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Dr. Bruce Kingsbury
Department of Biology
Indiana University – Purdue University Fort Wayne
Amphibians are of great conservation concern due to alarming population declines worldwide. These vulnerable species are threatened by habitat loss and degradation, especially in the midwestern United States. Efforts to restore wetland habitat can mitigate some aspects of habitat loss, but effective sampling techniques and suitable analytical approaches are needed to accurately measure the quality and functionality of the restored habitat. Occupancy modeling was applied to amphibians inhabiting a 716 acre restored wetland system in northeast Indiana in 2013 and 2014. Two types of survey methods, call surveys and tadpole surveys, were used to measure and compare amphibian presence and absence in forested, established wetlands and open, restored wetlands. Occupancy models based on habitat type revealed most species used both types of wetlands, with the exception of Ambystoma LTJ hybrid salamanders which bred exclusively in the forested, established wetlands. Factors affecting occupancy and habitat use varied among species, suggesting habitat preference is species-specific. Across both years, tadpole occupancy rates were the highest in the Northern Leopard Frog, Lithobates pipiens, a species of special concern in Indiana. Occupancy probability of calling American Bullfrogs, Lithobates catesbeiana, declined significantly in 2014, while rates of the Northern Cricket Frog, Acris crepitans, also a species of special concern, remained equal in both years. Across almost all species, occupancy rates were significantly higher for calling males than for tadpoles. Management decisions are often based on wetland characteristics where frogs call, but should also take into account habitat where reproduction is successful. These results on occupancy and metapopulation dynamics will be used to gauge population health and restoration success while providing management suggestions for the preserve and surrounding areas.
Biology | Life Sciences
Stulik, Emily, "Amphibian Occupancy, Habitat Use, and Reproductive Success in a System of Restored Wetlands" (2015). 2015 IPFW Student Research and Creative Endeavor Symposium. 67.