Urban Greenspace is for the Bluebirds: Nest-Box Selection across a Noise Gradient on an Urbanizing University Campus

Abstract

We assessed features characterizing the most attractive nest sites for Sialia sialis (Eastern Bluebird) in an urban setting, hypothesizing that noise and availability of open grass would significantly influence nest-box occupancy. In 2019, we monitored 72 nest boxes on the University of Florida campus and compared features of occupied and unoccupied boxes. Predictor variables included ambient noise, box orientation, percent grass (within 150 m), human activity, visibility from box, and distances to nearest high perch, road, occupied building, and grassy area (larger than 1 ha). The occupancy was significantly higher for boxes located where percent grass within 150 m was greatest and also where noise was lower. We conclude that conservation of viable populations of Eastern Bluebirds is compatible with integrated urban-greenspace planning. Further work is needed, however, to mitigate negative effects of noise on reproductive output.