U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2014–3071

March 2015

FORT COLLINS SCIENCE CENTER

Trust Species and Habitats Branch

Using the Innovative Approaches of Today to Conserve Biodiversity for Tomorrow

Species Conservation

Large scale changes are occurring to our natural landscapes, 

often resulting in changes to the distribution and abundance of 

species living within these landscapes. Populations of many species affected by these natural or anthropogenic changes require 

focused management to ensure their conservation and sometimes 

recovery from the brink of extinction. For many of these species, 

limited information exists about their life history, status, and distribution, or how changes in their abundance or distribution alter 

ecosystem processes, productivity, or structure. TSH scientists 

develop innovative tools, techniques, and research to understand 

species’ distribution, interactions, condition, and conservation 

requirements. U.S. Department of the Interior, State agencies and 

others use the results of our work to better understand species’ 

response to environmental change, inform conservation and 

management needs, and conserve biodiversity and ecosystem 

function across our landscapes.

Molecular Genetics

The use of molecular genetics tools has become increasingly important in addressing wildlife conservation issues. TSH 

geneticists use genetic information to augment studies of population dynamics and population viability, investigate population 

structure and gene flow, estimate population size and survival 

rates, and document genetic diversity. Newer and more comprehensive genomic methods are increasingly being used to: 

study the structure, function, and expression of genes and their 

response to environmental stressors; elucidate how geographical and environmental features structure genetic processes 

such as gene flow, genetic drift, and selection; identify, track, 

and make predictions regarding emerging infectious diseases; 

and monitor and predict the impacts of invasive species and 

contaminants on wildlife and ecosystems. 

Photograph by Dean Biggins, USGS.

Capabilities

Some of the biggest challenges facing wildlife today are changes to their environment 

from both natural and anthropogenic causes. Natural resource managers, planners, policy 

makers, industry and private landowners must make informed decisions and policies regarding management, conservation, and restoration of species, habitats, and ecosystem function 

in response to these changes. Specific needs include (1) a better understanding of population 

status and trends; (2) understanding of species’ habitat needs and roles in supporting ecosystem functions; (3) the ability to assess species’ responses to environmental changes and 

predict future responses; and (4) the development of innovative techniques and tools to better 

understand, minimize or prevent any unintended consequences of environmental change.

The Trust Species and Habitats (TSH) Branch of the Fort Collins Science Center (FORT) 

includes a diverse group of scientists encompassing both traditional and specialized expertise in wildlife biology, ecosystem ecology, quantitative ecology, disease ecology, molecular 

genetics, and stable isotope geochemistry. Using our expertise and collaborating with others 

around the world, our goal is to provide the information, tools, and technologies that our 

partners need to support conservation, management, and restoration of terrestrial vertebrate 

populations, habitats, and ecosystem function in a changing world. Photograph by Kenneth Ingham.
Photograph by Paul Cryan, USGS.

Ecology of Wildlife Disease

The United States is undergoing ecological change that is 

increasing the interface between wildlife, humans, and disease. 

Such changes are resulting in unpredictable shifts in the balances 

of disease cycles in natural hosts and humans, with consequences 

to many imperiled species. In addition to population declines, the 

loss of wildlife from disease contributes to a corresponding decline 

in ecosystem services that benefit human health and economies. 

TSH scientists collaborate with researchers and resource managers around the world to gain better scientific understanding of the 

ecological factors involved in the transmission and epidemiology of 

infectious diseases in wildlife, as well as contributing to the development of tools and techniques to help understand and manage 

disease in wildlife populations.

Ecological Applications of Stable Isotopes

Stable isotope geochemistry represents a powerful tool for 

better understanding biogeochemical cycles, species’ distributions, contaminant cycling, food webs, and ecosystem structure. 

Using stable isotopes, TSH scientists are able to capitalize on 

two essential attributes. First, isotopic ratios in an organism’s 

tissue reflect the isotopic ratios of what it eats or grows in, and 

second, local isotopic ratios vary spatially across the face of the 

earth. Combining this knowledge, our scientists can make inferences into the dietary habits and migration pathways of birds, 

mammals and fish, as well as contaminant cycling and accumulation in species and their habitats. There is a growing need for 

such information and stable isotopes offer a new approach to 

integrate earth and life sciences in the context of conservation 

and environmental change.

Photograph by Marcy Marot, USGS.

Biometrics

Mathematical and statistical methods used to analyze biological data are powerful research tools that play 

several important roles in conceptualizing and understanding the structure and dynamics of ecological systems. 

Through the development of specialized and sophisticated quantitative tools and models, the complex nature of 

data arising from studies of ecological systems can be understood. Scientists in the TSH branch conduct research 

to develop and evaluate mathematical and statistical tools and models that abstract and accommodate the unique 

characteristics of ecological systems and data, while also allowing for maximum extraction of information about 

those systems. This research is critical for improving the information gained from time-consuming, logistically 

difficult, and resource-intense field studies.

Photograph by U.S. Fish and Wildlife Service.
Landscape Genetics of Sage Grouse

Greater and Gunnison sage-grouse populations are species considered for listing under the Endangered Species Act of 

1973. Loss and fragmentation of sagebrush habitats are among the 

primary causes of decline in these species. A fundamental need for 

species conservation is to identify and subsequently maintain a set 

of connected populations. Landscape genetics combines the fields 

of population genetics and landscape ecology to investigate how 

landscape and environmental features affect connectivity, gene 

flow, population structure, and local adaptation. TSH geneticists, 

in collaboration with other USGS scientists, Federal, State, and 

local agencies, and academia, are using genetic data in conjunction 

with landscape data (for example, habitat, roads, energy development, and elevation) to identify landscape features that function as 

barriers to movement for both Greater and Gunnison sage-grouse. 

These studies will help define biologically meaningful populations, provide information on levels of connectivity among 

populations, and define characteristics of barriers (including geographic distance, topographic features, and anthropogenic 

land uses) that affect dispersal and genetic exchange. Managers will be able to apply this understanding to focus conservation 

efforts in areas that will maximize benefits to sage-grouse populations.

Ecology of Plague

In North America, the flea transmitted plague bacterium (Yersinia pestis) has colonized and altered native animal 

communities and ecosystems since its invasion a little more than a century ago. Many species have suffered adverse consequences from plague, perhaps none more than the endangered black-footed ferret. Plague has established within the ranges 

of all North American prairie dog species, which collectively serve as the sole habitat and predominant prey base for the 

endangered black-footed ferret. This disease causes periodic and 

sometimes dramatic die-offs of both prairie dogs and ferrets. Plague 

also threatens the recovery of the threatened Utah prairie dog and is 

suspected of contributing to declines in other species of conservation 

concern. TSH scientists are conducting research on various aspects 

of plague ecology and management including: (1) treatment-control 

studies using vaccines and insecticides to examine effects of enzootic 

plague on survival rates and other population parameters in various 

animal communities, (2) field testing the efficacy of a bait-delivered 

vaccine for prairie dogs, (3) investigating factors involved in plague 

persistence in the environment, and (4) evaluating potential development of insecticide resistance in fleas. Findings from this research 

will provide resource managers a better understanding of plague and 

new tools for managing this disease in wildlife. Photograph by Tonie Rocke, USGS.

Photograph by Gerrit Vyn.

Selected Projects

Bat Fatalities at Wind Turbines—Investigating the Causes and Consequences

Wind energy is one of the fastest-growing industries in the world and represents an important step toward reducing 

dependence on nonrenewable sources of power. However, unprecedented numbers of tree-roosting bats are dying at wind 

turbines on multiple continents, raising concerns about the well-being of these animals. While causes of bat fatalities at wind 

turbines remain unknown, potential clues can be found in the patterns of fatalities. TSH scientists, in collaboration with other 

U.S. Geological Survey (USGS) science centers as well as partners from Federal, State, and non-governmental organizations, 

are using these clues to focus research efforts. Investigations are underway to (1) better identify the seasonal distributions, 

habitat needs, and migration patterns of species showing greatest susceptibility, (2) assess the potential roles of mating and 

feeding behaviors in turbine collisions, (3) develop new video-based methods for studying and monitoring bats flying around 

wind turbines at night, and (4) test whether bats are attracted to turbines. Findings from these studies are leading us toward 

new ways of monitoring and possibly avoiding bat fatalities at wind turbines. Photograph by Paul Cryan, USGS.
Using Quantile Regression to Investigate Ecological Limiting Factors

Unexplained heterogeneity in statistical models of animal responses to 

their physical environment is reasonable to expect because the measured habitat 

resources are a constraint on—but not the sole determinant of—abundance, survival, fecundity, or fitness. The ecological understanding and reliability of management predictions based on animal habitat models can be improved by shifting focus 

from estimating expected values (means) of responses to estimating intervals of 

responses associated with multiple percentiles of a distribution. TSH scientists have 

refined quantile regression to provide novel insights on trout densities in stream 

habitat, allometric growth of fish to assess body condition, monitoring habitat management objectives at National Wildlife Refuges, and evaluating changes in streamwater quality over 40 years. Additional refinements include modifying quantile 

regression for small counts to evaluate effects of climate, demographic characteristics of parents, and landscape habitat on California 

spotted owl fledglings produced on territories over 20 years on the Lassen National Forest. Quantile regression can provide managers 

with modeled relationships that more realistically reflect the variation in animal responses observed in their physical environments.

Staff

Branch Chief: Patricia Stevens, M.S., Supervisory Wildlife

 Biologist, stevensp@usgs.gov

Biggins, Dean, Ph.D., Wildlife Research Biologist,

 bigginsd@usgs.gov

Cade, Brian, Ph.D., Research Statistician (Biology),

 cadeb@usgs.gov

Cornman, Robert, Ph.D., Bioinformaticist,

 rcornman@usgs.gov

Cryan, Paul, Ph.D., Research Biologist, cryanp@usgs.gov

Eads, David, Ph.D., Post Doctoral Research Fellow, Colorado

 State University, daeads@lamar.colostate.edu

Ellison, Laura, M.S., Ecologist, ellisonl@usgs.gov

Fike, Jennifer, M.S., Geneticist, fikej@usgs.gov

Langin, Kathryn, Ph.D., Research Ecologist, Post-Doctoral

 Mendenhall Fellow, klangin@usgs.gov

Makiejus, Julia, Youth Program Intern, jmakiejus@usgs.gov

Oh, Kevin, Ph.D., Research Ecologist, Post-Doctoral 

 Mendenhall Fellow, koh@usgs.gov

O’Shea, Tom, Ph.D. Emeritus Scientist, osheat@usgs.gov

Susan, Tracy, Science Technician,

 tracy.susan@ram.colostate.edu

Oyler-McCance, Sara, Ph.D., Research Geneticist, 

 sara_oyler-mccance@usgs.gov

Foraging Ecology Using Stable Isotopes

Understanding species habitat requirements is incomplete without insight into nutrition, 

including various aspects of foraging ecology. Traditional diet studies can be challenging because 

of logistics, issues related to resource availability, and observations are often short-term in nature 

based on gut contents or scat. Additionally, perturbations such as species introductions, habitat 

degradation, pollution, and climate change can drastically alter the availability and quality of 

dietary resources. Stable isotope techniques offer a useful tool for gaining longer-term insight 

into the dietary habits for a variety of wildlife species. In collaboration with other USGS scientists, Federal and State agencies, and university researchers, TSH scientists are using stable isotopes to: (1) understand the foraging habits of polar bears, providing context from which future 

changes because of habitat loss can be inferred; (2) investigate nutritional stress as the cause 

of population decline in Stellar sea lions; (3) assess the effects of a gillnet ban on bottlenose 

dolphin, (4) reconstruct aquatic food web pathways before and after exotic species invasions; 

(5) determine the arrival time on arctic breeding grounds of a long-distance migratory shorebird 

based on a shift in diet; and (6) clarify the role of marine-derived nutrients to juvenile salmon. 

Findings from this work are providing valuable insight into the foraging ecology of species of 

management or conservation concern. 

Photograph by Alan Franklin, U.S. Department of Agriculture.

Photograph by U.S. Fish and Wildlife Service.

Ruth, Janet, Ph.D., Research Ecologist, janet_ruth@usgs.gov

Stanley, Tom, Ph.D., Research Wildlife Biologist,

 stanleyt@usgs.gov

Stricker, Craig, Ph.D., Research Biologist, cstricker@usgs.gov

Taylor, Dan, B.S., Science Technician,

 drtaylor@rams.colorado.edu

Valdez, Ernest, Ph.D., Research Wildlife Biologist, 

 ernie@usgs.gov

Zimmerman, Shawna, Ph.D. candidate, Colorado State 

 University, szimmerman@usgs.gov

And a continuing team of short- and long-term contractors, 

work-study students, student contractors, and a large cadre of 

volunteers, all of whom are essential to the accomplishments 

and productivity of our branch. 

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20143071

Contact Information

Patricia Stevens, M.S., Branch Chief

U.S. Geological Survey 

Fort Collins Science Center

2150 Centre Avenue, Building C

Fort Collins, Colorado 80526-8118

Tel. 970.226.9499 Fax 970.226.9230

stevensp@usgs.gov

Learn more about FORT science, 

products, and resources at

 http://www.fort.usgs.gov

Trust Species and Habitats Branch 

Web site: 

 http://www.fort.usgs.gov/TSH/