Increasing number of point counts influences estimates of bird and anuran species richness at the wetland scale

• Published in: Wetlands ecology and management Vol. 30; no. 1; pp. 99 - 110
• Main Authors: Podoliak, Jon, Norment, Christopher J., Amatangelo, Kathryn L.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2022; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Birds; Conservation Biology/Ecology; Environmental Law/Policy/Ecojustice; Environmental restoration; Freshwater & Marine Ecology; Habitat loss; Hydrology/Water Resources; Lakes; Life Sciences; Marine & Freshwater Sciences; Marshes; Methods; Monitoring; Original Paper; Sampling; Species richness; Water Quality/Water Pollution; Wetland restoration; Wetlands; Wildlife; Wildlife habitats; Wildlife management; Birds; Anurans; Monitoring; Wetlands; Great Lakes
• ISSN: 0923-4861; 1572-9834
• DOI: 10.1007/s11273-021-09837-1

The Laurentian Great Lakes of North America have seen major development of wetlands and wetland-associated landscapes. Monitoring of wetland species is important to determine impacts on wetland wildlife due to habitat loss, and to evaluate the effectiveness of wetland restoration efforts. However, methods used for monitoring species often depend on the spatial and temporal scales of the project, and some large-scale monitoring projects call for only two or three site visits per year. We sampled Great Lakes coastal wetlands for up to six visits for birds and nine visits for anurans and evaluated how community metrics changed as increasing numbers of samples were collected. Our goals were to determine how much increased site visits better detect entire communities and true species richness, and to evaluate if the rank of observed species richness among wetlands is preserved regardless of sampling effort. We found a significant increase in species richness using our intensive methods versus only two site visits for birds in 2015 and 2016 and versus only three visits for anurans in 1 year. Additionally, we found a strong correlation between species richness using two visits for birds in both years and three visits for anurans in 1 year and our more intensive methods. We found no significant difference in the richness or abundance of cryptic marsh bird species between two site visits and our more intensive visits. However, sampling more intensively did increase our detections of cryptic marsh bird species. Our results are especially useful to managers tasked with evaluating the success of local wetland restorations.