Office of External Affairs
Mountain-Prairie Region


U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

For Immediate Release

November 6, 2012


Neal Niemuth 701.355.8542;
Leith Edgar 303.236.4588;                             

Habitat & Population Evaluation Teams Complete Analysis of 25th Year of Four-Square-Mile Survey Data


The U.S. Fish and Wildlife Service's (Service) Habitat and Population Evaluation Teams (HAPET) recently completed analysis of the 25th year of Four-Square-Mile Survey data collected in the Prairie Pothole Region.

Begun in 1987 by researchers at the Northern Prairie Wildlife Research Center, the Four-Square-Mile Survey was originally developed to assess waterfowl use of Service and private lands. The HAPET offices, which have conducted the survey since 1990, presently sample 704 survey plots annually. Each plot covers four square miles, which is the home range of a breeding female mallard. Waterfowl are surveyed on 5,933 wetlands, and water levels are assessed on 70,021 wetlands with a total area of 194,106 acres.

Data from this survey are used to target easement acquisition, evaluate effects of conservation programs, inform Farm Bill programs, monitor landscape change, assess wetland dynamics, guide evaluation of the effects of wind energy development on waterfowl, and provide baseline data used in development of spatially explicit models for waterfowl and non-game birds. The Four-Square-Mile Survey and its products were models for the concept of Strategic Habitat Conservation, which was recently adopted by the Service.

One of the most recognizable products developed from Four-Square-Mile Survey data is the waterfowl breeding pair accessibility map, also known as the Thunderstorm Map. This decision-support tool provides a spatially-explicit, scientific foundation for targeting millions of conservation dollars annually by the Service and partners for easement acquisition, Partners for Fish and Wildlife private land projects, and other conservation actions for breeding waterfowl.

Another major benefit provided by the Four-Square-Mile Survey is the HAPET offices' extensive records of annual water conditions for 70,000 wetlands, which include the second driest drought of the 20th century and the wettest period in the past 130, possibly 500, years. These data are being incorporated into a variety of projects related to climate change in the Prairie Pothole Region, including determination of mechanisms influencing wetland water levels, improvement of wetland monitoring programs, and modeling of response to climate change by wetland-dependent birds.

For public-domain graphics of products derived from the Four-Square-Mile Survey data set, please, please visit the following flickr gallery:

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals, and commitment to public service.

For more information on our work and the people who make it happen, visit Connect with our Facebook page at, follow our tweets at, watch our YouTube Channel at and download photos from our Flickr page at

 - FWS -