Landscape‐Driven Isolation Among, but High Genetic Diversity Within, Peripheral Populations of a Threatened Frog

ABSTRACT Aim Many amphibians are experiencing declines, which are exacerbated for populations near range edges. To inform conservation strategies, we sampled sites of Blanchard's Cricket Frog ( Acris blanchardi ) at the northern periphery of their range to determine if modern declines are associated with genetic factors, delineate management units, and understand how landscape features influence connectivity. Location The southern Lower Peninsula of Michigan, USA. Methods We genotyped 777 individuals from 41 sites using 14 microsatellite markers to assess genetic diversity, characterize population structure, and delineate management units. We modeled isolation by distance and the effect of landscape features on functional connectivity using maximum likelihood population effects (MLPE) models. Results Despite strong isolation among populations, genetic diversity appears high within Michigan sites. Twenty genetically distinct populations were identified, with evidence of local connectivity within multi‐site populations. Landscape genetic analyses revealed that development and roadways between sites hinder gene flow, while forest cover, pasture, and streams facilitate it. A strong isolation by distance pattern exists up to ~20 km, beyond which dispersal is unlikely and genetic drift predominates. Main Conclusions The observed genetic diversity of peripheral Acris blanchardi populations in Michigan suggests that recent declines are driven more by demographic factors than by genetic erosion. Management should prioritize preserving connectivity between nearby sites by limiting development, particularly roadways, and maintaining pasture, forest, and stream integrity. Conservation of these genetically diverse peripheral populations is critical for promoting future range shifts and long‐term species persistence under climate change.