Threatened and Endangered Species

WERC wildlife biologist Dr. Kristin Berry has more than forty years of experience studying Agassiz’s desert tortoise. As the lead on several USGS projects, Dr. Berry continues to lend her expertise to investigating the status, genetics, and behavior of Agassiz’s tortoise populations in the Mojave Desert.

Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...

The Challenge: Whooping cranes have been successfully introduced using costume rearing techniques in either a direct autumn release or in an ultralight led migration from Wisconsin to Florida. In Florida, we have also released parent-reared whooping cranes. Not much is known about the learning that takes place in this K-selected species over the almost one year that the young whooping crane colt...

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...

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...

The Shenandoah salamander is an endangered salamander that is at risk of extinction due to its small, high-elevation range, competition with the co-occurring red-backed salamander, and the predicted future climate in the Appalachian mountain range. We are working with multiple partners to understand the current status of the species, predict future extinction risk, and continually engage...

Population models developed by USGS are the primary decision-support tools used for status assessments, and rely on estimates of adult survival and reproduction rates from mark-recapture studies.

The Challenge: The Laysan Teal is an endangered, endemic, Hawaiian dabbling duck that has been pushed to the brink of extinction numerous times. The previous range includes the Main and Northwestern Hawaiian Islands, and its current range is less than 10 sq. km within the National Wildlife Refuges of Papahānaumokuākea Marine National Monument. This non-migratory waterfowl was eliminated from all...

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...

Nuclear microsatellite markers have been developed and implemented on ~2,000 West Indian manatees. These markers provide individual genetic fingerprints for mark-recapture studies, population structure information for the conservation of unique or isolated populations, and pedigree and relatedness information for addressing inbreeding and breeding structure patterns.

Grasslands are arguably one of the most anthropogenically stressed ecosystems of the western United States. The highly endangered black-footed ferret and prairie dogs epitomize grassland mammals of high conservation concern.

A multi-agency effort assesses the health of manatees and provides baseline information on their health, reproductive status, and nutritional condition.