Lakeshore Vegetation Effects on Avian and Anuran Populations

Abstract

Riparian zones are hotspots of wildlife diversity and also particularly attractive for housing development. Landscaping associated with homes contributes to a wide range of lakeshore vegetation structures. Based on calling surveys in Northern Wisconsin, we investigated effects of lakeshore vegetation structure on bird diversity and frog abundance at three spatial scales: parcel (30 m of shoreline), whole-shore (340 m of shoreline) and whole-lake scales. For parcel and whole-shore scales, we selected sites paired by lake: 10 sites with an intact understory vegetation layer and 10 sites with a cleared understory. Green frog (Rana clamitans) abundances were somewhat related to presence of forest understory at the parcel scale. More clearly, we found higher avian species richness at sites with intact understory vegetation than those without, and increasing richness with canopy coverage. Aerial insect abundances, which were also higher at sites with an intact understory, may help explain bird distributions. Our results suggest that riparian understory landscaping at the scale of individual parcels can alter local bird communities.