Monitoring Amphibians in
Great Smoky Mountains
By C. Kenneth Dodd, Jr.
__ Abstract __
Amphibian species have inexplicably declined or disappeared in many regions of the world, and in some instances, serious malformations have been observed. In the United States, amphibian declines frequently have occurred even in protected areas. Causes for the declines and malformations probably are varied and may not even be related. The seemingly sudden declines in widely separated areas, however, suggests a need to monitor amphibian populations as well as identify the causes when declines or malformations are discovered.
In 2000, the President of the United States and Congress directed Department of the Interior (DOI) agencies to develop a plan to monitor the trends in amphibian populations on DOI lands and to conduct research into possible causes of declines. The DOI has stewardship responsibilities over vast land holdings in the United States, much of it occupied by, or potential habitat for, amphibians. The U.S. Geological Survey (USGS) was given lead responsibility for planning and organizing this program, named the Amphibian Research and Monitoring Initiative (ARMI). Authorization carried the mandate to set up a national amphibian monitoring program on Federal lands, to develop the sampling techniques and biometrical analyses necessary to determine status and trends, and to identify possible causes of amphibian declines and malformations.
The biological importance of Great Smoky Mountains National Park has been recognized by its designation as an International Biosphere Reserve. As such, it is clearly the leading region of significance for amphibian research. Although no other region shares the wealth of amphibians as found in the Great Smokies (31 species of salamanders, and 13 of frogs), the entire southern and mid-section of the Appalachian Mountain chain is characterized by a high diversity of amphibians, and inventories and monitoring protocols developed in the Smokies likely will be applicable to other Appalachian National Park Service properties.
From 1998 to 2001, USGS biologists carried out a pilot inventory and monitoring research project in Great Smoky Mountains National Park. A variety of inventory, sampling, and monitoring techniques were employed and tested. These included wide-scale visual encounter surveys of amphibians at terrestrial and aquatic sites, intensive monitoring of selected plots, randomly placed small-grid plot sampling, litterbag sampling in streams, monitoring nesting females of selected species, call surveys, and monitoring specialized habitats, such as caves. Coupled with information derived from amphibian surveys on Federal lands using various other techniques (automated frog call data loggers, PVC pipes, drift fences, terrestrial and aquatic traps), an amphibian monitoring program was designed to best meet the needs of biologists and natural resource managers after taking into consideration the logistics, terrain, and life histories of the species found within Great Smoky Mountains National Park.
This report provides an overview of the Parks amphibians, the factors affecting their distribution, a review of important areas of biodiversity, and a summary of amphibian life history in the Southern Appalachians. In addition, survey techniques are described as well as examples of how the techniques are set up, a critique of what the results tell the observer, and a discussion of the limitations of the techniques and the data. The report reviews considerations for site selection, outlines steps for biosecurity and for processing diseased or dying animals, and provides resource managers with a decision tree on how to monitor the Parks amphibians based on different levels of available resources. It concludes with an extensive list of references for inventorying and monitoring amphibians. USGS and Great Smoky Mountains National Park biologists need to establish cooperative efforts and training to ensure that congressionally mandated amphibian surveys are performed in a statistically rigorous and biologically meaningful manner, and that amphibian populations on Federal lands are monitored to ensure their long-term survival. The research detailed in this report will aid these cooperative efforts.
The Florida Caribbean Science Center (now Florida Integrated Science Center) received funding in 1997 from the U.S. Geological Survey (USGS) Inventory and Monitoring (I&M) Program to conduct a pilot project for amphibians in the southeastern United States. After considering several locations, Great Smoky Mountains National Park (fig. 1) was selected for the survey because of its amphibian diversity and the large number of potential threats to its varied ecosystems (Brown, 2000). During the course of the next 4 years, a field research team of enthusiastic young biologists was assembled to collect information on the species richness and distribution of the Park’s amphibians. Researchers used a variety of sampling techniques, including 10 x 10-meter survey plots, permanent 30 x 40-meter plots, coverboards, litter-bag surveys, and a great number of time-constrained litter and stream searches. The team looked for previously reported rare species, sampled historic locations, investigated unique habitats (such as caves), and examined museum records and published literature. Survey activities and techniques were designed to optimize the use of available personnel within budget and logistic constraints. Survey teams sampled more than 500 sites (fig. 2) and recorded data on more than 10,000 amphibians. All parts of the Park were visited in all seasons and in all weather conditions.
The objectives of the Great Smoky Mountains National Park I&M program were to: (1) provide a geographically referenced inventory of the amphibian resources of the Great Smoky Mountains National Park; (2) provide indices of abundance of Park selected amphibian species, referenced to locations and habitat types; (3) 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; (4) evaluate current distributions and abundance of amphibian species as possible in the Park with literature reports of past investigations. This manual fulfills the third objective of the I&M program. Additional information on amphibian natural history, distribution, landscape ecology, trends analysis, and protocol development are published in Dodd and others, (2001), Waldron and others, (2003); Dodd, (2004), or is under development.
Figure 1. Great Smoky Mountains National Park, North Carolina and Tennessee. - click to enlarge
Figure 2. Location of U.S. Geological Survey sampling sites in Great Smoky Mountains National Park, 1998 to 2001. - click to enlarge
This manual is the result of collaborative survey efforts during 4 years of hard field work between 1998 and 2001 in the Great Smoky Mountains. The author would like to thank the following individuals for their support, assistance, dedication, and companionship: For their field collecting skill, expertise, and general good humor during all kinds of weather conditions, the USGS field crew from 1998 to 2001 (in alphabetical order): Jamie Barichivich, Jeff Corser, Elizabeth Domingue, Marian Griffey, Kelly Irwin, Christy Morgan, Rick ‘Bubba’ Owen, Kevin G. Smith, and Jayme Waldron. For figure 7: Todd Campbell. For advice: James Petranka and Chuck Smith.
For their support and assistance: the National Park Service personnel at Great Smoky Mountains National Park, particularly Keith Langdon, Dana Soehn, and Jack Piepenbring.
For providing funding: Norita Chaney (USGS Inventory and Monitoring Program, Reston, Virginia), Russell Hall (Florida Integrated Science Center), and the USGS Amphibian Research and Monitoring Initiative (ARMI).
For providing research permits: National Park Service (Great Smoky Mountains National Park), North Carolina Wildlife Resources Commission, Tennessee Wildlife Resources Agency.
For providing the beautiful illustrations of larval amphibians: Jacqualine Grant.
For reading the manuscript and making valuable comments: Jamie Barichivich, Marian Griffey, Russell Hall, Steve Johnson, Keith Langdon, and Jennifer Staiger.
How to Use This Guide