Acoustic amphibian monitoring, 2019 data summary: Grand Portage National Monument
Casper GS, Nadeau SM, Parr TB. 2022. Acoustic amphibian monitoring, 2019 data summary: Grand Portage National Monument. Natural Resource Data Series. NPS/GLKN/NRDS—2022/1381. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/2295459
Amphibians are a Vital Sign indicator for monitoring long-term ecosystem health in seven national park units that comprise the Great Lakes Network. We present here the results for 2019 amphibian monitoring at Grand Portage National Monument (GRPO). Appendices contain tabular summaries for six years of cumulative results. The National Park Service Great Lakes Inventory and Monitoring Network established six permanent acoustic amphibian monitoring sites at GRPO in 2015. Acoustic samples are collected by placing automated recorders with omnidirectional stereo microphones at each of the sampling sites. Temperature loggers co-located with the recorders also collect air temperature during the sampling period. The monitoring program detected five of the eight species of frog and toad known to occur near Grand Portage National Monument in 2019, with Green Frog and Spring Peeper occurring at every site sampled, Eastern American Toad and Gray Treefrog at five sites each, and Wood Frog at two sites. Mink Frog was not found in 2019, although they were present in 2016 at GRPO01. Mink Frog is often difficult to detect due to quiet calls. Northern Leopard Frog and Boreal Chorus Frog have not yet been detected at the sites monitored by the GLKN program but are known to occur regionally. We expanded analyses and reporting in 2018 to address calling phenology and to provide metrics on abundance across years. Occupancy analyses track whether or not a site was occupied by a species. Abundance is tracked by assessing how the maximum call intensity changes on sites across years, and by how many automated detections are reported from sites across years. Using two independent survey methods, manual and automated, with large sample sizes continues to return reliable results. We recommend programming the units for a delayed start, then deploying them in autumn of the previous year for difficult-to-reach sites to better sample early calling species.
- Type
- Published Report
- Authors
- Casper, Gary; Nadeau, Stefanie; Parr, Thomas
- Date of Issue
- 2022-12
- Publisher
- National Park Service
- DOI
- 10.36967/2295459
- Units
- GLKN , GRPO , NRSS
- Keywords
- acoustic monitoring, Amphibian monitor, Grand Portage, Minnesota