U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2004-3029

March 2004

Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin

Predicting and Mapping Bird Abundances 

History

Bird enthusiasts and ornithologists 

are working together to conserve 

the diversity of birds across North 

America by focusing on habitat 

conservation. To identify the best 

locations for conservation action, 

scientists are interested in predicting 

where bird species of conservation 

concern can be found. These species 

have been identifi ed by the U.S. 

Fish and Wildlife Service (FWS) as 

being at risk of population declines. 

The benefi ts of research addressing 

regional and national migratory 

bird conservation are compelling 

and are among the core research 

responsibilities of USGS. Some 

of the most common questions that 

managers ask include the following:

• Where on the landscape can we 

expect to find species of conservation concern? 

• How many individuals of the 

species exist and where are the 

population “hot spots” or areas 

where the population is greatest?

• What conservation actions will 

benefit the species?

• How will threats such as urban 

sprawl, timber harvest, mineral 

extraction, or climate change 

affect bird populations?

What USGS has done 

Scientists at the USGS Upper 

Midwest Environmental Sciences 

Center (UMESC) have developed 

statistical models for predicting and 

mapping habitat associations across 

entire ecoregions for species at risk 

like the cerulean warbler (Dendroica 

cerulea). To build the models, we 

use data from the North American 

Breeding Bird Survey, a continental 

USGS program for monitoring the 

status and trends of North American 

Predicted relative abundance of cerulean warblers in the Prairie Hardwood Transition Ecoregion, 

a conservation region identified for bird management, are shown above. The model predicts that 

Allegan and Barry State Game Areas and the Department of Defense Custer Reserve Forces 

Training Area in Michigan have high abundances of cerulean warblers. Managers can use this 

information to monitor cerulean warbler populations and develop forest bird conservation partnerships for this region.
bird populations. We link the 

Breeding Bird Survey data with 

digital maps of land cover, elevation, 

soil, moisture, and climate and then 

derive bird-habitat models. These 

models describe the complex set of 

environmental conditions that support 

populations of a particular species. 

Finally, from these models we create 

maps that depict where a species is 

likely to be found within a state or 

region and estimates of how many 

individuals are likely to be there. 

Result

Resource managers can use the 

models and maps to identify and 

prioritize habitats for conservation 

actions and future monitoring. For 

example, the maps help identify 

potential high-quality habitats in 

proximity to existing U.S. Fish and 

Wildlife Service (FWS) refuges and 

other wildlife management areas. 

Conservation partners can focus 

on these areas to restore habitats 

or protect important species. The 

models are also used to identify new 

potential management areas. 

The Upper Midwest Environmental Sciences Center is developing maps of bird distribution and 

abundance for four bird conservation regions in eastern North America. These bird conservation 

regions were defined on the basis of similar topography, vegetation, and climate, which determine 

the bird species found in a region.

Statistical models are used to predict and map the relative abundance of species like the redhead woodpecker (Melanerpes erythrocephalus), grasshopper sparrow (Ammodramus savannarum) and 

the wood thrush (Hylocichla mustelina) across large areas such as Bird Conservation Regions. 

This work is described at the following Web site: http://www.umesc.usgs.gov/terrestrial/

migratory_birds/5004911_bird_conservation.html

Resource managers may use future 

extensions of this habitat modeling 

as a basis for evaluating threats to 

breeding habitats. Any threats that 

can be mapped (e.g., urban sprawl, 

timber harvest, mineral extraction, 

acid rain, climate change) can be 

compared with maps depicting 

locations of bird concentrations to 

judge the magnitude of threats to the 

species. We are currently exploring 

ways to use the models and maps as 

a basis for estimating total population 

size for bird species of conservation 

concern.

For more information, contact

Melinda Knutson

608.781.6339

mknutson@usgs.gov

Wayne Thogmartin

608.781.6309

wthogmartin@usgs.gov

USGS Upper Midwest Environmental 

Sciences Center

2630 Fanta Reed Road

La Crosse, WI 54603

http://www.umesc.usgs.gov/

Red-head woodpecker photo 

by Brian Collins.

Grasshopper sparrow 

photo by Mike McDowell.

Wood thrush.