Amphibian Research and Monitoring Initiative (ARMI) in the Appalachian Region

Robin E. Jung, Karen C. Rice, C. Kenneth Dodd, Jr., W. Brian Hughes

Presented at the USGS Appalachian Region Integrated Science Workshop, Oct 22-26, 2001, Gatlinburg, TN.

Introduction

The eastern half of the United States supports the greatest amphibian diversity north of Mexico (Figure 1).  The Appalachian region supports approximately 93 species, 60 of which belong to the family Plethodontidae (lungless salamanders).  However, the Appalachians are subject to some serious threats to amphibian habitats in North America, including habitat loss, degradation and fragmentation, acid precipitation, and point- and non-point source pollutants.

In response to global concerns for amphibian health and survival, Congress devoted funds to the U.S. Geological Survey in 1999 to establish the Amphibian Research and Monitoring Initiative (ARMI). Two major objectives of the ARMI are to:

• Determine the status and trends of amphibian populations on Department of Interior lands
• Determine causes of declines, malformations and diseases.

Although the ARMI is national in scope, two of its regions (Northeast and Southeast) encompass the Appalachian Region (Figure 2).  ARMI biologists and hydrologists are working together to understand the biological and hydrological factors (Figure 3) that affect amphibians and their habitats. The multidisciplinary effort combines amphibian research on life history and population status with water quality and hydrological data.

Figure 1.  Amphibian species densities north of Mexico (Duellman and Sweet, 1999).

Southern leopard frog
(Rana sphenocephala)
Photo by Priya Nanjappa

Methods

ARMI Components:

• Collect historical information on amphibian populations
• Conduct inventories
• Establish index sites for long-term monitoring and research
• Collect habitat, environmental, and water quality data
• Develop models of species-habitat associations
• Establish study sites on DOI lands to allow for statistically valid inferences on the status of amphibians using percent area occupied methodology
• Develop sampling protocols and methods to estimate amphibian populations and determine population trends
• Assist in the determination of causes of die-offs, diseases and malformations
• Coordinate data collection with other DOI agencies
• Expand scope of monitoring by including partnerships with states, NGOs, and university researchers
• Make information on status of amphibians available to partners and general public

Some Amphibian Survey Techniques:

• Area-constrained surveys (e.g., quadrat, transect)
• Time-constrained surveys
• Visual encounter surveys
• Dip net sweeps (larvae, aquatic salamanders)
• Call surveys (calling frogs)
• Automated recording systems (frogloggers for calling frogs)
• PVC pipes (on trees or ground as tree frog refugia)
• Coverboards (terrestrial, shoreline)
• Drift fences, usually in conjunction with pitfall traps, funnel traps and/or coverboards
• Funnel/minnow traps (larvae, aquatic salamanders)
• Leaf litter refugia bags
• Egg mass surveys

Figure 3.  The Great Smoky Mountains and Shenandoah National Parks are lands of contrast, where nearly dry streams turn into raging torrents, indicating the need to study biology in conjunction with hydrology and water quality.

Status

In Great Smoky Mountains National Park:

• 27 long-term plots at 9 sites (4,456 salamanders in 1998-2000)
• Time- and area-constrained surveys (terrestrial and aquatic) at > 500 locations throughout Park
• Monthly surveys of Gregory's Cave
• Sampling "historic" sites
• Distribution of green salamander (D. aeneus) and other rare species
• Testing leaf litter bags to sample salamander larvae
• Monitoring suspected disease in Cades Cove
• Landscape ecology of salamanders
• Repeated count surveys are probably not useful for tracking population trends
• Development of innovative statistical approaches to sampling (SR indices); determined high species detection probabilities
• In 1998, several recently metamorphosed dead wood frogs
• (Rana sylvatica) were observed at Gum Swamp
• In 1999 and 2000, sick or dead tadpoles, metamorphs and subadult Ambystoma opacum, A. maculatum, Rana palustris and R. sylvatica found at Gourley Pond
• Analysis by USGS National Wildlife Health Center showed:
1. histologic changes in livers and pancreas consistent with viral infection; presumptive diagnosis – iridovirus
2. evidence of the fungus Ichthyophonus (a fish fungus) on one Ambystoma

In Shenandoah National Park:

• 24 long-term plots at 5 sites
• Conducting egg mass counts of wood frogs and spotted salamanders at three ponds
• Stratified random survey of terrestrial and streamside salamanders at 49 sites throughout Park
• Compiling voucher and observational records to produce amphibian and reptile distributional maps for Park
• Estimated populations of terrestrial and streamside salamander populations using capture-recapture and removal techniques
• Compared four survey methods for streamside salamanders
• Tracking effects of prescribed burn on red-backed salamanders (Plethodon cinereus)
• Testing use of artificial cover boards for terrestrial salamanders
• Northern dusky (Desmognathus fuscus) and spring salamander (Gyrinophilus porphyriticus) abundance negatively correlated with water temperature (r > -0.28, df = 47, P < 0.05)

Reference

Duellman, W.E. and S.S. Sweet. 1999. Distributional patterns of amphibians in the Nearctic Region of North America. Pp. 31-109 in: W.E. Duellman (ed.), Patterns of Distributions of Amphibians: A Global Perspective. Johns Hopkins University Press, Baltimore, MD.