Terrestrial Mammals

Southern Arizona’s semi-desert grasslands provides habitat for flora and fauna, regulates rainfall infiltration and overland flow, mitigates surface erosion and dust production, and sequesters carbon. Sustainable management is important to maintain these ecological services and is of concern for the managers, ranchers, and other people associated with the grassland.

National Wildlife Refuges provide habitat for important fish and wildlife species and services that benefit coastal communities, like storm-surge protection. USGS scientists are helping coastal refuges plan for and adapt to sea-level rise.

Badlands National Park (BADL) contains one of the largest protected expanses of mixed-grass prairie in the United States, much of which supports a herd of nearly wild bison. The park nevertheless is too small to accommodate bison’s natural nomadic behavior, which in the past resulted in their ephemeral but intense influence on Great Plains grasslands. This research is assessing the spatial...

Badlands National Park contains the largest contiguous bison range in the core of the species’ historic range on the northern Great Plains. The park nevertheless is too small to accommodate natural movements of free-ranging bison. As a result, continual grazing by resident bison has supplanted intense-but-ephemeral grazing by nomadic bison. The herd also is currently too small to prevent gradual...

Wolves on Ellesmere Island, just south of the North Pole, survive in extreme cold during 24 hours of darkness per day from November through January, and survive in much higher temperatures during 24 hours of light per day from April through September. Partnering with other agencies, we use GPS radio collars applied to wolves during summer to examine wolf-pack movements on Ellesmere Island...

The National Park Service and U.S. Fish and Wildlife Service reintroduced wolves into Yellowstone National Park in 1995 and 1996. This study helps assess that population’s recovery and determine factors that affect the population, including diseases, intraspecific strife, and interactions with prey. The restoration has been very successful, and the population has persisted for more than 20 years...

When the wolf was listed as endangered, the last remaining mainland wolf population in the lower 48 states was in the Superior National Forest (SNF) of northeastern Minnesota. Since then, using radiocollaring and aerial tracking, we have studied the wolf population trend, factors influencing it, and prey species, white-tailed deer, moose, and beavers, affected by wolves. During winter 2018-2019...

The presence of top predators is considered an indication of ecosystem health and can play a vital role in ecosystem functioning by promoting biodiversity, and can contribute to regulating prey species abundance, and herbivory. In the intermountain west, the largest mammalian predator and obligate carnivore is the mountain lion, Puma concolor. This elusive and wide-ranging predator occupies a...

Most national parks interact with adjacent lands because their boundaries fail to encompass all regional habitats, species pools, and migration routes. Activities planned for adjacent lands can have adverse effects on park resources and visitor experiences. For example, fragmentation of adjacent habitat into smaller and more isolated remnants may influence the suitability of park habitat for a...

Maintaining a current understanding of ecological conditions is fundamental to the National Park Service in meeting its mission to preserve park resources in an unimpaired state for future generations. Ecological monitoring establishes reference conditions, which over time help to define the normal limits of natural variation, determine standards for comparing future changes, and identify the need...

Citizen scientists can now help dig into San Diego's urban wildlife mysteries. Join WERC ecologists as they track wild badgers and explore the connectivity of Southern California's natural landscapes.

National parks and other protected areas are key components of the wildlife conservation landscape. The goal of wildlife managers in national parks is to preserve the ecological integrity and authenticity of natural systems for future generations. Wildlife populations of national parks, however, are in continuous flux as a result of changing land uses outside their boundaries, climate variability...