Avian abundance, diversity and post-fledging dispersal in riparian and upland forests in Northern Lower Michigan

Abstract

Riparian corridores have been shown to be important habitat for a higher number of avian species compared to upland habitat in southern Lower Michigan, Upper Michigan, and in regions nationwide. The main objective of this study was to determine if riparian habitat has higher abundances and diversity of avifauna compared to upland forest habitat in northern Lower Michigan, with a focus on avian productivity and juvenile abundance. Avian populations were analyzed in accordance with the Monitoring Avian Productivity and Survivalship (MAPS) project at the University of Michigan Biological Station (UMBS) in Pellston, MI. Mist-nets were set up in both riparian and upland habitat. There were 22 species captured exclusively in riparian habitat, and only 3 species captured exclusively in upland habitat. There were 8 species found with significantly higher abundances in riparian habitats, as well as 6 species with higher juvenile abundances. Both juveniles of species that favor upland, interior habitat (Ovenbirds (Seiurus aurocapilla) and Hermit Thrushes (Catharus guttatus)) and forest edge habitat (Song Sparrow (Melospiza melodia)) dispersed toward riparian habitat during the post-fledging period. Conservation managers should take into account increased avian diversity and post-fledging habitat use in the conservation and protection of riparian corridors.