National Park Service

Southeast Coast Network (SECN)

Parks in this Network

SECN Network Map
Click to see Larger
Network Map
Find your park logo

Amphibian Monitoring

Cope's grey treefrog at Chattahoochee River NRA
Cope's grey treefrog at Chattahoochee River NRA

Amphibian Monitoring Reports & Briefs

Amphibian Sampling Protocols & Procedures

For more information contact: Michael W. Byrne

Monitoring Objectives

  • Determine trends in amphibian species distribution, diversity, and detection/non-detection within SECN parks.
  • Determine trends in soil moisture, down woody debris (DWD) and duff depth within SECN parks (ties to Fire and Fuel Dynamics vital sign).
  • Determine trends in frequency of occurrence of Batrachochytrium dendrobatidis in amphibians in SECN Parks.

Background

Amphibian monitoring is a high priority because of their importance as indicators on a world-wide scale as well as the high level of diversity in the Southeast. Population declines have been noted by various research projects throughout the world due to disease, introduced predators, loss of habitat, acidification, or ultraviolet-B radiation damage to eggs (Flather et al. 1999, Reaser 2000). Amphibians are commonly recognized as useful species to evaluate environmental conditions. Most amphibians are dependent on both wetlands and upland habitats and are sensitive to perturbations and degradation of either habitats. Because of these characteristics, amphibians may be good indicators of local and regional ecosystem change and perturbation.

A chytrid fungus, B. dendrobatidis, has been attributed to localized population declines and extinctions worldwide (Berger et al. 1998, Daszak et al. 1999, Skerratt et al 2007). A fundamental understanding of B. dendrobatidis distribution, species-specific susceptibility, and species-specific effects remains limited. Preliminary work by the SECN has identified B. dendrobatidis in a species not previously known to be susceptible to the fungus (Byrne et al., 2008).

Monitoring Approach

Automated Recording Devices

Auditory surveys are appropriate for monitoring breeding populations of many frog and toad species that advertise their breeding activities with distinctive calls. The automated recording device (ARD) consists of a timer, digital recording device, and a microphone housed in a waterproof case. The device does not record environmental variables. The ARD is positioned at the center point of the macroplot. The ARD is programmed to record three minute intervals every 15 minutes for twelve hours (48 intervals / night) for three consecutive nights to facilitate generation of the percent area occupied (PAO) metric for all detected species. Data are downloaded the following day, batteries are checked, the memory is cleared, and the device is redeployed. Species accumulation curves will be generated during pilot implementation to determine the minimum amount of recording time necessary in order to maximize species diversity. The ARD will be deployed prior to implementing the visual encounter survey technique to minimize any possible confounding effects that technique might have on vocal-anuran presence.

Visual Encounter Surveys

All habitats and potential cover objects (e.g., leaf litter, under logs/rocks, other potential cover items) are searched and all species detected are identified and recorded. Animals are captured, if necessary, to facilitate accurate identification. If streams or wetlands are encountered within the macroplot, dip-nets and hand-capture is used, as necessary, to detect aquatic amphibians. All cover objects are returned to their original position to reduce habitat impacts. This method is time-constrained; however the duration of the survey within each macroplot will be determined through pilot implementation (ca 30 min.). Each 0.5-ha macroplot is systematically sampled with ten transects spaced 15m apart; five oriented north / south and five oriented east / west.

B. dendrobatidis

Sampling for the presence of B. dendrobatidis entails collecting skin swabs from captured individuals and conducting a polymerase chain reaction amplification of each sample using an established assay to determine the presence of the fungus. The level to which we will implement this component has yet to be determined.

⇑ To Top of Page

References

  • Berger, L, R. Speare, P. Daszak, D.E. Green, A.A. Cunnigham, C.L. Goggin, R. Slocombe, M.R. Ragani, A.D. Hyatt, K.R. McDonald, H.B. Hines, K.R. Lips, G. Marantelli, and H. Parkes. 1998. Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America. Proceedings of the National Academy of Science, USA 95:9031-9036.
  • Byrne, M.W., E.P. Davie, and J.W. Gibbons. 2008. Batrachochytrium dendrobatidis occurrence in Eurycea cirregera. Notes of the Southeastern Naturalist 7(3):551-555.
  • Daszak, P., L. Berger, A.A. Cunningham, A.D. Hyatt, D.E. Green, and R. Speare. 1999. Emerging infectious diseases and amphibian population declines. Emerging Infectious Diseases 5:735-748.
  • Flather, C.H., S. Brady, and M. Knowles. 1999. Wildlife Resource Trends in the United States. USDA Forest Service.
  • Reaser, J.K. Amphibian Declines: An Issue Overview. 2000. Washington, D.C.

 

Last Updated: December 30, 2016 Contact Webmaster