They're abundant in this area, but hard to count reliably. We outline a procedure for estimating the population sizes so that we can determine whether they're increasing or dwindling. We must both listen for their calls and visually confirm them.
We removed non-native fish from a section of the river and the endangered native species humpback chub increased in abundance. But it is not yet clear that decreased competition explains the rebound in population.
Polar bears are endangered by reduction in Arctic sea-ice concentration and by reduction in their supply of prey for food. Models shown here indicate anticipated effects on polar bear populations of several climate change scenarios.
Three themes of ongoing research: forecasting polar bear and walrus population response to changing marine ecosystems; measuring wildlife population changes in the Arctic coastal plain, and wildlife communities in the boreal-Arctic transition zone.
Loss of sea ice has increased ocean wave action, changing coastal habitats. For some geese this has been a positive change, increasing the amount of coastal area that supports vegetation the geese feed on.
Declines in fish and wildlife populations, water-quality issues, and changes in coastal habitats have prompted this USGS study of the region's nearshore life and environment. Includes links to data from published reports.
Population size, foaling, deaths, age structure, sex ratio, age-specific survival rates, and more over a 14 year time span. This information will help land and wildlife managers find the best maintenance and conservation strategies.
Recent physical changes over time, including trends toward earlier snowmelt runoff, decreasing river ice, and increasing spring water temperatures, may affect salmon populations; we want to know how important these effects are.
North American Breeding Bird Survey (BBS) is a cooperative program that monitors the status and trends of North American bird populations. Includes files of results, analyses, route collection maps and raw data.
Report on the Sirenia Project use of a radio tracking study to determine manatee movement patterns and habitat to develop ecological models to understand and predict the effects of hydrologic restoration on manatees in Southwest Florida.
One of the greatest challenges for conserving grassland, prairie scrub, and shrub-steppe ecosystems is maintaining prairie dog populations across the landscape. Of the four species of prairie dogs found in the United States, the Utah prairie dog (Cynomys
Changes in the channel of the river to support commercial use have affected river-corridor habitats and diminished populations of native fish and wildlife; this study seeks to understand those changes to help local resource managers.
The U.S. Geological Survey established a sediment trap in the northern Gulf of Mexico to collect time-series data on the flux and assemblage composition of live planktic foraminifers. This report provides an update of the 2008 time-series data to include
Description of the Status and Trends program, which monitors the abundance, distribution, productivity, and health of the Nation's living resources, detecting and evaluating changes in these variables over time.
Report on the population of northern pintails between 1979 and the 1990s in Sacramento Valley, California, including methods of study including radio telemetry, causes of mortality, morphometrics, survival rates, and management implications.
Complex interactions among hydrologic events initiated by people and the behaviors and characteristics of animal species (both native and introduced) lead to important scientific and management problems.
Report on the captive breeding program at Patuxent Wildlife Research Center to help save endangered whooping cranes. Site links to natural history information on whooping cranes, why they are endangered, cool facts on cranes, and a photo gallery.
This endangered species prefers native trees in large, continuous areas of riparian habitat. Armed with this information, resource managers may identify and preserve areas favorable to this population.
Report on use of strip-transect aerial surveys to obtain minimum manatee counts and distribution information in area of Ten Thousand Islands, Florida, with maps, diagrams, and information on method and results.
Summarizes studies that took place in this ecoregion. Some studies occurred in areas without post-fire management, and others in moderately or intensively managed areas. Some of the research also occurred immediately after a wildfire, and other work occur