Herpetology

Program Goals

1. To conduct basic and applied research on the biology, and especially the life history and conservation, of amphibians and reptiles.

2. To focus on federal lands, primarily in the Southeastern United States and Caribbean.

3. To disseminate information on the biology and conservation of amphibians and reptiles, and on the ecosystems on which they depend.

4. To provide professional and unbiased information based on sound scientific analysis.

Current Research

Southeastern Amphibian Research and Monitoring Initiative (SE ARMI)

The objectives of this initiative are (1) to determine the status and trends of amphibian populations on Interior Department lands in the southeastern United States, Puerto Rico, and the U.S. Virgin Islands, and (2) to provide information useful in determining causes of declines should they be discovered. Larger tracts of DOI land, such as the Great Smoky Mountains National Park, Okefenokee National Wildlife Refuge, and the large parks of south Florida, should be of sufficient size to allow the determination of species trends, particularly of localized endemics.

1. Study sites will be established in a manner that allows for statistically valid estimates of the status of amphibians within the boundaries of individual DOI lands and changes in the abundance and distribution of selected amphibian species in larger landscapes centered on large DOI lands.

2. For species and habitats where existing methods are inadequate to collect data on trends, research will be conducted to develop sampling protocols and appropriate methods to analyze data, detect trends, and make predictions concerning status.

3. Ancillary biological and physical data will be collected so that causes of changes in abundance and distribution can be determined.

4. Should emergency situations be detected, such as the presence of disease or malformations, research will assist in the determination of cause and methods of containment.

5. Data collection will be coordinated within USGS, among DOI and other federal agencies. Efforts to recruit partners among State agencies, university researchers, and non-governmental organizations will seek to expand the scope, scale, and interpretive value of work conducted by USGS.

6. Information will be made available to cooperating agencies, the scientific community, and the public.

Long-Term Studies of Florida Box Turtles

Since 1991, USGS/FISC researchers have marked >1600 Florida box turtles, with > 4000 individual captures, on Egmont Key National Wildlife Refuge. The purpose of this long-term project is to gather information on the life history of this species and to determine the effects of island restoration on the large population of resident turtles. To date, substantial data have been collected on the demography, population structure, activity patterns, habitat use, and behavior of these turtles. These data have been used to make critical management recommendations regarding island restoration. In addition, the results have implications for determining the response of long-lived animals to take and other forms of  perturbations in their environment. Below are excerpt images from a powerpoint presentation on Box Turtles from Egmont Key National Wildlife Refuge, courtesy of C. Kenneth Dodd, Jr.

                    

frame 1 | frame 2 |  frame 3 |  frame 4 |  frame 5 |  frame 6

Previous Research

The Great Smoky Mountains National Park
Inventory and Monitoring Project

The problem of declining amphibian populations has been recognized world wide, with credible reports of diminishment or disappearance of amphibians from many regions and habitat types.  No single cause for declines has been demonstrated, although acid precipitation, environmental contaminants, introduction of exotic predators, disease agents, parasites, and effects of ultraviolet radiation have been suggested to be involved in some declines.  Indeed, no one cause may be implicated, and several factors may interact in such a manner as to threaten populations. A major factor in the loss of amphibian populations has been and continues to be the loss of habitat. The severity and apparent complexity of the problem led the National Park Service in 1997 to list amphibian declines as among its highest priority research and information needs. In the United States, amphibian declines were first documented in the western States, where many populations tend to be small and isolated, and on the island of Puerto Rico. However, the scope of declines observed elsewhere suggests that vigilance is needed in all regions of the nation.

In terms of its significance to amphibians, the Great Smoky Mountains National Park is more important than almost anywhere else in North America.  Thirty one species of salamanders have been recorded in the Park, and that number could conceivably increase as biochemical techniques are used to unravel the complex relationships among populations.  Of particular note are the salamanders of the Family Plethodontidae, a largely North American group that has a center of evolution and distribution in the Southern Appalachians. The red-cheeked morph of Plethodon jordani is known only from the Park, and the salamander fauna is believed to represent several evolutionary series progressing from more aquatic species to those which are almost totally terrestrial. Thirteen species of frogs and toads have been reported historically to inhabit the park. The biological importance of the Park has been recognized in its designation as an International Biosphere Reserve. Although no other region and no other National Park shares the wealth of amphibians found in the Great Smokies, the entire southern and midsection of the Appalachian chain is characterized by a high diversity of amphibians, and inventories and monitoring protocols developed in the Smokies may be applicable to other National Park Service properties in the Appalachians, including the Blue Ridge Parkway, Shenandoah National Park, Cumberland Gap, and Big South Fork National Recreation Area.

Several known stressors potentially affect amphibians in the 2071.2 km² (=521,000 acre) Park.  Air pollution, particularly long distance pollution from cities in the nation's mid-region, is a nationally recognized problem. Reduced visibility, damage to plants, and fish kills are documented to be associated with sulfurous and nitrogenous compounds and ozone in air. Low pH is known to have affected salamander survivorship in at least one aquatic Park species. Exotic pathogens and parasites have affected forest communities, with unknown effects on ecosystems. Finally, the pressure of nine million visits per year--more than any National Park--seems relatively benign, but could potentially have subtle effects on sensitive amphibian populations. The existence of these and other unknown stressors suggest that an inventory and a monitoring program are needed to ensure the protection of amphibian populations. The project began in the fall of 1997 and is scheduled to continue through the spring of 2001. At that time, the project's goals and accomplishments will be evaluated, and it is possible that scientific research will continue.

Purpose of the Research:

• Provide a geographically-referenced inventory of the amphibian resources of the Great Smoky Mountains National Park.
   
• Provide indices of abundance of Park amphibian species, referenced to locations and habitat types.
   
• Develop and transfer to the Great Smoky Mountains National Park and National Park Service a series of protocols suitable for long-term monitoring of amphibian populations in the Smokies and other Appalachian Parks.
   
• As possible, evaluate current distributions and abundance of amphibian species in the Park with literature reports of past investigations.

Other Amphibian Conservation Studies

We have conducted several studies relating to the conservation and management of threatened amphibians. Included are studies of the habitat characteristics and effects of forestry on the Red Hills Salamander (in Alabama) and the status and distribution of striped newts (in Georgia). These studies have quantitatively examined habitat variables to provide information on future management options. Detailed studies on the life-histories of several species have been completed. BRD personnel monitor the status of southeastern amphibians through contacts with other professional biologists.

Effectiveness of Highway Barriers to Prevent Vertebrate Mortality

USGS/FISC scientists are conducting an extensive evaluation of the effectiveness of highway barriers to reduce mortality and under-road culverts to facilitate intra-population movement across Paynes Prairie State Preserve in Alachua County, Florida. The barriers and culverts were installed by the Florida Department of Transportation in 1999-2000. USGS/FISC researchers are evaluating pre- and post-construction mortality and movement patterns. The results may lead to the development of a model system to significantly reduce the effects of highway mortality on wildlife. see: Paynes Prairie Ecopassage Project page.

Herpetofauna of the Endangered Longleaf Pine Community

This research began by evaluating the importance of a small temporary pond to a herpetofaunal community in upland sandhill habitats. More than16,000 amphibians and reptiles were captured. Our research yielded valuable information on life histories, population structure, orientation, the effects of drought, buffer zones, landscape dynamics, and management. Other sandhill projects involved inventories of the species using upland habitats, radio tracking snakes and turtles, and sampling techniques.

Exuma Islands Herpetofaunal Diversity and Biogeography

From 1991-1993, we conducted studies on the life history, biogeography and conservation of the herpetofauna of the Exuma Cays Land and Sea Park, Bahamas. Research was designed to assess herpetofaunal distribution and life history in order to assist the Bahamas in managing the national park.

Offshore Habitat Use By Marine Turtles

We attached satellite transmitters to four female loggerhead turtles (Caretta caretta) between 1988 and 1992, and followed their movements for 27 to 132 days. Each female took a different emigration path, although three of the turtles appeared to rest and passively drift with the Florida current for varying amounts of time. One turtle eventually moved south hugging the southeastern coast of the United States, a second turtle eventually swam through the Bahamas, and the third turtle remained in offshore habitats south of Cape Hatteras. The fourth turtle swam directly to the Bahama Islands. Two turtles eventually moved to the southern Great Bahama Bank where they were captured by Cuban fishermen. Dive and surfacing activity reflected water depth and swimming behavior. In shallow waters, loggerheads dove less often but remained underwater for longer periods of time than they did over deep waters. Passive turtles over deep water had longer surface times. Tropical storms and hurricanes might have affected the activity of two turtles, causing them to alter their swimming behavior and to seek shelter. Adverse weather also might have led to transmitter failure or detachment. Because loggerheads readily cross national boundaries, international cooperation is necessary to protect migratory pathways and foraging grounds, especially on the Great Bahama Bank.