 

This cottonwood canopy is located in New 

Mexico. Photo by Rod Replogle, Forest Service.

Female ruby-throated 

hummingbird.

Photo by Chuck Murphy and http://www.boywithcamera.com.
Investi-gator • http://www.scienceinvestigator.org 19

Why do you think it 

may have been hard to 

figure out why a nest 

failed?

In your own words, 

summarize the major 

findings from the study.

What percentage of the 

hummingbird nests represents 

a majority? Write the 

percentage in decimal form. 

Discussion

Before treatment, the riparian forest had a 

thick understory below a cottonwood canopy 

(figure 10). After treatment, the area looked 

like open woodlands with very few shrubs 

(figure 11). In response to these treatments, the 

hummingbirds moved their nesting areas to the 

cottonwood canopy. 

The scientists think that hummingbird nests 

located high in cottonwood trees are at greater 

risk from predators. The scientists think that the 

nests are easier for predators to see in the canopy 

as compared to nests that are located lower in 

thick shrubs and plants. Compare figures 9 and 10 

to see if you agree with the scientists.

The scientists also found evidence that nest 

survival was greater in the understory. Scientists 

suggest that after treatments, it is important 

to plant native shrubs and saplings so the 

hummingbirds have safer places to nest. Recall 

that one of the treatments included planting native 

shrubs. The scientists think that these shrubs 

did not have a chance to get large and dense

enough to provide protection. 

Figure 10. The understory is the area close to the 

ground underneath the tall trees. The understory is made 

up of small trees, shrubs, and other plants. Photo by Max 

Smith.
20 Investi-gator • http://www.scienceinvestigator.org 

Figure 11. An example of how 

the area looked after treatment. 

Photo by Max Smith.

Why do you think hummingbird nests may be safer in thick shrubs 

and plants?

Forest managers are often faced with decisions about how to 

best manage an area for multiple concerns. In this study, the area 

needed to be managed for fire, invasive species, and habitat for 

hummingbirds. Think of a time when you had to make a decision and 

there were competing interests. For example, you received $10 from 

your grandmother and you really wanted to buy a video game with it, 

but you also wanted to buy a present for your mom’s birthday. Think 

about how you made your decision. Write down two sentences about 

how you made your decision and compare it to the decisions these 

forest managers must make. Discuss with your class. 
Investi-gator • http://www.scienceinvestigator.org 21

Glossary

aquatic (ə kwä tik): Growing or living in or 

often found in water.

canopy (ka nə pē): The uppermost spreading 

branchy layer of a forest.

control (kən trōl): Part of an experiment that 

is not treated with something being tested. It 

serves as a comparison in the experiment. 

coordinate (kō ȯrd nət): Any of a set of 

numbers used to locate a point on a line or 

surface or in space. 

debris (də brē): The remains of something 

broken down or destroyed.

economy (ē kä nə mē): A system relating to 

the production, distribution, and consumption of 

goods and services. 

ecosystem (ē kō sis təm): Community of plants 

and animal species interacting with one another 

and with the nonliving environment. 

erosion (i rō zhən): The process or state of 

wearing or washing away. 

habitat (ha bə tat): The environment where a 

plant or animal naturally grows and lives.

herbicide ((h)ər bə sīd): Chemical substance 

used to destroy or stop plant growth. 

invasive (in vā siv): Tending to spread or 

infringe upon.

litter (li tər): The uppermost slightly decayed 

layer of organic matter on the forest floor. 

native (nā tiv): Living or growing naturally in 

a particular region.

prevalent (pre və lənt): Widespread.

productive (prə dək tiv): Having the quality 

or power of producing especially in abundance.

randomly (ran dəm lē): Selecting in such 

a way that each has an equal chance of being 

selected.

riparian (rə per ē ən): Areas along streams 

and rivers.

sediment (se də mənt): Material deposited by 

wind, water, or glacier. 

transition (tran zi shən): A changing from one 

state, stage, place, or subject to another.

understory (ən dər stȯr ē): The layer of plants 

and especially the trees and shrubs between the 

forest canopy and the ground cover.

Accented syllables are in bold. Marks and definitions 

are from http://www.merriam-webster.com. 

Adapted from Smith, D. Max; Finch, Deborah M.; Hawksworth, David L. 2009. Black-chinned 

hummingbird nest-site selection and nest survival in response to fuel reduction in a southwestern riparian 

forest. The Condor. 111(4): 641-652. http://www.fs.fed.us/rm/pubs_other/rmrs_2009_smith_d002.pdf

If you are a trained Project Learning Tree educator, 

you may use Activity 12: Invasive Species or 

Activity 22: Trees as Habitat.

The title “That’s a Humdinger!” is a phrase that refers to a striking 

or extraordinary person or thing. In this case, the extraordinary 

thing is the hummingbird. Learn more about hummingbirds at 

http://www.dgif.virginia.gov/habitat/hummingbirds.asp. 
22 Investi-gator • http://www.scienceinvestigator.org 

Materials 

• “That’s a Humdinger” article

• Copies of “Bird Identification Chart” on page 26

• Bird field guides (online editions or printed copies)

• Pencils

Optional: binoculars, digital camera

Time needed: Two class periods. 

The first day will be a classroom 

activity. The second day will be a 

classroom or field exercise.

The question 

you will answer in this 

FACTivity is: 

What species of birds 

are found living in my 

schoolyard? 

The scientists in the “That’s a Humdinger!” 

article studied black-chinned hummingbirds in 

New Mexico. They wanted to see if the birds’ 

nests were affected by forest management 

activities. The scientists observed the birds and 

their nests, and watched their behavior. Like the 

scientists, you will conduct a study to observe 

birds found in your schoolyard. 

Birds are important to ecosystems. They 

help control insect populations. Birds help 

scatter plant, tree, and flower seeds. Birds are 

prey for predators, and they serve an important 

role in the food web. Many people also enjoy 

birding, or bird-watching. Scientists who study 

birds are called ornithologists (or nə thä lə 

jists). In this FACTivity, you will act as an 

ornithologist while learning to identify birds 

seen in your schoolyard. 

FACTivity

As you learned in the “That’s a Humdinger!” 

article, a riparian forest is an area of forest 

between water and upland areas. Riparian 

forests provide habitat for wildlife, including 

many species of birds. Schoolyards can also 

provide habitat for wildlife. If your schoolyard 

has trees, it is an urban forest, a special type of 

forest. Urban forests are found throughout cities 

and other developed areas. Urban forests may 

have just a few trees, or they may have many 

trees.

For more information about 

urban forests, see the Natural 

Inquirer Urban Forest Edition at 

http://www.naturalinquirer.org. 
Investi-gator • http://www.scienceinvestigator.org 23

Day One: Learn to Identify Birds

1. If you haven’t previously done so, read the 

“That’s a Humdinger!” article. 

2. Make a list of birds that you think you might 

see in your schoolyard. If you live close to the 

school, it’s likely that you will see the same bird 

species at school that you see around your home. 

For each bird that you list, explain how you know what bird it is. For example, tell if 

it has red feathers or a thick beak. You might want to use a bird identification guide to 

give you some ideas.

3. Next, your teacher will divide you into small groups. Each group will be given a 

field guide. You may also use online resources such as Cornell University’s “All About 

Birds” Web site (http://allaboutbirds.org). The “Bird ID” section of the “All About 

Birds” Web site provides images and text that cover bird identification clues in detail. 

In your group, study the field guide and become familiar with ways to identify 

birds in the field. View images of birds that are common to your local area. This can be 

done by:

• Using BirdSleuth focus cards (order at http://www.birds.cornell.edu/birdsleuth).

• Viewing an online bird guide (http://www.allaboutbirds.org or http://www.

enature.com). 

• Looking at pictures of local birds (taken from magazines, posters, or the 

Internet) or looking at pictures in a field guide or textbook.

Photo by Chuck Murphy and http://www.boywithcamera.com .

Photo courtesy U.S. Fish and Wildlife Service.
24 Investi-gator • http://www.scienceinvestigator.org 

Day Two: Observe and 

Identify Birds in Your 

Schoolyard

1.You will observe birds seen 

at your school. Birds can be 

observed by looking out the 

classroom window or by going outside with your teacher. 

Your teacher will pass out the Bird Identification Chart to 

each student. If you have binoculars, they can be used to 

help you see birds close-up.

2. In your small group, discuss the Bird Identification Chart 

with your classmates. Work together to discuss identification 

features and ways to identify birds. Use the completed chart 

to help you fill out the Bird Identification Chart for one species 

of bird that you observe. Write down key identification 

features of a bird you see, such as “This bird has blue 

feathers and sits upright on a branch.” 

3. Work with your small group using field guides to determine if 

your identification is correct. 

4. As a class, discuss the birds you observed and the features 

used to identify them.

5. Once you have practiced observing birds from your 

classroom, go outside with the class (if you haven’t already) 

and observe birds in the schoolyard. Practice using a field 

guide to identify birds that you see. 

Photo by Chuck Murphy and http://www.boywithcamera.com. 

Photo courtesy of Gila National Forest.
Investi-gator • http://www.scienceinvestigator.org 25

FACTivity Extension:

Now that you’ve practiced observing birds, your class can conduct a 

Stationary Bird Count and submit the data online to the BirdSleuth 

database. For more information and instructions on how to complete this 

extension, view the “Birding FACTivity” on the Natural Inquirer Web 

site at http://www.naturalinquirer.org/Outdoor-v-102.html.

Name: 

Eastern Phoebe

Size: 

About the same size as a sparrow, about 7” 

from head to tail.

Sketch Shape: 

Plump bird with medium-long tail. Short, thin, 

black beak. 

Field Marks: 

Dark head that fades to lighter color on back. 

White throat.

Behavior(s): Flew from perch to catch an insect 

in the air. Bobbed up and down and from side 

to side when sitting on a branch.

Song(s) or call(s): Raspy “fee-bee” call and some 

soft chirps.

Color(s): Dark brownish-gray above, off-white 

below. Light patch of yellow on belly.

Habitats/Other comments: Perched on low 

branches; did not seem scared of humans.

This activity was adapted with permission from the Cornell Lab of Ornithology’s BirdSleuth curriculum. To order the complete 

curriculum set, visit http://www.birds.cornell.edu/birdsleuth/.

Sample Bird Identification Chart
26 Investi-gator • http://www.scienceinvestigator.org 

Name: Size: 

Sketch Shape: 

Field Marks: 

Behavior(s): 

Song(s) or call(s): 

Color(s): Habitats/Other comments: 

Bird Identification Chart
Investi-gator • http://www.scienceinvestigator.org 27

Cornell Lab of Ornithology- Black-chinned hummingbird

http://www.allaboutbirds.org/guide/Black-chinned_Hummingbird/id

Audubon Kids Page

http://www.audubon.org/educate/kids/

Tucson Bird and Wildlife Festival

http://www.tucsonaudubon.org/festival.html

Attracting Hummingbirds

http://www.hummingbirds.net/attract.html

Additional Web Resources

Photo Credits:

1, 3 and 4: Chuck Murphy and 

http://www.boywithcamera.com.

2: Photo by Dave Menke and courtesy of 

U.S. Fish and Wildlife Service.

5-7: James Holland.

1 Cardinal

2 Mountain

chickadee

3 Ruby-throated hummingbird (male)

4 Ruby-throated 

 hummingbird (female)

5 Broad-winged hawk

6 Osprey

7 Black-crowned

 night heron

Look at each of the bird photos. Write down 2 similarities and 

2 differences you see among the birds. Why do you think 

these birds have some different characteristics?
28 Investi-gator • http://www.scienceinvestigator.org 

Dr. Hugo Magaña,

fisheries biologist

My favorite science experiences are 

teaching about photosynthesis and studying 

food webs. In this photo, I was collecting 

algae from which I would later create pure 

diatom cultures. Diatoms are one-celled 

algae. I then created diatom pucks from those 

cultures. You will learn about diatoms and 

diatom pucks in this article!

Meet the 

Scientist!

Can Young Minnows Be Taught 

About Their Natural Foods?

fisheries biologist: This scientist studies fish living 

in the wild, including what they eat, their habitat, 

and how they interact with their environment. 

Of all the talents needed by scientists, one of the most surprising is creativity. To 

solve problems and answer questions, scientists need to think in new ways. Albert 

Einstein once said, “I am enough the artist to draw freely upon my imagination. 

Imagination is more important than knowledge.” Einstein meant that to discover 

new things, we must use our imagination and our creativity.

In this research, you will read about a creative way to study fish. The scientist 

in this study used his imagination and technology to learn something new about 

a small minnow that lives in the Rio Grande. The Rio Grande is a river in the 

Southwestern United States.

Thinking About Science

What Kind of Scientist Did This Research?
Investi-gator • http://www.scienceinvestigator.org 29

Thinking About 

the Environment

The Rio Grande is a long river. 

The Rio Grande’s headwaters are 

in Colorado. The river runs through 

Colorado and New Mexico. The 

river leaves New Mexico and forms 

part of the United States boundary 

with Mexico in Texas (figure 1). In 

the past, the Rio Grande was a wide, 

shallow, meandering river (figure 2). 

In the 1940s, people began to change 

the river. They created dams to 

control floods (figure 3). People also 

dug channels to divert water from the 

river to their agricultural fields. The 

Rio Grande is different today than it 

was before the 1940s. 

Figure 1. The Rio Grande flows 

from Colorado and eventually 

forms part of the United States 

boundary with Mexico.

Figure 2. Before the 1940s, the Rio 

Grande was a wide, shallow river with 

many bends. Photo by Chuck Murphy.

Figure 3. Dams were 

built on the Rio Grande to 

control floods. This is the 

Elephant Butte dam. Photo 

courtesy of the United States 

Bureau of Reclamation.

Mexico
30 Investi-gator • http://www.scienceinvestigator.org 

Because of the changes made to the 

Rio Grande since the 1940s, the river now 

provides a lower quality habitat for some 

fish and other aquatic animals. Some of the 

fish that thrived before the 1940s are not 

doing as well in the changed Rio Grande. 

One of these fish is the Rio Grande silvery 

minnow (Hybognathus amarus) (figure 4).

In the past, the silvery minnow was the 

most abundant fish in the river. Now, the 

silvery minnow is listed as endangered by 

the U.S. Fish and Wildlife Service. When a 

species is listed as endangered, it means its 

population may disappear in all or in many 

of the areas where it lives.

Figure 4. The Rio Grande silvery 

minnow is a small fish. An adult 

may reach 3.5 inches, or 8.89 

centimeters. Is this illustration 

of the silvery minnow life-sized? 

How do you know? Illustration by 

Stephanie Pfeiffer. Introduction

Many changes have occurred in the Rio Grande since the 1940s. (See 

“Thinking About the Environment.”) These changes created a river that is 

deeper and faster. This different habitat has created problems for the Rio 

Grande silvery minnow population. So few silvery minnows now live in 

the Rio Grande, the fish is in danger of becoming extinct.

Where Do Silvery Minnows Live and What Do They Eat?

Silvery minnows prefer slow-moving water. These minnows are found in 

eddies. These eddies are formed by debris in the water and in shallow pools. 

In the summer, silvery minnows stay in shallow water that is less than 20 

centimeters (7.9 inches) deep. In the winter, the minnows stay in water between 

31 and 40 centimeters (12.2-15.75 inches) deep. Silvery minnows prefer to 

swim near the river bottom. The minnows prefer to swim there because they 

feed near the river bottom. Silvery minnows are covered with taste buds all 

along their underside, head, and mouth. These taste buds allow silvery minnows 

to detect food even when they cannot see in slow-moving, turbid water. Look 

at the photo of Dr. Magaña on page 28. He is standing in turbid water. 

When water flow is slow, algae are the preferred food of the Rio Grande 

silvery minnow. Algae are aquatic plants that create their own food. Silvery 

minnows eat aquatic invertebrates during floods when the water is flowing 

quickly. Aquatic invertebrates are small animals, such as insects, crustaceans, 

mollusks, and worms, that live in water. Invertebrates do not have a backbone 

(figure 5). 
Investi-gator • http://www.scienceinvestigator.org 31

Figure 5. Invertebrates are animals without 

a backbone. Are humans invertebrates? 

How do you know? Is the silvery minnow an 

invertebrate? Illustration by Stephanie Pfeiffer.

To rebuild the population of Rio Grande 

silvery minnows, biologists raise the minnows 

in fish hatcheries (figures 6a and 6b). 

Biologists feed the minnows in the hatcheries 

with food that is made in factories (figure 

7). This food is unlike the minnows’ natural 

food. When the minnows are released into the 

Rio Grande, 95 percent of them starve or are 

eaten by other animals. Some scientists believe 

that the minnows starve because they do not 

recognize their natural food sources.

Before the 1940s, silvery 

minnows could be found in 

3,862 kilometers (2,400 

miles) of the Rio Grande. 

Today, silvery minnows are 

found in 280 kilometers (174 

miles) of the Rio Grande. 

Write the distance today 

compared with the distance 

in the 1940s as a fraction.

Extension: In what percentage 

of their past habitat are silvery 

minnows found today?

Figure 6a. Rainbow trout raised in a 

North Carolina fish hatchery. Photo by 

Babs McDonald. 

Figure 6b. Fish hatcheries do not 

provide a natural environment for young 

fish. Photo by Babs McDonald.
32 Investi-gator • http://www.scienceinvestigator.org 

The scientist in this study was interested 

in the natural diet of silvery minnows. Silvery 

minnows are mostly plant-eaters. Young silvery 

minnows eat algae. The type of algae they feed 

on is made up of diatoms. 

Figure 7. Emily Melear-Daniels feeds fish 

in a North Carolina fish hatchery. When 

fish are released into streams, they 

have to find their own food. 

Photo by Babs McDonald.

What are diatoms?

Diatoms are one-celled algae 

that live in colonies (figure 8). 

A diatom’s cell wall is made of 

silica. Silica is used to make glass. 

When the diatom dies, its interior 

decays, leaving the skeleton of silica 

behind. Scientists investigate these 

skeletons to discover clues about past 

environmental conditions.

Figure 8. Nitzschia palea is a species 

of diatom. This is an individual diatom. 

Individual diatoms cannot be seen 

without a microscope. Photo courtesy 

of Dr. Hugo Magaña.

The scientist thought that silvery minnows 

raised in fish hatcheries could be taught to 

recognize and eat natural food sources, such 

as diatoms. If silvery minnows could learn 

to recognize natural food sources while in 

hatcheries, fewer might die of starvation after 

their release into the Rio Grande. If fewer 

minnows die of starvation, the silvery minnow 

population might be saved from extinction.

The scientist wanted to answer this question: 

Can young silvery minnows be taught to 

recognize natural food sources such as diatoms?
Investi-gator • http://www.scienceinvestigator.org 33

State in your own words what problem the scientist was trying to solve. 

Use your imagination to brainstorm ways that young silvery minnows 

might be taught to recognize their natural food sources.

Methods

The scientist used eight aquaria. 

(Aquaria is the plural form of aquarium.) 

Each aquarium held 37.85 liters (10 

gallons) of water. Two of the aquaria were 

used for holding fish. Six of the aquaria 

were used for feeding trials. The scientist 

randomly selected young fish from the two 

aquaria. Then, the scientist placed 1 fish in 

each of the six aquaria until 10 fish were in 

each aquarium (figure 9). 

Figure 9. The scientist used aquaria to 

do his experiment. You may have similar 

aquaria in your classroom or at home. 

Photo courtesy of Dr. Hugo Magaña.
34 Investi-gator • http://www.scienceinvestigator.org 

The scientist grew diatom colonies in petri

dishes (figures 10 and 11). In this case, a colony 

is like a community consisting of a large number 

of tiny organisms. As if using a cookie cutter, the 

scientist used a cylinder to remove part of the 

diatom colony from the petri dish. The resulting 

piece of the diatom colony looked like a hockey 

puck. The scientist, therefore, called the diatom 

colony pieces “pucks.” 

The scientist placed 6 pucks each on 6 pieces 

of Plexiglass®. Each puck was the same distance 

apart. Each piece of Plexiglass® was placed into 

an aquarium holding the 10 young minnows. To 

observe the fish, the scientist videotaped each 

aquarium. The scientist could, therefore, view 

the video later and observe the fish (figure 12). 

The scientist timed the number of minutes it took 

young minnows to locate and sample diatoms 

from the pucks. This process was repeated six 

different times.

The scientist then waited between 5 and 17 

days. During this time, he fed the young minnows 

regular aquarium flake food. He then repeated the 

process used before with the pucks. The purpose 

of this experiment was to determine whether 

young minnows that had previous experience 

would quickly recognize their natural food.

Figure 10. The scientist grew diatom 

colonies in petri dishes. Photo courtesy of 

Dr. Hugo Magaña.

Figure 11. The scientist grew 

Nitzschia palea colonies from 

samples he collected in the Rio 

Grande. See Dr. Magaña’s photo 

on page 28. Photo courtesy of Dr. Hugo 

Magaña.
Investi-gator • http://www.scienceinvestigator.org 35

Figure 12. The scientist used 

video cameras to observe and 

record the feeding behavior of 

young minnows. The cameras were 

operated by Matt Julius, shown 

here. Photo courtesy of Dr. Hugo Magaña. 

Why did the scientist select 

the minnows randomly? 

What is one advantage of 

using a video camera to 

observe the minnows’ feeding 

behavior?

Figure 13. The minnows ate from 

the diatom pucks. Illustration by 

Stephanie Pfeiffer.

Findings

The scientist found that minnows not 

previously exposed to pucks took an average 

of 250 seconds to locate the pucks and sample 

the diatoms (figure 13). Minnows introduced 

previously to pucks took an average of 49 

seconds to begin feeding. Some of the minnows 

began eating from the pucks within 4 seconds.
36 Investi-gator • http://www.scienceinvestigator.org 

How many whole 

minutes are contained in 

250 seconds? 

How many minutes and 

seconds are in 250 

seconds?

Based on the findings, what 

conclusion would you reach 

about minnows’ previous 

experience with finding 

and sampling natural food 

sources? 

Do you think the timing 

difference between 

inexperienced and 

experienced minnows could 

be due to something other 

than previous experience? 

Why?

This study’s purpose was to discover if young 

silvery minnows can learn to quickly recognize 

and feed on natural foods. If the minnows can 

learn, they may have a better chance of survival 

after being released into the Rio Grande. Some 

silvery minnows learned to locate natural food 

after just 30 seconds. Days to weeks later, they 

remembered what they learned. They quickly 

located the natural food and began eating. 

The scientist observed that once the first 

minnow began eating, other minnows quickly 

joined. Another advantage of training minnows 

is that a trained minnow might be a role model 

for other minnows. If untrained minnows see 

a trained minnow sampling a natural food, the 

untrained minnows may also try the food. 

The scientist believes that silvery minnows 

hatched and raised in fish hatcheries can be 

taught to identify natural foods. This teaching 

may help prevent the silvery minnow population 

from becoming extinct.

Discussion
Investi-gator • http://www.scienceinvestigator.org 37

Glossary

Is it important to save the 

silvery minnow population 

from becoming extinct? 

Why? Is it important to save 

any species from becoming 

extinct? Why? 

The scientist observed 

that when other minnows 

saw one minnow eating, 

they quickly joined. Name 

one instance where you 

observed the same kind of 

behavior in humans. Your 

example does not have to 

be related to food, but to 

an observation of humans 

imitating or following others.

Adapted from Magaña, H.A. 2009. Feeding 

preference of the Rio Grande silvery minnow 

(Hybognathus amarus). Reviews in Fisheries Science. 

17(4):468-477. http://www.fs.fed.us/rm/pubs_other/

rmrs_2009_magana_h001.pdf.

If you are a trained 

Project Learning 

Tree educator, you 

may use Activity 

45: Web of Life or 

Activity 88: Life on 

the Edge.

abundant (a bun dənt): Marked by great 

plenty.

aquatic (ə kwä tik): Growing or living in or 

often found in water. 

debris (də brē): The remains of something 

broken down or destroyed.

divert (də vərt): To turn from one course or 

use, to another. 

eddy (e dē): A current of air or water running 

against the main current or in a circle. 

endangered (in dān jər ed): Being in danger 

or peril.

extinct (ik stiŋ(k)t): No longer existing.

habitat (ha bə tat): The environment where a 

plant or animal naturally grows and lives.

hatchery (ha chə rē ): A place for hatching 

eggs.

headwaters (hed wä tərz): The beginning 

and upper part of a stream or river.

meander (mē an dər): A turn or winding of 

a stream.

petri (pē trē): A small shallow dish with a 

loose cover used for cultures in science labs.

population (pä pyə lā shən): A group of 

one or more species of organisms living in a 

particular area or habitat. 

randomly (ran dəm lē): Selecting in such a 

way that each has an equal chance of being 

selected.

turbid (tər bəd): Clouded or discolored by 

the material from a liquid that settles to the 

bottom (sediment).

Accented syllables are in bold. Marks and definitions 

are from http://www.merriam-webster.com. 
38 Investi-gator • http://www.scienceinvestigator.org 

Materials 

• Bubble solution (purchased or create 

your own using 1 part dish soap to 10 

parts water)

• Drinking straws (2 per student)

• Yarn, cut into 2-foot sections 

(1 piece per student)

• Tray with edges (to hold bubble solution)

Time needed:

One class period.

The question 

you will answer 

in this FACTivity is:

How are diatoms important 

parts of an ecosystem? As 

you learned in the “By the 

Light of the Silvery Minnow” 

article, diatoms are onecelled organisms that live 

in colonies. A diatom’s cell 

wall is made of silica. In this 

FACTivity, you 

will create your 

own model of 

a diatom.

FACTivity

The method you will use to answer this question is:

1. You will need two drinking straws and a piece of yarn 

approximately 2 feet long. You will thread your yarn through 

the drinking straws and tie it at the end to create a rectangular 

shaped diatom model (figure 14). Your teacher will slowly pour 

the bubble solution into the tray, about 1centimeter in depth. 

Pouring slowly will prevent foaming. 

2. Taking turns with other students, you will use your straw and 

string model to create a diatom. Hold one of the straws of the 

model and immerse it into the tray of bubble solution. Gently 

raise it out of the pan and allow the extra soap to drip off. Hold 

your diatom up so that you can see the light reflecting off the 

silica cell wall. 
Investi-gator • http://www.scienceinvestigator.org 39

Figure 14: The 

diatom model 

will look similar 

to this when it 

is completed.

Illustration by 

Stephanie Pfeiffer.

3. After all of your classmates have created a bubble diatom model, your teacher will 

hold a class discussion about diatoms as a life-form. Some facts you may discuss 

are:

a. Diatoms are living aquatic organisms that use sunlight to turn carbon dioxide 

and water into food and oxygen.

b. Diatoms live in both fresh and salt water, in rivers, lakes, and ponds. They 

can be found throughout the world in areas that are wet. 

c. Algae are made up of diatoms. The green algae on stones at the water’s edge 

are likely a population of millions of tiny diatoms.

d. Diatoms are a basic, natural food source for many other animals, including 

silvery minnows. 

4. Using the article and class discussion as a reference, answer the question posed at 

the beginning of this FACTivity. Compare your diatom model with figure 8. What 

are the similarities 

and differences?

Web Resources

Diatoms

http://www.astrographics.com/

GalleryPrintsIndex/GP2006.html/

How to Make a Diorama Fish Habitat

http://www.ehow.com/how_8304459_makediorama-fish-habitat.html

Student-based Monitoring Program of the 

Rio Grande in New Mexico (video)

http://www.bosqueschool.org/bemp.aspx

Fish and Wildlife Service-Southwest Region 

Fisheries Education

http://www.fws.gov/southwest/fisheries/education.html

“By the Light of the Silvery 

Minnow” was taken from a song 

title. The song is “By the Light 

of the Silvery Moon.” The song 

was written and first recorded in 

1909 and was performed by Doris 

Day in 1953. The melody was also 

recorded by the Muppets in 2011.
Dr. Sharon Coe, 

wildlife ecologist

I have had wonderful experiences doing science 

outdoors. One of my favorite experiences was studying a 

bird. I studied mountain chickadees in a forest in the Sierra 

Nevada. The Sierra Nevada is a mountain range in California and 

Nevada. I was collecting data for my Ph.D. degree. People earning 

a Ph.D. degree become highly specialized in one research topic. 

I spent many weeks each summer observing the nesting behavior of 

mountain chickadees. I was able to see eggs and nestlings closeup. I enjoyed learning my way around the woods and knowing 

where the birds were nesting. My study sites were on lands 

managed by the Forest Service. After a while, the area 

became so familiar to me that it felt like it was my 

backyard. It was a big adventure!

Dr. Deborah Finch, 

biologist: 

One of my favorite scientific experiences is mistnetting and banding songbirds. A mist-net looks like a 

large volleyball net. The netting is very fine and almost 

invisible. Birds fly into the netting and get caught. Birds 

are not injured by mist-nets. After I carefully take each 

bird from the mist-net, I measure it and put a little 

numbered metal band around its ankle to keep track 

of it over time. Then, I love to open up my hands 

and watch the bird fly away.

Meet the 

Scientists!

Assessing How Climate Change 

May Affect Certain Wildlife

 U.S. Fish and Wildlife Service.Photo by Dave Menke and courtesy of

40 Investi-gator • http://www.scienceinvestigator.org 
Investi-gator • http://www.scienceinvestigator.org 41

Dr. Megan Friggens, 

ecologist: 

My first favorite science experience was taking a 

10-day field trip to Belize (bə lēz) as part of a college 

tropical biology class. Belize is in Central America. 

This trip was my first opportunity to travel to and live in a 

tropical jungle. I also explored Belize’s cays and reefs. I saw 

animals in the wild, such as howler monkeys and barracudas. I 

did a field study on a plant that eats insects. I also learned a lot 

about the local human populations. These people were often 

leading the efforts to conserve wild habitats and animal 

species. During this time I slept in a hammock, was 

attacked by tiny biting flies, and swam in crocodileinfested waters (the crocodiles were too small to 

hurt me). By the end of it all, I knew that I 

was going to be an ecologist.

What Kind of Scientist 

Did This Research?

biologist: This scientist studies living 

organisms and systems.

wildlife ecologist: This kind of scientist 

studies the relationship of different kinds 

of wildlife with each other and with their 

living and nonliving environment.

ecologist: This kind of scientist studies 

the relationship of living things with each 

other and with the nonliving environment.
42 Investi-gator • http://www.scienceinvestigator.org 

Thinking About the 

Environment

Have you heard the term “climate change?” 

Climate change refers to how Earth’s climate 

may be changing over time. In the past few 

years, most scientists have agreed that measured 

and recorded changes in Earth’s climate over 

the past 100 or more years point to a warming of 

Earth’s surface. 

Scientists are researching questions related 

to the possible effects of climate change. One 

question is: How do different plant and animal 

species respond to a changing climate? In this study, 

scientists were interested in how some vertebrates may

respond to climate change (figure 1). 

Thinking About Science

Sometimes scientists study current problems. Scientists 

also study problems that may occur in the future. To study 

what may happen in the future, scientists look at current 

evidence and make predictions about what might happen. 

In this study, the scientists were interested in how a 

changing climate may affect wildlife in the future. Scientists 

have tried to figure out the effects of climate change 

using several different methods. The method the scientists 

used in this study was to create a vulnerability index. A 

vulnerability index predicts how much a species might be 

affected by changes to their habitat. The scientists used this 

vulnerability index to predict which species of wildlife were 

likely to be the most vulnerable to climate change. This 

process enables people who work to conserve wildlife to 

make better decisions.

Figure 1. What is the difference between an 

invertebrate and a vertebrate?

Illustration by Stephanie Pfeiffer.
Investi-gator • http://www.scienceinvestigator.org 43

Introduction

Identifying which species may be the most vulnerable to a changing climate 

is important. This information can help people make decisions about how to best 

manage the land. It can also help make better decisions to support wildlife. In 

this study, the scientists wanted to learn more about species living in and around 

the Coronado National Forest (CNF) (figure 2). The CNF is located in southeast 

Arizona and southwest New Mexico (figure 3). The scientists 

identified 30 species to study.

Figure 2. The Coronado National 

Forest covers 1,780,000 acres 

of southeastern Arizona and 

southwestern New Mexico. Photo by 

Rod Replogle, Forest Service.

Figure 3. The Coronado National Forest is located in 

southeast Arizona and southwest New Mexico.
44 Investi-gator • http://www.scienceinvestigator.org 

Abert’s squirrel

Arizona 

ridge-nosed 

rattlesnake

Desert tortoise

Mexican 

long-tongued 

bat

Northern gray 

hawk

Townsend’s 

big-eared bat

Allen’s lappetbrowned batChiricahua 

leopard frog Elegant trogon Montezuma quail

Northern 

Mexican 

gartnersnake

Western 

yellow bat

American 

bullfrog

Chiricahua fox 

squirrel

Giant spotted 

whiptail

Mount 

Graham red 

squirrel

Slevin’s 

bunchgrass 

lizard

Western 

yellow-billed 

cuckoo

American 

peregrine falcon

Coues’ whitetailed deerGould’s wild 

turkey

Northern 

buff-breasted 

flycatcher

Sonoran tiger 

salamander

Western red 

bat

Arizona gray 

squirrel

Desert bighorn 

sheep Mesquite mouse Northern goshawk

Tarahumara 

frog

White-bellied 

long-tailed 

vole

Figure 4. The 30 different species that the scientists studied 

included 8 birds, 13 mammals, 5 reptiles, and 4 amphibians. 

The 30 species the scientists studied included reptiles, amphibians, birds, and 

mammals (figures 4, 5a, & 5b). Some of these 30 species were important to study 

because they were considered at risk of extinction. Some of the species were 

already listed as an Endangered Species or a Federal Species of Concern. 

Figure 5a. The Chiricahua (chir ə kä wə) 

leopard frog is a threatened species. Under 

the Endangered Species Act of 1973, 

a threatened species means that the 

species is “likely to become endangered 

in the foreseeable future throughout all 

or a significant portion of its range.” An 

endangered species is one in which the 

entire species is in danger of extinction. 

When a species is extinct, no individuals 

of that species are alive. Photo courtesy of Jim 

Rorabaugh, U.S. Fish and Wildlife Service.
Investi-gator • http://www.scienceinvestigator.org 45

Figure 5b. The American 

peregrine falcon is a fast flier. 

The falcon averages 25-34 

miles per hour in traveling 

flight. The falcon can reach 

up to 69 miles per hour when 

pursuing prey. Photo courtesy of 

Andrew Kuhn, National Park Service.

The scientists in this study were interested in discovering how climate change may 

affect the 30 species they studied. The scientists wanted to figure out how vulnerable

the species may be to climate change. 

Methods

To figure out which species were likely to 

be the most vulnerable to the effects of climate 

change, the scientists used a vulnerability index. 

The scientists answered 25 questions for each 

species. The 25 questions were grouped into 

four categories. 

The four categories were habitat, physiology 

(fi zē ä lə jē), phenology (fi nä lə jē), and biotic 

(bī ä tik) interactions. The habitat category 

covered topics about where an animal lives. The 

physiology category covered topics related to 

the function and activities of the animal. 

Phenology is the study of the relationship 

between climate and events in the annual life 

cycle of plants and animals. Example topics in 

the phenology category are bird migration and 

In your own words, state 

what the scientists wanted 

to know. 

Why do you think the 

scientists chose some of 

these 30 species?
46 Investi-gator • http://www.scienceinvestigator.org 

Figure 6. Examples of different types of questions the scientists asked in 

each category. 

Habitat

• Where is the breeding area?

• What resources are needed in the 

habitat during the breeding season? 

• Where is the non-breeding area?

• How well is the species able to make 

homes in new areas?

• Does the species use migratory areas?

Physiology

• How does the species respond to 

extreme weather?

• Would climate change limit the daily 

active period for the species?

• What is the species’ life span?

• What is the ability of the species to 

store energy?

Phenology

• How does the species use temperature 

and moisture as cues for changes in 

behavior?

• How many times does the species 

attempt to breed in a year?

Biotic Interactions

• If the species has a specific diet, what 

are the impacts of climate change on 

the primary food sources?

• Is there potential for changes in the 

amount that diseases are spread?

The scientists answered these types of questions for each of the species in their study. Each 

question was scored a point value depending on the answer to the question. The scientists 

calculated an overall score for each species using points from answers to all 25 questions. 

The scientists also calculated a score for each species in each of the four categories (using 

points from only the questions within the category). 

In addition, the scientists calculated a score for the four different taxonomic groups they 

studied. They calculated this score by taking the average of the overall score for each species 

in a taxonomic group. The four taxonomic groups that were studied were birds, mammals, 

amphibians, and reptiles. 

In summary, the scientists calculated three scores: 1) an overall score for each species; 2) a 

score for each category for each species; and 3) a taxonomic group score.

plant flowering. Migration is when an animal moves from one region or climate to another 

for feeding or breeding.

Biotic interactions are the ways that living things interact with each other. The questions 

in this category related to how these interactions might change due to a changing climate. 

Examples of the types of questions the scientists answered are shown in figure 6.
Investi-gator • http://www.scienceinvestigator.org 47

Why do you think the scientists looked at an overall 

score for each species, category scores for each 

species, and taxonomic group scores? 

Look at figure 6 under biotic interactions. Why might it 

be important to know if there may be a change in the 

amount of diseases that are spread?

Findings

The scientists found that most of the 

species were vulnerable to climate change. 

The overall score ranged from -0.4 to 9.9. 

The larger the overall score, the more 

vulnerable the species was to a changing 

climate. 

Sixty-seven percent of 

the species identified had 

a score over 5. These were 

the species most vulnerable 

to climate change. The two 

species with the largest 

scores were the elegant 

trogon (trō gän) and the 

Tarahumara (ta rə hü mär 

ə) frog (figures 7 & 8). The 

lowest scoring species were 

the mesquite mouse, the 

desert bighorn sheep (see 

photo, upper right), and Slevin’s bunchgrass 

lizard. These three species were predicted to 

be the least vulnerable to climate change. 

Figure 8. The 

Tarahumara frog does 

not have vocal sacs 

like most male frogs. 

Vocal sacs are a thin 

piece of skin that, when 

filled with air, enables a 

male frog to call loudly. 

The Tarahumara frog 

still manages to make 

sounds, such as grunts and snores, above 

and below the water. Photo courtesy of Jim 

Rorabaugh, U.S. Fish and Wildlife Service.

Figure 7. The 

elegant trogon’s 

population is 

estimated to be 

around 200,000 

birds. Photo courtesy 

of Dominic Sherony 

(Wikimedia Commons).

Photo by Fernley and Dreamstime.
48 Investi-gator • http://www.scienceinvestigator.org 

When the scientists looked at the different taxonomic groups they studied, they found that 

the bird group had the highest average overall score and the reptile group had the lowest average 

overall score (figure 10). 

Figure 9. The highest and lowest scoring species for habitat, physiology, and 

phenology. The closer the score was to 5, the more vulnerable the species was 

predicted to be in each category. 

Category Species Score

Habitat (highest score) Chiricahua leopard frog 4.0

Habitat (lowest score) Slevin’s bunchgrass lizard -2.3

Physiology (highest score) Tarahumara frog and 

Chiricahua leopard frog

2.9 (for both)

Physiology (lowest score) Townsend’s big-eared bat -0.8

Phenology (highest score) Elegant trogon 5.0

Phenology (lowest score) Mesquite mouse -3.3

Taxonomic Group Average Overall Score

Birds 7.4

Amphibians 6.9

Mammals 5.0

Reptiles 3.9

Figure 10. The scores for the 

taxonomic groups showed 

that all of the groups were 

vulnerable to climate change. 

Look at figure 9. List one thing you notice when studying this table.

Look at figure 10. What do you notice about the scores for the four 

taxonomic groups?

Scientists calculated scores for each species within the four categories. The scores 

ranged from -2.3 to 5 for habitat, physiology, and phenology. The closer the score was to 5, 

the more vulnerable the species was predicted to be in that category (figure 9). 
Investi-gator • http://www.scienceinvestigator.org 49

Discussion

The scientists concluded that most of the 30 species are vulnerable to a changing 

climate. The scientists suggested that the scores for each species may be used as a 

guide. These scores may help guide which species should be studied more right now. 

Also, the scientists believe it is important to look at the individual characteristics 

of each species. These individual characteristics may have an impact on the 

vulnerability of a species. 

The scientists also said it was important to consider the overall score as well 

as the scores within the categories (habitat, phenology, physiology, and biotic 

interactions). For example, the elegant trogon and Tarahumara frog had the same 

overall score. However, they had different scores within the four categories. The 

scores within the categories may help scientists know which areas need more study.

Do you think it is useful to figure out how vulnerable a species is to 

climate change? Why or why not? 

Take a moment to think about all the members of your class. Write 

down three words to describe your entire class. For example, you could 

say energetic, smart, and fun-loving. Now take a moment to think about 

yourself. Write down three words to describe you. Did the three words 

that you wrote about the entire class and the three words you wrote 

about yourself match perfectly? How is this like what the scientists 

found out about the different species when they used the overall score, 

the category score, and the taxonomic group scores? 

Adapted from Coe, Sharon J.; Finch, Deborah M.; 

Friggens, Megan M. 2012. An assessment of climate 

change and the vulnerability of wildlife in the Sky Islands 

of the Southwest. Gen. Tech. Rep. RMRS-GTR-273. 

Fort Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station. 208 p. http://

www.fs.fed.us/rm/pubs/rmrs_gtr273.pdf.

If you are a trained Project 

Learning Tree educator, you 

may use Activity 86: Our 

Changing World or Activity 

88: Life on the Edge. 
50 Investi-gator • http://www.scienceinvestigator.org 

Glossary

average (av(ə-) rij): A value equal to the sum of a set of numbers divided by how many 

numbers are in the set.

cay (kē): Small, low-lying sandy island formed on the surface of a coral reef.

conserve (kən sərv): To avoid wasteful or destructive use of.

endangered species (in dān jər ed spē shēz): A species threatened with extinction.

extinction (ik stiŋ(k) shən): The state or situation that results when something (such as a 

plant or animal species) has died out completely. 

Federal Species of Concern (fe d(ə-)rəl spē shēz əv kən sərn): Species which might 

need special help. Species of concern do not receive legal protection. 

habitat (ha bə tat): The environment where a plant or animal naturally grows and lives.

reef (rēf): A chain of rocks or coral or a ridge of sand at or near the surface of the water.

specialized (spe shə līzd): Trained, or fitted for one particular purpose or occupation.

species (spē shēz): A class of individuals having common attributes and designated by a 

common name.

taxonomic (tak sä nə mik): Orderly classification of plants and animals according to their 

presumed natural relationships.

vertebrate (vər tə brət): Having a spinal column.

vulnerable (vəl n(ə-) rə bəl): Open to attack or damage.

vulnerability (vəl n(ə-) rə bəl ə tē): The state of being vulnerable.

vulnerability index (vəl n(ə-) rə bəl ə tē in deks): A system for generating a number 

that indicates how vulnerable something is to something harmful. In this study, scientists 

collected data about each species and then answered questions about how each species 

could be affected by climate change. The scientists then were able to calculate numbers, 

called scores. Higher scores indicated higher predicted vulnerability.

Accented syllables are in bold. Marks and definitions are from http://www.merriam-webster.com. 
Investi-gator • http://www.scienceinvestigator.org 51

Materials 

• Investi-gator Animals and Ecosystems

of the Southwestern United States

• Computer with Internet access or hard 

copy field guides for birds, mammals, 

reptiles, and amphibians

Time needed:

Two class periods.

The question 

you will answer 

in this FACTivity is:

How might climate change 

affect species in my state? 

FACTivity

The method you will use to answer this question is:

1. Divide into small groups of three to four students. You and your group will 

choose four animals that are found in your state. These animals can be birds, 

mammals, amphibians, or reptiles. One of these animals should be at risk of 

extinction. This species should be listed as a Federal Endangered Species or 

a Federal Species of Concern. To find endangered animals in your state, visit 

the U.S. Fish and Wildlife Service’s Endangered Species Program Web site 

at http://www.fws.gov/endangered/. 

Once you have chosen four animals, you will answer a few questions to help 

determine the vulnerability of each animal. Use the internet or field guides 

to answer the following questions about each animal:

a. Where is the species’ breeding area?

b. How many times a year does the species attempt to breed?

c. What is the species’ life span?

d. Does the species have a specific diet?
52 Investi-gator • http://www.scienceinvestigator.org 

2. After you and your group have answered the questions about each species, discuss the 

potential impacts climate change could have on these species. Some questions you may 

ask are:

a. How might climate change affect the species’ breeding habits? Will it 

shorten or lengthen the breeding period? Will the species have to travel 

further to reach its breeding area?

b. Will climate change affect how many times a year the species breeds? 

For example, if it only breeds during the winter and winters become 

shorter, will the species be able to breed as often?

c. How might climate change affect the species’ life span? Will the species 

live for a longer or shorter amount of time?

d. How will the species’ diet change as a result of climate change? Will the 

food it eats still be available?

3. As a class, discuss the information you learned about climate change and animals in 

your state. Compare what you discover with the findings from this article. Now, answer 

the question posed at the beginning of the FACTivity. 

Web Resources

Coronado National Forest

http://www.fs.usda.gov/main/coronado/home

Information about the Mexican Frog or Tarahumara Frog

http://www.azgfd.gov/w_c/edits/documents/Ranatara.fi.pdf

Teachers Guide for “Climate Change, Wildlife, and Wildlands Toolkit”

http://www.globalchange.gov/resources/educators/toolkit

FACTivitycontinued

Photo courtesy of Gila National Forest.
Investi-gator • http://www.scienceinvestigator.org 53

Meet the Scientists! Dr. Darin Law, 

plant ecologist:

My favorite science experience was 

completing a native and exotic grass 

study within the University of Arizona 

Biosphere 2 (figures 1a and 1b). Biosphere 

2 is a research facility where scientists perform 

experiments. Biosphere 2 also enables public 

participation in the scientific process. Biosphere 

2 is a large enclosed building that simulates

different ecosystems.

It was especially fun to talk with students from 

nearby schools who came to tour Biosphere 2. I 

told students about the work I do as a scientist. 

From the time I was young, I watched PBS 

Nature every Sunday evening. This TV show 

had a tremendous influence on my life. 

Now, I measure how plants respond to 

environmental conditions outside and 

inside Biosphere 2. When I make my 

measurements, I like to imagine that 

my work is being filmed for the 

PBS program Nature.

How Do Streams Affect 

How Well Trees Use Water?

Streaming Live:

Figure 1a. Biosphere 2 is a large building that is completely closed to 

the outside environment. Within Biosphere 2, different land and marine

environments are simulated. Scientific research is done within these 

environments. Photo courtesy of John Adams, University of Arizona, Biosphere 2.
54 Investi-gator • http://www.scienceinvestigator.org 

biologist: This scientist studies living organisms and systems.

plant ecologist: This scientist studies the relationships between 

plants and their environment.

What Kind of Scientist Did This Research?

Figure 1b. Inside Biosphere 

2, different environments 

have been created. This 

water body simulates an 

ocean. Photo courtesy of John 

Adams, University of Arizona, 

Biosphere 2.

Dr. Deborah Finch, 

biologist: 

One of my most favorite science 

experiences was climbing with pack burros 

to the top of El Triunfo (trī ün fō), a Biosphere

Reserve in southern Mexico. I was searching 

for the resplendent (rə splən dənt) quetzal (ket 

säl). The resplendent quetzal is a tropical bird 

with bright green feathers and a long tail. We 

were setting up a sister forest program with 

Mexican protected areas. This reserve 

was famous for protecting this 

spectacular bird!
Thinking About Science

Scientists use a lot of interesting and useful instruments. Technology 

improves the accuracy of scientific measurement. Technology has also enabled 

scientists to measure some things they could not measure in the past. 

In this research, the scientists used a densiometer (den sē ä mə tər) to 

measure the amount of leaf cover (shade) in forested areas. The scientists 

used a porometer (pȯ rä mē tər) to measure the amount of carbon 

dioxide (CO2

) entering and the amount of water exiting leaf pores. 

The scientists took measurements from thermometers, 

barometers, and anemometers (an ə mä mə tərs). Thermometers 

measure temperature. Barometers measure atmospheric pressure. 

Anemometers measure wind speed. The scientists used quantum 

meters (figure 1) to measure the amount of light reaching tree 

leaves. They used water level meters to measure the distance 

between the ground’s surface and the top level of the water 

underground (groundwater). What do most of these instrument 

names have in common? What does “meter” tell you when it is the 

last five letters of a word? 

Figure 1. Quantum 

meters measure the 

amount of light. Photo 

courtesy of University of 

Georgia Warnell School 

of Forestry and Natural 

Resources. Photo by Jean 

Szymanski.

Investi-gator • http://www.scienceinvestigator.org 55
56 Investi-gator • http://www.scienceinvestigator.org 

Thinking About the Environment

The Southwestern United States contains much arid land (figure 2). Arid 

land has little water. In an area with little water, streams are important. Of all the 

streams in the Southwestern United States, 19 percent have water all year. The 

remaining 81 percent are either intermittent (in tər mit ənt) or ephemeral (əf əm 

ər äl) (figures 3a and 3b). An intermittent stream has water for only part of the 

year. An ephemeral stream has water only following rain storms.

Although intermittent and ephemeral streams may not always have water you can see, 

these streams contribute to the area’s groundwater. Groundwater is water found under the 

soil’s surface. Groundwater from these streams supports plants that otherwise could not 

live in arid environments. These streams also provide benefits when they have water you 

can see. These streams provide breeding habitat for amphibians. Streams also cool the 

nearby air. 

In this research, the scientists were interested in groundwater near intermittent and 

ephemeral streams. The scientists wondered how trees growing near and away from 

these streams used available groundwater. Since water is necessary for plants to survive, 

groundwater is important to plants. This is especially true during times of low or no 

rainfall, when most available water is groundwater.

Figure 2. The Forest Service 

identifies the Southwest as 

including the states of Arizona, 

New Mexico, and western parts 

of Oklahoma and Texas. The 

dark areas show the location of 

national forests.
Investi-gator • http://www.scienceinvestigator.org 57

Figure 3a. Intermittent streams 

have water during the rainy season. 

Ephemeral streams have water 

only after a rain. This illustration 

shows either an intermittent or an 

ephemeral stream during its wet 

season. Illustration by Stephanie Pfeiffer.

Figure 3b. Intermittent streams are 

dry during dry seasons. Ephemeral 

streams are dry between periods of 

rain. This illustration shows either 

an intermittent or an ephemeral 

stream during its dry season. 

Illustration by Stephanie Pfeiffer.

Introduction

Imagine a tree during times of low or 

no rainfall. To survive, this tree must use 

groundwater. Water in arid environments, 

including groundwater, is scarce. Trees, 

therefore, need to use groundwater efficiently. 

Groundwater is absorbed by a tree’s roots. 

The groundwater moves upward toward the 

leaves. The water carries nutrients with it 

(figure 4). The leaves use some of the water for 

photosynthesis. Leaves have small openings 

called stomata. When a leaf’s stomata are open, 

some of the water escapes into the air. 

The process of water movement from inside 

the leaf into the air is called transpiration. 

Water is pulled upward through a tree similar 

to the way liquid is pulled upward through a 

straw. Transpiration helps move water from the 

ground into the roots, through the stem, and out 

of the leaves into the air. When stomata close a 

little or completely, transpiration is reduced or 

stopped. Think about what happens when the 

end of a straw is pinched.

Stomata have another job to do. When 

open, stomata allow carbon dioxide (CO2

) from 

the air to enter the leaf. In addition to water, 

trees need CO2 for photosynthesis (figure 5).

Photosynthesis is the process whereby trees use 

sunlight to change CO2 to high-energy sugar. 

The trees use the sugar as food. The energy 

stored in the sugar enables trees to grow.
58 Investi-gator • http://www.scienceinvestigator.org 

Figure 4. Water is carried upward from a tree’s roots through the 

tree’s xylem (zī ləm). Water exits the tree through stomata in the 

leaves. Illustration by Stephanie Pfeiffer.

Open stomata are necessary for 

photosynthesis. Open stomata, however, 

can lower a tree’s water use efficiency. 

When water is scarce, a tree has to balance 

transpiration (water loss) with the CO2 

it takes in. When a tree uses scarce water 

efficiently, two things happen. First, the tree 

maximizes photosynthesis. Second, the tree 

minimizes water loss.

The scientists in this study were 

interested in comparing the water use 

efficiency of trees. They wondered if the 

water use efficiency of trees growing away 

from intermittent and ephemeral streams was 

greater than the water use efficiency of trees 

growing near such streams. Compare this 

to a person using something more carefully 

because they only have a limited amount 

of it. The scientists also wondered if other 

nearby trees and wind speed affected the 

water use efficiency of trees. 
Investi-gator • http://www.scienceinvestigator.org 59

What problem do trees face when 

growing where water is scarce?

How might nearby trees affect a tree’s 

water use efficiency? 

How might wind speed affect a tree’s 

water use efficiency? 

Figure 5.

Photosynthesis is the 

process plants use to 

convert sunlight into 

energy in the form of 

glucose. Illustration by 

Stephanie Pfeiffer. 
60 Investi-gator • http://www.scienceinvestigator.org 

Figure 7. Weather stations were set 

up to measure air temperature, relative 

humidity, wind speed, and rainfall. This 

is a weather station at the University 

of Georgia. Photo courtesy of University of 

Georgia Department of Geography. Photo by 

Jean Szymanski.

Figure 6. The scientists dug 

shallow water wells to check for 

groundwater. The wells were thin 

pipes with small holes. The pipes 

were placed deep into the soil. 

The holes allowed groundwater 

into the pipe. The scientists 

then measured the distance 

between the soil surface and the 

groundwater in the pipe below the 

soil surface. Illustration by Stephanie 

Pfeiffer. 

Methods

First, the scientists needed to know if areas next to and away from intermittent and 

ephemeral streams had groundwater. They also needed to know how far the groundwater was 

from the soil surface. The scientists dug shallow water wells next to and away from intermittent 

and ephemeral streams and measured the groundwater depth (figure 6).

The scientists needed a way to measure the 

abundance of trees growing in an area. They did 

this by measuring the amount of shade cover 

in an area. Shade cover can be measured by 

the percentage of an area covered by leaves. 

The scientists also measured air temperature, 

relative humidity, wind speed, and rainfall 

(figure 7). They measured the amount of light 

reaching the trees (figure 8). The scientists 

measured the amount of CO2

 entering and the 

amount of water exiting the leaf pores (figure 

9). The scientists also selected leaves from 

some of the trees and traced the leaves on paper. 

They then calculated the area of each leaf to 

compare leaf sizes from different trees.
Investi-gator • http://www.scienceinvestigator.org 61

Figure 8. A densiometer measured the 

amount of canopy cover. Canopy cover is the 

percentage of leaves shading the ground. Photo 

courtesy of University of Georgia Warnell School of Forestry 

and Natural Resources. Photo by Jean Szymanski.

Figure 9. A porometer measured the amount of CO2 entering 

and the amount of water exiting a leaf pore. Photo courtesy of 

University of Georgia Warnell School of Forestry and Natural Resources. 

Photo by Jean Szymanski. 

The scientists used a computer program 

to compare all of these things. The scientists 

compared the amount of photosynthesis 

with the amount of water transpired. This 

comparison was used as a measure of water 

use efficiency. The scientists then compared 

the water use efficiency of trees growing near 

and away from intermittent and ephemeral 

streams. They also compared the water use 

efficiency of trees growing with many trees 

nearby and with few trees nearby. 
62 Investi-gator • http://www.scienceinvestigator.org 

Why did the scientists need to know how much rain had fallen? 

As Earth’s climate changes, some areas may receive less rainfall. 

Could this research be useful to people living in areas that already 

have enough rainfall? Why? 

Findings

The scientists discovered relationships among water use efficiency, photosynthesis, 

transpiration, and leaf size (figure 10).

The areas with highest water use efficiency were the areas with few trees growing away 

from streams. The areas with lowest water use efficiency were the areas with many trees 

growing close to streams. High amounts of sunlight and low transpiration seem to favor a 

more efficient use of water. When water use efficiency is high, leaf size is smaller. When 

water use efficiency is low, leaf size is larger. 

When trees are not growing near each other, wind speed is higher and transpiration 

increases. When many trees are growing close to each other, wind speed is lower and 

transpiration decreases.

The scientists compared trees in four areas (see figure 10): 

1. Areas with many trees growing away from intermittent and ephemeral streams.

2. Areas with many trees growing close to intermittent and ephemeral streams.

3. Areas with few trees growing close to intermittent and ephemeral streams.

4. Areas with few trees growing away from intermittent and ephemeral streams.
Investi-gator • http://www.scienceinvestigator.org 63

Least Efficient Water Use Most Efficient Water Use

Look at figure 10. What 

can you conclude from 

this figure? 

Why do trees growing 

closer to intermittent 

and ephemeral streams 

not need to be as 

efficient with water use 

as trees growing away 

from streams? 

Figure 10. What are the relationships between 

water use efficiency, leaf size, photosynthesis, 

and transpiration? Illustration by Stephanie Pfeiffer.

Photo courtesy of Gila National Forest.
64 Investi-gator • http://www.scienceinvestigator.org 

Are you surprised that trees respond to environmental conditions? 

Why? What is another example of plants responding to their 

environment?

In the human body, what mechanism is similar to transpiration? 

Adapted from Law, D.J.; Finch, D.M. 2010. 

Hydrologic, abiotic and biotic interactions: plant 

density, windspeed, leaf size and groundwater all 

affect oak water use efficiency. Ecohydrology. 

4:823-831. http://www.fs.fed.us/rm/pubs_other/

rmrs_2011_law_d001.pdf

Discussion

Based on their results, the scientists suspect something important about CO2 gain and water loss 

in trees. They believe that trees work to balance CO2 gain with water loss to remain healthy. In areas 

with scarce water, trees try to absorb more CO2

 and transpire less water. To achieve this balance, trees 

open or close their stomata to increase water use efficiency. If trees are growing close to other trees, 

the trees increase their leaf size to help absorb more CO2. 

The scientists noted that trees responded to many things in their environment. Trees responded 

to the amount of light and water available. The trees responded to the number of other trees growing 

nearby. The trees also responded to wind speed. Trees must respond to all of these conditions. When 

water is scarce, trees must increase their water use efficiency. They increase water use efficiency by 

decreasing the amount of water they lose and increasing the amount of light and CO2

 they absorb.
Investi-gator • http://www.scienceinvestigator.org 65

absorption (əb sȯrp shən): The process of 

taking in.

amphibian (am fib bē ən): An organism 

that lives both on land and in water; a class 

of cold-blooded vertebrate animals. 

arid (a rəd): Excessively dry.

biosphere (bī ə sfir): The part of the 

world in which life exists. In this article, 

Biosphere 2 is the name of a man-made 

enclosed area that supports life and a 

biosphere reserve is a protected natural area 

that supports a diversity of life.

breeding habitat (brēd iŋ ha bə tat): 

An environment where a plant or animal 

naturally reproduces.

canopy (ka nə pē): Anything that covers 

like a roof. On a tree, the area of leaves that 

covers the ground.

decay (di kā): To break down, rot, or 

undergo decomposition.

efficient (i fi shənt): Capable of getting 

desired results without waste. 

exotic (ig zä tik): Strange, different, or 

foreign.

groundwater (grau̇nd wä tər): Water that 

is underground.

habitat (ha bə tat): The environment where 

a plant or animal naturally lives and grows.

intensity (in ten sə tē): The quality or state 

of being extreme in strength or force.

marine (mə rēn): Of or relating to the sea.

native (nā tiv): Living or growing naturally 

in a particular region.

nutrient (nü trē ənt): A substance that 

plants, animals, and people need to live and 

grow.

photosynthesis (fō tō sin thə səs): The 

process by which plants turn water and 

carbon dioxide into food when exposed to 

light.

relative humidity (re lə tiv hyü mi də tē): 

The amount of water vapor actually present 

in the air compared to the greatest amount 

possible at the same temperature.

scarce (skers): Not plentiful.

simulate (sim yə lāt): To create the 

appearance or effect of something for 

purposes of evaluation.

transpiration (tran(t)s pə rā shən): The 

process by which plants give off water 

vapor through the stomata in their leaves. 

unit of measurement (yü nət äv me zhər 

mənt): A quantity used as a standard of 

measurement.

urban forest (ər bən fȯr əst): Trees and 

other vegetation growing within a city or 

town.

variable (ver ē ə bəl): Something that, 

when its quantity is measured, can have a 

range of different values.

If you are a trained Project Learning Tree educator, you may use 

Activity 41: How Plants Grow or Activity 42: Sunlight and Shades 

of Green.

Glossary

Accented syllables are in bold. 

Marks and definitions are from 

http://www.merriam-webster.com. 
66 Investi-gator • http://www.scienceinvestigator.org 

Materials 

• Access to the Media Center or the Internet

• Graphic organizers on pages 68-69

• “Streaming Live” article

Time needed:

One class period and, optionally, an additional 

30 minutes in a second class period

In this FACTivity,

you will explore a range 

of instruments used by 

scientists. You will then use 

your imagination to create 

instruments that measure 

a range of classroom 

variables.

FACTivity

In this article, the scientists used the following 

instruments to collect, measure, and record data:

Instrument Measures

Thermometer Air temperature

Barometer Relative humidity

Anemometer Wind speed

Porometer Pore opening size 

(stomata opening size)

Densiometer Tree canopy cover

Water well meter Depth from soil surface 

to ground water

Quantum meter Light intensity

If you read “Thinking About Science,” you 

will have a good idea of what the word “meter” 

at the end of each of these instrument names 

means. It gives you a clue that the first part 

of the instrument name tells what variable the 

instrument measures. 

The questions you will answer in 

this FACTivity are:

1. What are at least five more 

instruments with the word 

“meter” in their name, and 

what variables do they 

measure?

2. What instrument names can be 

created for imaginary use in 

the classroom and what unit 

of measurement would these 

instruments use?

3. What are the characteristics of 

a useful unit of measurement?

4. How does having a 

measurement range help 

someone to understand the 

measurement?
Investi-gator • http://www.scienceinvestigator.org 67

The method you will use to answer this question is: 

1. Your class should first brainstorm any additional instruments you know 

ending with the letters “m-e-t-e-r.” These instruments should be written 

in the graphic organizer given in the next section. You should then 

do research on the Internet or in your Media Center about scientific 

instruments. Record any instrument ending with the five letters “meter” 

and what variable it measures in the graphic organizer. To complete 

the graphic organizer, you should also fill in the column named “unit 

of measurement.” The unit of measurement is the numeric unit used 

to measure the variable. A thermometer, for example, measures the air 

temperature in degrees Fahrenheit or Celsius. Your class should identify 

as many instruments as possible.

2. After you have identified instruments, it is time to get creative! Using the 

second graphic organizer, imagine instruments that measure variables that 

could be found in the classroom. Below are examples. Remember that 

these are not real instruments!

Instrument Name Measures Unit of Measurement Measurement Range

Footometer 

(fö tə mə tər)

Foot length Inches or 

centimeters

6 inches-15 inches 

(15.24- 38.1 centimeters)

Silencometer 

(sī lən sö mə tər)

The amount of time 

students have been 

silent

Seconds or minutes 0-600 seconds 

or 0-10 minutes

Jumpometer 

(jum pö mə tər)

How far or high a 

student can jump

Feet or meters 6 inches-4 feet 

(0.15-1.22 meters)

3. After the created instruments have been identified and the graphic organizer 

is completed, your teacher will lead a class discussion about scientific 

instruments. In particular, you will discuss the need for a clear unit of 

measurement and a measurement range. Discuss and answer the following 

questions:

a. What are the characteristics of a useful unit of measurement?

b. How does having a measurement range help you understand the 

measurement?

While doing Internet or Media Center research, other instrument names may 

have been found. An example is “rain gauge.” You should realize that scientific 

instruments do not all end with the five letters that spell “meter.” 
68 Investi-gator • http://www.scienceinvestigator.org 

FACTivity continued

Instrument Name Measures Unit of Measurement

Your teacher will lead a class discussion in which you explore 

how the use of scientific instruments helped the scientists in this 

study do their research.

Scientific Instruments
Investi-gator • http://www.scienceinvestigator.org 69

Instruments That Might Be Used in the Classroom

Optional (using an additional 30 minutes at the 

end of a week): Student teams identify additional 

real scientific instruments and/or create new 

imagined instruments over a week’s period. The 

team with the longest (and best documented) list of 

instruments wins. All listed instruments, whether 

real or imagined, must include the four columns 

shown in the second graphic organizer. Students 

will present their instruments and the class will pick 

the team winner.

For a FACTivity about leaf 

transpiration, see the FACTivity 

for the “Woolly Bully” 

monograph at http://www.

naturalinquirer.org.

Instrument Name Measures Unit of 

Measurement

Measurement 

Range

Web Resources

Weather instruments

http://www.weatherwizkids.com/

weather-instruments.htm

Biosphere 2

http://www.b2science.org/

What is a densiometer?

http://www.youtube.com/watch?v=nTc_

sqUPVZo

We need trees!

http://kids.discovery.com/tell-me/earth/

why-do-we-need-trees

Do trees grow on farms?

http://www.realtrees4kids.org/index.htm
70 Investi-gator • http://www.scienceinvestigator.org 

Dr. Megan Friggens, 

ecologist

My first favorite science experience was taking 

a 10-day field trip to Belize (bə lēz) as part of a 

college tropical biology class. Belize is in Central 

America. This trip was my first opportunity to travel 

to and live in a tropical jungle. I also explored Belize’s 

cays and reefs. I saw animals in the wild, such as howler 

monkeys and barracudas. I did a field study on a plant that 

eats insects. I also learned a lot about the local human 

populations. These people were often leading the efforts 

to conserve wild habitats and animal species. During 

this time I slept in a hammock, was attacked by tiny 

biting flies, and swam in crocodile-infested waters 

(the crocodiles were too small to hurt me). By 

the end of it all, I knew that I was going to 

be an ecologist.

Dr. Bob Parmenter,

chief scientist, biologist, and 

ecologist

My favorite science experience was (and still is) 

tracking the recovery of the plants, fish, and wildlife 

following the very large Las Conchas wildfire. This 

wildfire burned through northern New Mexico in the 

summer of 2011. I monitor the populations of bears, 

mountain lions, elk, deer, squirrels, mice, birds, 

salamanders, and fish. I also monitor invertebrates, 

including grasshoppers, beetles, spiders, ants, 

wasps, butterflies, and moths. It’s fascinating to 

see how all these species respond to large 

forest fires in New Mexico.

Meet the Scientists!
Investi-gator • http://www.scienceinvestigator.org 71

Dr. Kenneth Gage,

medical entomologist and zoologist

My favorite science experience happened while working 

at the Centers for Disease Control and Prevention. I was 

traveling to a remote village in the Andes Mountains of 

Peru. An outbreak of plague was occurring in the village. 

Plague is a rare but dangerous disease that can be fatal if 

not quickly treated with the right medicines. Humans can 

get the disease when they are bitten by infected fleas or 

handle infected animals. 

In the village, some people had become sick after 

handling infected animals. Others had become ill after 

being bitten by infected fleas found in their homes or 

fields. The village could not be reached by road. My 

Peruvian colleagues and I had to ride mules up a very narrow trail that 

often passed by steep slopes and cliffs. In addition to riding mules, we also used seven 

small donkeys to carry the equipment and supplies needed to control the outbreak. 

At one point, a rope used to tie some of the equipment to one of the donkeys broke. 

This caused the donkey to begin kicking. As it kicked, the equipment bounced up 

and down, making loud noises that frightened the mules and donkeys and caused 

them to begin braying loudly. At the same time, my mule started to buck, causing the 

stirrup on my saddle to break off. At that point, I was barely holding on and thought I 

was going to be bucked off my mule and over a cliff. Fortunately, I was able to hang 

on and made it safely to the village. The people there treated us kindly and greatly 

supported our work, making this trip a memorable and rewarding experience. 

In this photo, I am investigating a case of human plague.

Dr. Paulette Ford,

ecologist

My favorite science experiences are when I 

am outside at my experimental research sites. I 

love to be outside studying plants and animals! 

As a scientist, I also get to travel around the world 

to talk about my research and to explore different 

ecosystems. I’ve been to grasslands, forests, 

jungles, deserts, mountains, oceans, rivers, and 

swamps all over the world. I never stop 

learning, and that is big fun!
72 Investi-gator • http://www.scienceinvestigator.org 

What Kind of Scientist Did This Research?

ecologist: This scientist studies the relationship of living things 

with each other and with the nonliving environment.

chief scientist: This scientist leads other scientists in a 

particular research area.

biologist: This scientist studies living organisms and systems.

medical entomologist: This scientist studies medically 

important arthropods, such as fleas, ticks, and mosquitoes.

zoologist: This scientist studies animals and animal life.

When scientists start a research project, 

they must do several things. First, they identify 

the problem they are interested in researching. 

Second, scientists develop a research question. 

Next, they design a study that helps them 

answer their research question. 

It is not easy to design a study to answer a 

research question. To design a study, scientists 

must read a lot about the topic of interest. 

Scientists also need to find out if other research 

has been done on this topic. If other research 

has been done, scientists learn about what the 

other scientists did and how it 

applies to their new study. After 

scientists have done this reading 

and research, they design their 

study. In this article, scientists 

designed a research study to 

learn more about how plague 

affects prairie dogs and their 

environment. Plague is a disease 

that is easily spread to other 

animals. 

Thinking About Science

Thinking 

About the 

Environment

A prairie dog is not really 

a dog! It is a large ground 

squirrel, a type of rodent, 

which lives on the prairie 

(figures 1a, 1b, and 2). 

Prairie dogs get their name 

from where they live and the 

“barking” sound they make. 

Prairie dogs make this sound 

to communicate with other 

prairie dogs. 
Investi-gator • http://www.scienceinvestigator.org 73

Figures 1a and 1b.

Prairies are wide open 

spaces with grasslands 

and very few trees. 

Photos courtesy of U.S. Fish 

and Wildlife Service.

Figure 2. A white-tailed prairie 

dog standing guard. Photo courtesy 

of U.S. Fish and Wildlife Service. 

Prairie dogs are social animals that 

live in large underground burrows

(figure 3). These underground burrows 

are called towns. Prairie dog towns 

are built by prairie dogs. The burrows have many 

long tunnels and rooms. The burrows have rooms used as 

nurseries, sleeping areas, and even bathrooms! When a 

female prairie dog is ready to have a baby, she goes into the 

nursery and gives birth to her baby. A baby prairie dog is 

called a “pup.” Pups are hairless and don’t open their eyes 

until they are about 6 weeks old.
74 Investi-gator • http://www.scienceinvestigator.org 

Figure 3. Prairie dog towns have many tunnels and “rooms.” 

Illustration by Samantha Bond.

Prairie dogs feed on grasses, roots, and 

seeds. In the past, ranchers thought prairie 

dogs were bad for ranch land because they 

would eat the grasses and dig holes in the 

soil (figure 4). Cows and horses might 

accidentally step into the holes and hurt 

their legs. Because some ranchers thought 

prairie dogs were a problem, some people 

worked to get rid of prairie dogs. Scientists 

believe the prairie dog population has 

declined to a small percentage of what it 

was. An effort to get rid of prairie dogs, 

however, is not the only reason the prairie 

dog population is declining. In this article, 

you will learn about another problem 

prairie dogs are facing.

Figure 4. Two prairie dogs sitting near 

the entrance of their burrow. 

Photo courtesy of the National Park Service.
Investi-gator • http://www.scienceinvestigator.org 75

Why Are Prairie Dogs Important?

Some efforts are underway to increase the populations of prairie dogs. A 

number of experts argue that prairie dogs are good for the ecosystem because 

they help aerate the soil. Aerating the soil helps more water get into the soil. 

Additionally, prairie dog scat or “poop” is high in nitrogen, which is good for the 

soil. Nitrogen is a nutrient used by plants and soil bacteria. Several predators, 

such as snakes and ferrets, rely on prairie dogs for food.

Introduction

Fleas present a problem for prairie dogs. Fleas 

are tiny, wingless insects that feed on the blood 

of other animals (figure 5). Fleas can transmit

diseases to other animals. Fleas transmit diseases 

by biting a diseased animal and carrying the 

disease to the next animal they bite. Plague is 

an infectious disease that is transmitted to other 

mammals by fleas. Prairie dogs are particularly 

susceptible to plague. 

Prairie dogs are susceptible to plague for 

two reasons. First, prairie dogs have no natural 

immunity to plague. Second, prairie dogs live 

in large colonies with complex burrow systems. 

Burrows, and the large number of animals in 

a small area, are good conditions for fleas to 

survive and reproduce. More fleas in burrows 

greatly increase the chances of prairie dogs getting 

plague. 

Plague is dangerous to all mammals. About 95 

percent of the prairie dogs living in a colony may 

die from plague if exposed to it. The high death 

rate of prairie dogs exposed to plague also affects 

animals that depend on prairie dogs for food. An 

example of an animal that depends on prairie dogs 

is the black-footed ferret (figures 6a and 6b). The 

scientists in this study were interested in figuring 

out which flea species transmit plague within a 

population of prairie dogs. The scientists also 

wanted to know if the burrows played a part in the 

plague outbreaks. 

Figure 5. Fleas can transmit 

diseases to mammals such 

as prairie dogs. Photo courtesy of 

Thinkstock.com.
76 Investi-gator • http://www.scienceinvestigator.org 

What are the questions the scientists want to answer? 

Prairie dogs have no natural immunity to the plague. Think about 

some things to which humans are not immune. Why do you think 

a strong immune system is helpful? What are some ways you 

can help protect yourself from illness? 

Figure 6a. A black-footed 

ferret looks over his 

shoulder. Photo courtesy 

of U.S. Fish and Wildlife Service. 

Figure 6b. A black-footed 

ferret peeks out of a prairie 

dog hole. Photo courtesy of 

U.S. Fish and Wildlife Service.
Investi-gator • http://www.scienceinvestigator.org 77

Ninety-five percent of the 

prairie dogs in a colony 

may die from being exposed 

to plague. If 100 prairie dogs 

are exposed to the plague, 

how many would probably 

survive?

Methods

The scientists conducted their study 

in Valles Caldera National Preserve in 

New Mexico (figure 7). The scientists 

specifically studied the Gunnison’s prairie 

dog (figures 8 and 9). The study was 

completed over 3 years from 2004-2006. 

The study areas were located in montane

grassland habitats. Montane grasslands 

are grasslands located in high elevations. 

Three grassland habitats were selected: 

1) Redondo Meadow, 2) El Cajete, and 3) 

Valle Grande (figures 10a and 10b). 

Figure 7. Valles Caldera National Preserve is located in New Mexico.

Map courtesy of Megan Friggens.
78 Investi-gator • http://www.scienceinvestigator.org 

Figures 8 and 9. Gunnison’s prairie dogs. What do 

you notice about prairie dogs that may be useful for 

where they live? Photos by Lisa Lynch, National Park Service.

Figure 10a.

El Cajete is a montane grassland. 

Montane grasslands are located at 

high elevations. Photo courtesy of www.

vallescaldera.gov.

Figure 10b. Valle Grande is the 

largest grassland in the Valles Caldera 

National Preserve. Only one road 

goes through this grassland. Look 

closely and you may be able to see the 

road in this photo. Photo courtesy of www.

vallescaldera.gov.
Investi-gator • http://www.scienceinvestigator.org 79

what is elevation?

Elevation is the distance above a reference point. When we talk about the 

elevation of land, the reference point is the level of the sea (figure 11). The 

areas in this study were between 2,460 and 2,640 meters above sea level. 

Compare this to one of the highest points of elevation in the world, Mount 

Everest, which is 8,848 meters above sea level. One of the lowest land 

elevations in the world is the area where the Dead Sea is located. The Dead 

Sea is located in the Middle East. The Dead Sea area is over 400 meters 

(over 1,300 feet) below sea level. The lowest land elevation in the United 

States is in Death Valley, California. The elevation in Death Valley is 86 meters (282 

feet) below sea level. Do research about areas around where you live and see 

how their elevations compare! 

Figure 11. Elevation is the distance above or below the level of the sea. 

Illustration by Stephanie Pfeiffer.
80 Investi-gator • http://www.scienceinvestigator.org 

The scientists examined each 

colony. During their study of 

the colonies, the scientists did 

several things. They live-trapped 

prairie dogs (figure 12). Livetrapping is a technique where 

animals are trapped for science 

research. They are not harmed 

and they are released back to their 

environment. The scientists did 

this in the spring and summer 

each year. During the first trapping session, the 

scientists marked and took global positioning 

system (GPS) coordinates of active burrows. 

GPS coordinates help scientists specifically 

locate and map areas such as prairie dog 

burrows. 

Figure 12. Scientists captured this 

Gunnison’s prairie dog for their study. The 

prairie dog is caught in a live-trap. This 

trap does not hurt the prairie dogs and 

when the scientists are finished working 

with the animals, the animals are released 

back into their habitat. Photo courtesy of Megan 

Friggens.

What is a Global Positioning System (GPS)?

A GPS is a navigation system. GPS stands for 

Global Positioning System. A GPS can tell the 

exact coordinates of where you are located on 

Earth. A GPS works by using satellites orbiting 

Earth to send information to GPS receivers. 

At any time, at least three satellites are able to 

send signals to any receiver on Earth. GPS was 

designed in 1973 by the United States military. 

The military designed GPS to help soldiers 

and military vehicles find their exact location 

anywhere in the world. Today, GPS units are 

used in a wide variety of ways. Often, cell phones 

have GPS receivers and you may even have a 

GPS device in your car that tells you directions!
Investi-gator • http://www.scienceinvestigator.org 81

The scientists identified an active burrow 

by looking for scat (or “poop”), scratch marks 

on the ground near burrow entrances, or the 

presence of a lot of flies at each burrow entrance. 

If a burrow appeared abandoned, then the 

scientists made a note of this and chose a new 

burrow close by.

The burrows and prairie dogs were examined 

for the presence of fleas. When prairie dogs were 

captured, the scientists held them over a plastic 

bin containing a felt cloth. They brushed the fur 

with a flea comb or toothbrush. After brushing, 

the fleas fell into the plastic container and onto 

the cloth. They were then collected by the 

scientists. 

The scientists collected fleas from the 

burrows. The burrows were swabbed by 

attaching a white flannel cloth to the end of 

a plumber’s snake (figure 13). The scientists 

pushed the plumber’s snake down into the 

tunnels. The scientists extended the plumber’s 

snake at least 1 meter (3.281 feet) into the 

burrow and held it there for 30 seconds. The 

scientists wiggled the flannel while down in 

the hole to imitate an animal. Sometimes the 

scientists blew on the flannel to attract fleas since 

fleas are also drawn to carbon dioxide. 

 The scientists took the plumber’s snake 

out and then placed the flannel cloth into a 

plastic bag so the fleas could be collected. 

The scientists identified and examined the 

fleas using a dissecting microscope (figure 

14). Blood samples were taken from the 

fleas to test for plague. 

Figure 13. The scientists 

used a plumber’s snake and 

other equipment to collect 

fleas. Photo courtesy of Megan 

Friggens.

Figure 14. A dissecting 

microscope is useful for 

examining very small 

animals or objects. In this 

study, the scientists used 

the dissecting microscope 

to identify what type of flea 

they had found. A dissecting 

microscope enables scientists 

to see the sample in 3-D. Photo 

by Jessica Nickelsen.
82 Investi-gator • http://www.scienceinvestigator.org 

The scientists used flannel cloth to capture fleas. Why do 

you think they used this kind of material? Do you think a slick 

surface would have been as effective at capturing the fleas? 

Why or why not? 

The scientists used a dissecting microscope to identify the 

fleas. Why do you think the microscope was used instead of 

just looking at the fleas with the naked eye to figure out what 

species they were?

Where the fleas were found Flea species Spring Summer Total

Burrows Catallagia decipiens

Oropsylla hirsuta

Oropsylla idahoensis

Oropsylla tuberculata cynomuris

Oropsylla tuberculata tuberculata

1

85

16

7

5

1

47

4

1

0

2

132

20

8

5

Gunnison’s prairie dogs Oropsylla hirsuta

Oropsylla idahoensis

Oropsylla tuberculata cynomuris

Oropsylla tuberculata tuberculata

79

5

14

3

507

23

0

2

586

28

14

5

Findings

The scientists examined 130 prairie dogs. The scientists collected 633 fleas from prairie dogs and 

167 fleas from burrows (figure 15).

Figure 15. Flea species and the number collected from burrows and Gunnison’s 

prairie dogs caught in Valles Caldera National Preserve in northern New Mexico. 
Investi-gator • http://www.scienceinvestigator.org 83

Look at Figure 15. What do you 

notice about the number of fleas 

present between the spring and 

the summer? Why do you think 

there might be this difference? 

What species of flea was 

most commonly found on the 

Gunnison’s prairie dog? In the 

burrows? Why do you think this 

might be important information for 

the scientist to know?

Do you think it is important 

for scientists to study how the 

plague affects the prairie dogs? 

Why or why not? 

Does this research have any 

importance for understanding 

how fleas might transmit 

diseases between other types 

of mammals? Why or why not? 

The scientists found that Oropsylla 

hirsuta and Oropsylla tuberculata 

tuberculata were the two primary flea species 

involved in outbreaks of plague. It had 

been reported that Oropsylla hirsuta is the 

most important flea because of how fast it 

transmits the plague among prairie dogs. 

Discussion

The scientists know that an important flea 

species for transmitting plague is Oropsylla 

hirsuta. This species was found in the largest 

numbers on the prairie dogs and in the 

burrows. This finding supports the idea that 

Oropsylla hirsuta may be the flea species that 

causes transmission of plague in prairie dogs 

in the Valles Caldera National Preserve.

The scientists believe that burrows are an 

important factor in the transmission of the 

plague. Burrows are good places for fleas to 

live and reproduce. Fleas can also easily move 

from one rodent to another in the burrows. 

Even after the plague has killed off a large 

portion of the prairie dogs in a particular 

area, fleas can live for several more months. 

Therefore, other rodent populations that come 

into the burrows may be infected by the fleas 

that are still living there. 
84 Investi-gator • http://www.scienceinvestigator.org 

Web Resources

National Geographic Prairie Dogs

http://animals.nationalgeographic.com/animals/mammals/prairie-dog/

National Zoo Prairie Dogs

http://nationalzoo.si.edu/Animals/NorthAmerica/Facts/fact-pdog.cfm

Glossary

aerate (er āt): To supply with air.

bacteria (bak tir ē ə): A group of microscopic, 

single-celled organisms that live in all 

environments.

burrow (bər ō): A hole in the ground made by 

an animal.

cay (kē): small, low-lying sandy island formed 

on the surface of a coral reef.

coordinate (kō ȯrd nət): Any of a set of 

numbers used to locate a point on a line or 

surface or in space. 

immunity (i myü nə tē): The power of the 

body to resist an infectious disease.

infectious (in fek shəs): Capable of causing 

infection.

mammal (ma məl): Any of a class of warmblooded vertebrates. This includes people and 

other animals that feed their young with milk 

from mammary glands. Their skin is usually 

more or less covered with hair. 

montane (män tān): Of, relating to, growing 

or being in the zone of moist cool upland slopes 

below tree line.

nutrient (nü trē ənt): A substance that plants, 

animals, and people need to live and grow.

plague (plāg): A serious disease that is caused 

by a bacterium, occurs or has occurred in several 

forms including bubonic plague, and is usually 

passed to human beings from infected rodents 

and especially rats by the bite of a flea or is 

passed directly from person to person.

prairie (prer ē): A large area of level or rolling 

grassland.

rodent (rō dənt): Any of an order of fairly 

small mammals that have sharp front teeth used 

for gnawing.

species (spē shēz): A class of individuals

having common attributes and designated by

a common name.

susceptible (sə sep tə bəl): Having little 

resistance.

transmit (trans mit): To transfer from one 

person, animal, or place, to another.

Accented syllables are in bold. Marks and definitions 

are from http://www.merriam-webster.com. 

If you are a Project Learning Tree 

educator, you may use Activity 26: 

Dynamic Duos or Activity 45: Web 

of Life.

Adapted from Friggens, M.M.; Parmenter, R.R.; Boyden, M; Ford, P.L.; Gage, K.; Keim, 

P. 2010. Flea abundance, diversity, and plague in Gunnison’s prairie dogs (Cynomys 

gunnisoni) and their burrows in montane grasslands in northern New Mexico. Journal of 

Wildlife Diseases. 46(2) pp:356-367. http://www.ncbi.nlm.nih.gov/pubmed/20688629.
Investi-gator • http://www.scienceinvestigator.org 85

The process you will use to answer this question is: 

1. Look at the animals and plants found in the prairie ecosystem food web. 

2. Draw arrows to connect the animals between predators and the prey they eat. 

The arrow should be drawn from the predator to the prey. In other words, the 

arrow should point to the thing that is eaten. A few connections have been drawn 

for you. Reference the “Prairie Dog Days” article if you need help figuring out 

the connections. If your teacher allows it, you can also work together with your 

classmates. Note: More than one connection can be drawn between the animals. 

3. Using the completed food web, answer the following questions:

a.What animal and/or plants are at the lowest level of the food web?

b. What do prairie dogs eat?

c. What animals feed on prairie dogs?

4. Next, cross out the prairie dog. Placing an “X” over the image represents the decline 

or removal of prairie dogs from the food web. Using the revised food web, answer 

the following questions:

a. How does the food web change when prairie dogs are removed? 

b. Will animals that feed on prairie dogs have other food options?

c. How will populations change without the prairie dogs? For example, 

will any animal or plant populations grow or shrink in numbers? 

Materials 

• “Prairie Dog Days” article

• Copies of the prairie ecosystem food web sheet 

on page 87, one for each student

• Pencil, one for each student

Time needed:

One class period

The question you 

will answer in this 

FACTivity is: 

How does the decline 

of prairie dogs affect 

the prairie food web? 

FACTivity
86 Investi-gator • http://www.scienceinvestigator.org 

Extension:

Mouse

Prairie Ecosystem Food Web EXAMPLE

FACTivity Complete an additional food web removing prairie dogs from the 

ecosystem. Discuss as a class how the rest of the ecosystem would 

be affected if prairie dogs were removed from the habitat. 
Investi-gator • http://www.scienceinvestigator.org 87

Student Name: ___________________________________________________________________________

Prairie Ecosystem Food Web
88 Investi-gator • http://www.scienceinvestigator.org 

Understanding Land 

Grants in New Mexico

Meet the Scientists!

Dr. Carol Raish 

social scientist and anthropologist 

Some of my favorite science experiences are listening to 

older people talk about the way things were in the past 

when they were young. I also love to travel to talk 

with people all over the world.

Ms. Alice McSweeney 

social science analyst

My favorite science experience is talking with ranchers to learn 

how they teach their children about the land and animals. I also love 

working on my family’s guest ranch in northern New Mexico. I 

have a Master’s degree in Range Science. Range scientists study 

rangeland plants and animals and how best to manage the 

land for these plants and animals. 

What Kind of Scientist Did This Research?

anthropologist (an(t) thrə pä lə jist): This scientist studies societies and cultures.

social science analyst: This scientist assists social scientists as they study the 

values, opinions, beliefs, attitudes, and actions of individuals and groups of people. 

social scientist: This scientist studies the values, opinions, beliefs, attitudes, and 

actions of individuals and groups of people. 
Investi-gator • http://www.scienceinvestigator.org 89

Social scientists study people. 

Anthropology (an(t) thrə pä lə jē) is one 

of the social sciences. Anthropology 

is the study of people in societies and 

cultures. Societies and cultures include 

particular groups of people. Societies 

and cultures can include groups of 

people who lived during a certain 

time and in a certain place. Societies 

and cultures can also include groups 

of people who make, for example, a 

particular type of art or music. Any 

group can have its own culture. Your 

school, for example, might have its own 

culture, different from other schools. 

Do you think a city school’s culture is 

different from a rural school’s culture 

in the United States? How might these 

cultures be different? How might they be 

similar?

Thinking About Science

Thinking About 

the Environment

Native peoples lived in Mexico 

until the Spanish invaded in the 

16th century. Mexico won its 

independence from Spain in 1821. 

Mexico once contained almost twice 

as much land as it does today (figure 

1). New Mexico, now a state in the 

United States, was once a part of 

Mexico. 

New Mexicans who lived in 

northern New Mexico during this 

time owned two types of land. 

Individual families owned a small 

piece of land for their house and a 

garden. Other large areas of land 

were shared by the community. The 

lands were granted to individuals 

and communities by the Spanish and Mexican 

governments. This ownership system was called 

land grants.

When the United States 

government gained Mexico’s 

northern territory in 1848, 

Figure 1. Before 1845, Mexico included 

what became the Republic of Texas. 

The Republic of Texas became a part 

of the United States in 1845. Between 

1845 and 1848, Mexico was made up 

of current-day Mexico, plus California, 

Nevada, Utah, Arizona, and parts of 

Colorado and New Mexico.
90 Investi-gator • http://www.scienceinvestigator.org 

it promised to respect the New Mexicans’ land 

grants. These New Mexicans became United 

States citizens in 1848 following the MexicanAmerican war. In this article, these citizens will 

be called Hispanic ranchers to reflect their ethnic 

background and how they used land. 

To keep their land grants, the Hispanic 

ranchers had to apply to the United States 

government. Most of the Hispanic ranchers were 

not awarded their land grants. One reason was 

that the Hispanic ranchers did not speak English. 

Because they did not speak English, they did not 

have the information 

to correctly apply for 

the land grants. Many 

were also cheated out of their land by dishonest 

lawyers they hired to help them. Much of the 

land lost by these Hispanic ranchers became 

national forests (figures 2, 3, and 4). In this 

article, you will learn about the descendants of 

these ranchers. You will learn how some of these 

descendants are trying to regain the land grants 

owned by their ancestors.

Figure 4. The Santa Fe National Forest. 

Figure 3.

Photo courtesy of the U.S.Forest Service.

 The Carson National Forest. 

Photo courtesy of the U.S.Forest Service.

Figure 2.

The Carson 

and Santa Fe 

National Forests 

in northern New 

Mexico. 
Investi-gator • http://www.scienceinvestigator.org 91

What is the Treaty of Guadalupe Hidalgo?

The Treaty of Guadalupe Hidalgo is the treaty that ended the MexicanAmerican War. This war was fought between the United States and Mexico 

between 1846 and 1848. The United States gained land from the treaty that 

ended the war. The United States gained California and a large area containing 

what is now Arizona, New Mexico, Nevada, Utah, and parts of Wyoming and 

Colorado (figure 5a). In the treaty, the Rio Grande was established as the 

border between Texas and Mexico (figure 5b). The United States promised 

to honor the land grants as a part of the treaty. These land grants had been 

granted to Hispanic ranchers by the Spanish and Mexican governments.

Figure 5a. The states of 

the United States that were 

gained following the MexicanAmerican War. During this 

time, these states were still 

one territory. In 1912, New 

Mexico became the 47th state 

in the United States. You 

can do research to discover 

when the other states gained 

statehood. 

Figure 5b. The Rio Grande 

forms the border between 

Texas and Mexico.

Mexico
92 Investi-gator • http://www.scienceinvestigator.org 

National forests and national grasslands are 

managed for all United States citizens. Parts 

of these forests and grasslands, however, may 

be leased to individuals and companies. Some 

individuals and companies lease public land to 

graze sheep and cattle (figure 6). They may also 

lease public land for other purposes, such as to 

mine for minerals. In New Mexico, these lands 

were once shared by the Hispanic community in 

a system of land grants. Today, some Hispanic 

people in New Mexico feel they have a right to 

regain some land. They feel this way because 

they believe the land grants were unfairly taken 

from their ancestors. Many Hispanic ranchers 

feel a connection to the lands once owned by 

their ancestors.

The scientists in this study wanted to 

understand the Forest Service’s position about 

the land grants. They were also interested in 

understanding the Hispanic descendants who 

want to regain their ancestors’ land grants. The 

scientists wondered if there was a way to resolve 

the conflict between the Hispanic ranchers and 

the Forest Service’s land grant policy.

Introduction

Figure 6. Public lands are often used by individuals and companies to graze 

sheep and cattle. Photo courtesy of Gila National Forest.
Investi-gator • http://www.scienceinvestigator.org 93

Photo, taken in 1924, courtesy of U.S. Forest Service.

How many years have passed 

since the Treaty of Guadalupe 

Hidalgo was signed in 1848?

Describe the problem 

investigated by the scientists. 

State the last sentence in the 

“Introduction” as a question. 

The scientists talked to 300 Hispanic 

ranchers who lease national forest land to graze 

cattle and sheep (figure 7). These ranchers lease 

land that their families once owned through land 

grants. To lease this land, these ranchers pay the 

Forest Service a fee every year. The scientists 

asked the ranchers questions about the historic 

land grants, current land use, and the leases. The 

scientists entered the answers into a computer. 

The scientists read the answers and comments 

and placed them into categories.

The scientists also talked with 10 people 

who work with the Forest Service. The 

scientists wanted to know if the Forest Service 

workers had suggestions that might resolve the 

conflict.

Methods 

Figure 7. A federal worker talks with 

a farmer. Photo courtesy of the Natural 

Resources Conservation Service.
94 Investi-gator • http://www.scienceinvestigator.org 

Why did the scientists talk with Hispanic ranchers as well as with 

Forest Service workers? 

Other cultures experienced something similar to this situation in 

America’s past. What other large cultural group in America lost 

lands on which their ancestors once lived? Where do many of these 

people live now? 

Some of the Hispanic ranchers said that 

the past should be left in the past. Most of the 

ranchers, however, felt anger. They felt anger 

because the land grants were not being honored 

by the United States government. Some of them 

said that by having to lease public land, they 

struggle to make a living. Others did not want to 

talk to the scientists about the land grant issue.

Some of the Hispanic ranchers said the United 

States government was trying to settle some of 

the land grants. Others said that there may not be 

a way to resolve the injustices of the past. Many 

people wished the United States government 

would admit its role in these injustices. Most of 

the Hispanic ranchers felt their ancestors had 

been wronged by the United States government.

The Forest Service workers told the scientists 

that they have no choice but to defend the United 

States government’s ownership of public lands. 

The official viewpoint of the government is that 

the land grants were properly managed following 

the Mexican-American war. Forest Service 

workers had different opinions on whether this 

was true. Forest Service workers suggested some 

actions to help resolve the land grant issue:

• Teach Forest Service workers about Hispanic 

ranchers’ history, culture, and way of life.

• Include Hispanic ranchers on committees that 

plan future use of public lands.

• Develop agreements with Hispanic ranchers 

about collecting firewood from public lands.

• Develop agreements with Hispanic ranchers 

about their access to and use of public lands.

• Appoint one Forest Service worker to work 

directly with Hispanic ranchers.

• Build trust between Hispanic ranchers 

and Forest Service workers by improving 

communication.

Forest Service workers did not agree with each 

other about the land grant issue. All agreed, 

however, that the issue can only be resolved 

by the United States Congress. Congress is the 

body that makes United States laws. Only a new 

law can change the way Forest Service workers 

manage the national forests in New Mexico.

Findings
Investi-gator • http://www.scienceinvestigator.org 95

In the 1960s, Hispanic ranchers began to 

protest the loss of their ancestors’ land grants. 

Now, in the early 21st century, the question of 

land grants has not yet been resolved. If the 

United States Congress considers the question 

of land grants in northern New Mexico, the 

issue may finally be resolved. Until then, the 

Forest Service will continue to manage the 

lands as national forests for all United States 

citizens. 

How do Hispanic ranchers and Forest Service workers feel about 

resolving the land grant issue? How do you know?

Should the suggestions made by Forest Service workers be tried? Why? 

Have you ever heard people say that better communication will help 

resolve a problem? Is this true? Why or why not?

Do you think the United States Congress should consider the land 

grant issue in northern New Mexico? Why or why not? 

Many mistakes were made over 100 years ago in places all over 

the world. Because these mistakes were made before anyone alive 

today was born, no one living today is responsible. Even so, the 

descendants of people who were wronged feel the wrongs should 

be made right. How do you feel about this problem? Hold a class 

discussion about both sides of this issue. Identify other examples.

Discussion
96 Investi-gator • http://www.scienceinvestigator.org 

Adapted from Raish, C.; McSweeney, A.M. 2008. Land grants and 

the Forest Service. Natural Resources Journal. 48(4):1039-1055. 

http://www.fs.fed.us/rm/pubs_other/rmrs_2008_raish_c002.pdf.

If you are a Project Learning Tree educator, you may use 

Activity 32: A Forest of Many Uses, Activity 50: 400-Acre 

Wood, or Activity 56: We Can Work On It.

Glossary

ancestor (an ses tər): One from whom a 

person, group, or species comes from.

descendant (di sen dənt): Coming from an 

ancestor or source.

grassland (gras land): Land on which the 

most common plants are grasses. 

injustice (in jəs təs): An unjust or unfair act.

lease (lēs): Land that someone can use for a set 

period of time, that usually comes at some cost.

national forest (nash nəl fȯr əst): A large 

area of public land that is forested and taken care 

of by government. It is available for all people to 

use and enjoy.

native (nā tiv): Belonging to a particular place 

by birth.

official (ō fi shəl): The rules of people in a 

public office. 

policy (pä lə sē): A method of action to guide 

and determine decisions. 

public land (pub lik land): Land that is owned 

by the people as a whole. 

regain (re gān): To get back.

resolve (ri zälv): To find an answer or solution.

rural (ru̇ r əl): Something related to the 

country, country people or life, or agriculture.

scarce (skers): Not plentiful.

Accented syllables are in bold. Marks and definitions 

are from http://www.merriam-webster.com. 

Photo by Forest Service- Southwestern Region. 
Investi-gator • http://www.scienceinvestigator.org 97

The method you will use to answer this question is: 

1. First, you will read the following background information:

Botswana is a country located in southern Africa. The Kalahari Desert is 

located in southern Botswana. For tens of thousands of years, the San Tribes, or Bushman, 

have lived in the Kalahari Desert. The Kalahari Desert is also home to several Botswana 

National Game Reserves. The Botswana government wanted the San Tribes to move out 

of the Kalahari Desert. The government said it wanted the San Tribes to move because the 

tribes were killing too many animals for food. The San Tribes said the government wanted 

them to move because diamonds had been discovered underground. 

In 2002, the Botswana government moved the San Tribes from the Kalahari Desert 

into places similar to refugee camps. The San Tribes went to court to win the right to 

return to the Kalahari Desert. In 2006, the San Tribes won the court case and returned to 

the desert. The Botswana government then kept the San Tribes from drilling or using any 

existing water wells. Because the Kalahari is a desert, water is scarce. The San Tribes 

appealed the court ruling that prohibited them from drilling or using water wells. In 2010, 

a judge upheld the government’s right to prohibit the San Tribes from using or drilling 

water wells. The San Tribes then appealed to a higher court. On January 27, 2011, an 

appeals court overturned the earlier ruling. The appeals court said the San Tribes could use 

existing water wells and drill new water wells. 

2. You will use the graphic organizer in the next section. Compare and contrast the situation 

faced by the ancestors of the Hispanic ranchers in “The Lands of Time” with the 

experience of the San Tribes. Use the spaces to write what you know about each of these 

situations. Use complete sentences, proper grammar, and correct punctuation.

Materials 

• “The Lands of Time” Investi-gator article

Time needed:

One class period

The question you 

will answer in this 

FACTivity is: 

How is the current 

situation in the 

southern African 

nation of Botswana 

similar to and 

different from the 

historic land grant 

situation in New 

Mexico?

FACTivity
98 Investi-gator • http://www.scienceinvestigator.org 

GROUP

Hispanic Ranchers San Tribes

Describe the land area where 

each group lived.

Describe the background of 

the people involved in each 

situation.

Which national government 

was involved in each situation?

What kind of public land was 

created out of each group’s 

homelands?

What happened to cause 

the government to take each 

group’s land?

What legal options were 

available to each group?

How successful with their legal 

options was each group? What 

might be some reasons? 

Write one sentence identifying 

at least one similarity between 

these two situations.

Write one sentence identifying 

at least one difference between 

these two situations. 

Your teacher will lead a class discussion about these two situations. 

As a class, discuss what you know about similar situations in history. 
Investi-gator • http://www.scienceinvestigator.org 99

Web Resources

Santa Fe National Forest 

http://www.fs.usda.gov/santafe/

Carson National Forest

http://www.fs.usda.gov/carson

Historical Events That Affected Northern New Mexico

http://shelledy.mesa.k12.co.us/staff/computerlab/Western_CO_

History_Mexican_American_War.htm

“The Lands of Time” is taken from this saying by 

David Lawrence Dewey: “Through the sands of 

time...the written word has changed the course of 

history, inspired many to fight for their beliefs, and 

most importantly...elevated mankind to a higher 

understanding of man’s inhumanity to mankind.” In 

ancient times, time was measured by an hourglass, 

through which sand would fall over a specified 

amount of time (figure 8).

Figure 8. In this hourglass, the sand falls 

through the small hole in 30 minutes.
100 Investi-gator • http://www.scienceinvestigator.org 

Southwestern United States Investi-gator

Explain or write what you see in each 

photo and how the photo relates to the 

article in which it was found. If you write, 

be sure to write at least three sentences 

for each photo using proper sentence 

structure, grammar, and punctuation.

Photo Challenge

Photo courtesy of Dr. Hugo Magaña. 

Photo by Rod Replogle, Forest Service.

Photo courtesy of Jim Rorabaugh, U.S. Fish and Wildlife Service.

Photo courtesy of John Adams, University of Arizona, Biosphere 2.

Photo by Lisa Lynch, National Park Service.
Investi-gator • http://www.scienceinvestigator.org 101

Southwestern United States Investi-gator

Crossword Puzzle
102 Investi-gator • http://www.scienceinvestigator.org 

Where Am I in the Southwestern United States?

Map Activity

Map 1

Map 2

Your Compass

Map 3

Map 4

Map 5
Investi-gator • http://www.scienceinvestigator.org 103

Five Southwestern maps from this journal are shown on the left. Photos and illustrations 

found in the articles are shown below. Inside of the box on the left hand page, draw a 

compass correctly showing the directions of north, south, east, and west. Then, write the 

map number that matches each photo. A map may match more than one photo.

Photo courtesy of Gila National Forest.

Illustration by Stephanie Pfeiffer.

Using the graphic organizer on the following page, explain the relationship between the photo or 

illustration and its map. Use complete sentences, proper grammar, and correct punctuation.

Map # _______ Map # _______

Map # _______

Map # _______

Map # _______

Map # _______

Map # _______

Map # _______

Map # _______

Photo by Babs McDonald.

Photo courtesy of 

Thinkstock.com.

Photo courtesy of Thinkstock.com.

Photo by Chuck Murphy and http://www.boywithcamera.com.

Photo courtesy of Andrew Kuhn, National Park Service.

Photos by Lisa Lynch, National Park Service.

Illustration 

by Stephanie 

Pfeiffer.
104 Investi-gator • http://www.scienceinvestigator.org 

Where Am I in the Southwestern United States?

Photo or Illustration The Relationship Between the Photo 

or Illustration and the Map is...

Peregrine falcon

Black-chinned 

hummingbird

Cattle

Flea

Intermittent stream

Gunnison’s prairie dog

Rio Grande 

silvery minnow

Rio Grande

Feeding fish
Investi-gator • http://www.scienceinvestigator.org 105

National Science Education Standards for the Animals and Ecosystems of 

the Southwestern United States Investi-gator

Journal Article

That’s a 

Humdinger! 

By the 

Light of 

the Silvery 

Minnow

Wild Ways Streaming 

Live

Prairie Dog 

Days

The Lands of 

Time

Science as Inquiry 

Abilities Necessary To Do 

Scientific Inquiry

Understanding About 

Scientific Inquiry

Life Science

Structure & Function in 

Living Systems

Regulation & Behavior

Populations & Ecosystems

Diversity & Adaptations of 

Organisms

Earth Science

Structure of Earth System

Science & Technology

Understanding About 

Science & Technology

Science in Personal & 

Social Perspectives

Populations, Resources, and 

Environments

Risks & Benefits

Science & Technology in Society

History & Nature of Science

Science as a Human Endeavor

Nature of Science

History of Science
106 Investi-gator • http://www.scienceinvestigator.org 

National Curriculum Standards for Social Studies for the Animals and 

Ecosystems of the Southwestern United States Investi-gator

Journal Article

That’s a 

Humdinger! 

By the 

Light of 

the Silvery 

Minnow

Wild Ways Streaming 

Live

Prairie Dog 

Days

The Lands 

of Time

Culture

Time, Continuity, and Change

People, Places, and 

Environments

Individuals, Groups, and 

Institutions

Power, Authority, and 

Governance

Science, Technology, and Society

Global Connections

Civic Ideals and Practices

 

Photo by Forest Service- Southwestern Region. 
Investi-gator • http://www.scienceinvestigator.org 107

What is the Forest Service?

What is the Rocky Mountain Research Station?

What Is the Cradle of Forestry in America 

Interpretive Association? 

What is the Southwestern Region?

For more information, visit http://www.fs.fed.us.

For more about the Rocky Mountain Research Station visit http://www.fs.fed.us/rmrs.

For more about the Southwestern Region of the Forest Service visit http://www.fs.usda.gov/r3.

The Cradle of Forestry in America Interpretive Association (CFAIA) is a 501(c)3 nonprofit organization based in 

Brevard, North Carolina. CFAIA strives to help people better understand ecology through recreation and education 

opportunities. Their projects include:

• Campground and recreation area management

• Educational programs and services, including Natural Inquirer, Investi-gator, and Nature-Oriented Parenting

• Sales of forest-related gifts and educational materials

• Workshops, newsletters, and publications

• Partnership with the Forest Service to provide programming at the Cradle of Forestry Historic Site

For more about the CFAIA visit http://www.cfaia.org.

The Forest Service is a part of the U.S. 

Department of Agriculture. It is made up of 

thousands of people who care for the Nation’s 

forest and grassland. The Forest Service manages over 150 

national forests and almost 20 national grasslands. These 

are large areas of trees, streams, and grasslands. National 

forests are similar in some ways to national parks. Both are 

public lands, meaning that they are owned by the public 

and managed for the public’s use and benefit. Both national 

forests and national parks provide clean water and homes 

for the animals that live in the wild and places for people to 

do fun things in the outdoors. National forests also provide 

resources for people to use, such as trees for lumber, 

minerals, and plants used for medicines. Some people in the 

Forest Service are scientists whose work is presented in the 

journal. Forest Service scientists work to solve problems 

and provide new information about natural resources so 

that we can make sure our natural environment is healthy, 

now and into the future.

The Rocky Mountain Research Station is one of five 

Forest Service Research and Development stations. It 

maintains 12 research laboratories within its 12-state 

territory, encompassing the Great Basin, the Southwest, the 

Rocky Mountains and parts of the Great Plains. The Station 

employs close to 400 permanent full-time employees, 

including almost 100 research scientists.

The Station works to provide options on the sustainable 

use and appreciation of forests and rangelands by producing 

quality science, quality service, and quality relationships 

with stakeholders around the Greater Rocky Mountain 

region. 

The Southwestern Region of the Forest Service includes 

12 national forests and 3 national grasslands in Arizona, 

New Mexico, western Oklahoma, and the Texas Panhandle. 

Marked by alpine peaks, colorful mesas, and dramatic 

canyons, this sunbaked region also features wild whitewater 

rivers and clear mountain streams. Renowned for its 

Indian-Hispanic-Anglo culture, the area’s unique heritage 

is visible in its wealth of prehistoric and historic sites, and 

in the lives of many of its residents who still celebrate the 

ways of centuries past. 

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable sex, 

marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of and individuals’ income is derived from any 

public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large 

print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 

1400 Independence Avenue, S.W. Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.

The use of trade or firm names in this publication is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service.
Investi-gator Review Board

For additional information, please visit these Web sites:

Forest Service

http://www.fs.fed.us

Investi-gator

http://www.scienceinvestigator.org

Natural Inquirer

http://naturalinquirer.org

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http://www.fs.usda.gov/conservationeducation

Forest Service Southwestern Region 

http://www.fs.usda.gov/r3/

Forest Service Rocky Mountain Research Station

http://www.fs.fed.us/rmrs/

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http://discovertheforest.org/

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Fall 2013