Midwest Fish & Wildlife Conference 2018

AUTHORS: Sarah Fischer, University of Toledo; Henry Streby, University of Toledo; Kathy Granillo, U.S. Fish & Wildlife Service; Henry Stevens, Tufts University; Claire Nemes, Ball State University

ABSTRACT: Gray Vireos (Vireo vicinior) are small, short-distance migratory songbirds that breed primarily in piñon (Pinus spp.) –juniper (Juniperus spp.) systems in the Southwestern United States and Northwestern Mexico. Compared to most other bird species in North America, Gray Vireos are understudied throughout their range, prohibiting beneficial management strategies and conservation plans. Additionally, the majority of studies that focus on this species concentrate on their nesting stage (i.e., nesting success as a measure of productivity). However, studying the full annual cycle of birds is of extreme importance in order to gain a more complete understanding of their biology, and studying the post-fledging stage is essential to determine full-season productivity. From May-August, we monitored n=29 nests in 2016 and n=51 nests in 2017 on the Sevilleta National Wildlife Refuge, New Mexico. In 2016, we found 24% nest success and a 38% parasitism rate by Brown-headed Cowbirds (Molothrus ater). In 2017, we found 25% apparent nest success, and a 43% parasitism rate. We also documented an individual attempting a maximum of n=5 active nests during one breeding season. Additionally, in 2017, we tracked n=32 juveniles daily using radio telemetry to determine post-fledging movements, survival, and habitat associations; we found a 66% juvenile survival rate.