Avian use of riparian habitats and the Conservation Reserve Program: Migratory stopover in agro-ecosystems
Erin B. Cashion, MS
Advisor: Paul Rodewald
Stopover habitat may be a limiting resource for migrant landbirds in agriculturally dominated regions of the Midwestern U.S., but few studies have examined the use of remnant natural and restored habitats in these landscapes. I conducted bird surveys and mist-netting from late August through late October in 2009 and 2010 at 19 sites in northwestern Ohio to identify small-scale (microhabitat structure and resource abundance) and large-scale (forest cover within 500m) habitat characteristics associated with bird abundances across a gradient of riparian habitat types. Restoration habitats had lower woody plant diversity and had lower bird abundances than non-restored habitats. Fruit-bearing shrubs, woody stem density, and woody species diversity were positively associated with capture and detection rates for transient species, both early successional and forest breeding species and obligate frugivores. Detection rates for Neotropical migrants and forest-breeding species were positively associated with increasing forest cover in the landscape while White-throated Sparrow (Zonotrichia albicollis) were negatively associated. Overall my results suggest that both local habitat characteristics and large-scale habitat features are important predictors of migrant abundances for some species and guilds. These results support previous findings that vegetatively complex habitats tend to contain higher densities of fall migrants and suggest that riparian forest restorations should incorporate fruit-bearing shrubs and a greater diversity of woody plant species to provide benefits to stopover migrant landbirds.