Tools and Technology

Years after the last inmate departed Alcatraz Island, waterbirds like Black-crowned Night Herons and Snowy Egrets still make the forbidding island their home. The National Park Service has requested the aid of WERC’s Dr. Pete Coates to inform efforts to expand visitor access to the Island, and simultaneously maintain healthy waterbird populations.

The Golden-winged Warbler (Vermivora chrysoptera) is a species of considerable conservation concern in North America, primarily due to widespread population declines attributable to habitat loss (Confer et al. 1992, Buehler et al. ) and displacement by the Blue-winged Warbler (V. pinus) in areas of sympatry (Gill 1980, 2004; Will 1986). Recent research highlighted an important mechanism in the...

Mammalian predation is a major factor influencing waterfowl productivity in the Prairie Pothole Region. Rates of predation of waterfowl nests differ by predator species, so understanding landscape or spatial patterns in predator density are desired by many natural resource managers. Spatial predictions for the occurrence and relative abundance of predators would allow natural resource managers to...

Bat Research Bats are nocturnal, flying mammals that eat insects or fruits, pollinate flowers, distribute seeds, and are important to many ecosystems. Across North America there are 45 species of bats, many of which are threatened or endangered. One species of federally endangered bat, the Indiana bat (Myotis sodalis), is a medium-sized, gray, black, or chestnut brown bat living primarily in...

Although it is not listed on the Federal Endangered Species list, there is considerable concern over northern leopard frog declines in western North America. It is listed as a “special concern” species by some state wildlife agencies (e.g., Arizona Game and Fish Department 1996) and declines have been reported in Arizona, Colorado, New Mexico, and other areas across the west. Leopard frogs have...

Biologists at USGS Patuxent, as well as cooperating agencies are constantly looking for new ways of answering questions about the status of animal populations and how animal populations change over time. To address these questions, data are collected on captures and or sightings of animals which can be used to estimate parameters which affect the population using legacy software. Over time, new...

Managing a species with intensive tools like reintroduction may focus on single sites or entire landscapes. For mobile species like the federally-threatened Chiricahua leopard frog (Lithobates chiricahuensis [CLF]), both suitable colonization sites and suitable dispersal corridors between sites are needed. Following the eradication of the invasive American bullfrog (Lithobates catesbeianus) from...

Turtles are among the most recognizable and iconic of animals. Any animal with a shell and a backbone is a turtle whether they are called turtles, tortoises, or terrapins. In fact, terrapin is an Algonquian Native American name for turtle. Worldwide there are 356 turtle species on all continents except for Antarctica. The United States has more species than any other country with about 62...

Desert bighorn sheep populations in the southwestern United States are subject to non-native disease outbreaks, habitat loss, and genetic isolation that can threaten their long-term sustainability. In some regions of the southwest, mountain lion predation on desert bighorn sheep has been found to be the primary source of mortality. Grand Canyon National Park is home to one of the largest desert...

As a result of growing human populations, many areas have become urbanized and highly developed, leaving natural native habitats fragmented across the landscape. In southern California many of the remaining patches on native habitat are bisected by major, multi-lane highway systems. Threats to the long-term sustainability of native wildlife populations include genetic isolation, where inbreeding...

Social and Economic Analysis Branch Social Scientists investigate the process of environmental decision making and how stakeholder engagement strategies, policies, institutions, and decision support tools influence management outcomes.

The Challenge: Florida manatees are threatened by watercraft-related mortality, the potential loss of warmwater habitat, red tide events, and other anthropogenic factors. The USFWS and the Florida Fish and Wildlife Conservation Commission have regulatory authorities under the Endangered Species Act (ESA), the Marine Mammal Protection Act (MMPA), and state statutes to recover manatees. To support...