Reptiles

We are working closely with multiple partners to provide updated information, model potential outcomes, and identify key uncertainties relevant to amphibian and reptile species proposed for listing in the northeast US. We also provide timely science to partners to assist in recovery of listed species, which may involve field research, data analysis, or decision support.

USGS is applying decision analysis to identify cost-effective methods for controlling invasive species like the Argentine black and white tegu.

Because the American alligator ( Alligator mississippiensis) is a keystone species of the Everglades ecosystem, managers need a way to quantitatively assess the effects of alternative restoration scenarios on alligators.

Many species of amphibians and reptiles are declining or facing population threats in the West related to habitat loss, habitat alteration, introduction of non-native species, and other factors. Our work focuses on the status and trends of resident herpetofauna and how to better manage their habitats. Much of the effort is undertaken with cooperators, particularly with other agencies in the...

This project improves our understanding of the ecology of reptiles in California and evaluates methods of managing landscapes and these imperiled species. In particular, Dr. Brian Halstead examines the distribution and demography of reptiles to understand factors that affect where they are found and how populations change. He further explores the relationships of reptiles with their abiotic and...

WERC's Dr. Amy Vandergast and colleagues merge genetic data with mapping and modeling tools to inform biodiversity conservation efforts. They define evolutionary significant units within species, reveal evolutionary mechanisms responsible for diversification, and identify regions with high genetic diversity for protection.

The desert tortoise is listed as “threatened” under the Endangered Species Act. USGS WERC scientists, along with project partners have been conducting long-term analyses on how changes in the southwestern deserts of the United States can affect desert tortoise populations. Dr. Todd Esque and his team are investigating how habitat disturbances and restoration projects influence tortoise populations...

Dr. Robert Fisher and his colleagues have teamed up with the U.S. Fish and Wildlife, The Nature Conservancy and multiple universities to conduct several types of studies that will address high priority issues related to reptiles in the Pacific Basin Islands. These studies will provide new information about species diversity, endemicity, biology and demography of reptile fauna and will lay the...

As resource managers balance the needs of humans and wildlife, WERC’s Dr. Berry provides the necessary science to inform decisions on shared lands. Visit the “Science” tab to delve into specific projects.

The deserts of the Southwest are under increasing pressure from growing human communities. The spread of cities, agricultural fields, grazing livestock, power plants, and other forms of human development in the past and present have affected the region’s natural resources, including its wildlife. WERC’s Dr. Kristin Berry is studying the response of threatened desert tortoises to changing habitats...

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.

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...