Amphibians Monitoring

Amphibian populations and communities are a high-priority monitoring focus for most GULN parks. We have initiated development of a network-wide Amphibian Communities monitoring protocol in collaboration with staff at the University of Georgia 's Savannah River Ecology Laboratory. The primary objective of this protocol is to provide network parks with quantitative assessment and monitoring of common amphibian species as biological indicators of changing ecosystem conditions. Likely questions focus on local relative abundance, large-site occupancy, and age and sex structure within populations. Both sampling methodologies and sampling designs remain to be selected, but we anticipate that this protocol will utilize established methods and designs derived from current practices used by the Partners for Amphibian and Reptile Conservation and USGS-Amphibian and Reptile Monitoring Initiative.

Bufo valliceps , the Gulf Coast Toad, is common to most GULN parks, and may serve as a cross-parks comparative indicator for amphibian monitoring

Hyla squirella , the squirrel tree frog, on JELA's Barataria Preserve. This common species may serve in conditional monitoring of amphibians on several GULN parks.

Typical sampling methodologies include intercepting and trapping mobile individuals (pitfall traps, drift fencing, visual surveys), providing acceptable artificial habitat (cover-board sampling), conducting net and trap sampling in aquatic habitats, and using audio census methods (“frog-loggers,” listening surveys). Each of these methodologies involves different assumptions and practices concerning both spatial and temporal sampling distribution and intensity.

We expect that amphibian sampling will be environmentally stratified based on landform, elevation gradients, slope and exposure aspects, and substrate composition. Sampling points, plots, and transects may be distributed systematically across an entire park (based on a park map grid), within defined strata, or in semi-randomized and simple random designs within sample spaces. In many cases, sample locations will be specifically keyed to local habitat details. Amphibian experts frequently use habitat-targeted sampling due to the strong habitat specificity of many species. Sampling may involve multiple sampling visits per site over each season, as many species exhibit diel behavior patterns and seasonal activity cycles. We should expect that within-year sampling revisit schedules may be specific to a park, based on which species are common at that location. We anticipate that all parks included in this effort will be sampled every year, in a network-wide, one-panel revisit design.

All amphibian sampling will be spatially explicit, and sampling sites will be located with GPS coordinates. Use of geospatial locators will support a posteriori correlation of amphibian data with vegetation structure and geomorphic landform data (habitat structure and dimensionality) collected during those monitoring efforts.

Link to Amphibians Intranet page (NPS only)