One person recording data as another installs a recording device at the base of a tree
Installing a frog song recorder, or "frog logger," at the brownstone quarry on Basswood Island, Apostle Islands National Lakeshore.


The lives of amphibians (frogs, toads, and salamanders) depend on both land and water, which helps in making various life stages accessible for study. Amphibians are also sensitive to changes in the environment, and that sensitivity is why there are rapid and widespread declines occurring among amphibian populations worldwide.

For these reasons, amphibians are a true "vital sign" for monitoring the health of park land and waters. Our monitoring efforts, combined with those of other federal and state agencies in the Great Lakes region, provide a broad context for comparing and evaluating amphibian population data.

Long-term Monitoring

Our goal is to provide data on trends in the size and distribution of amphibian populations over time. Specifically, we intend to:

  1. Monitor site occupancy through time, while accounting for variable detectability.
  2. Correlate trends in species distributions to environmental variables such as water chemistry, water depth, wetland size and composition, and type of surrounding habitat.
  3. Document the presence of amphibian species at selected wetlands in each park during the breeding season, and the relative abundances for several target species.
  4. Incidental to this monitoring, we will also track environmental conditions including changes in weather, water level and chemistry, land cover, and land use.

Our partner:

Great Lakes Ecological Services, LLC

Learn More

Briefs provide a one- or two-page overview of the latest findings and what they mean. Monitoring reports are in-depth technical reports that include data analyses and possibly management recommendations.


Source: Data Store Saved Search 385. To search for additional information, visit the Data Store.

Monitoring Reports

Source: Data Store Saved Search 406. To search for additional information, visit the Data Store.

Monitoring Protocol

Protocol documents detail precisely how monitoring is carried out.

Casper, G. S., E. Beever, U. Gafvert, and S. M. Nadeau. 2018. Amphibian monitoring protocol (version 2.0): Great Lakes Inventory and Monitoring Network. Natural Resource Report NPS/GLKN/NRR—2018/1761. National Park Service, Fort Collins, Colorado.

Last updated: October 11, 2018