Landscape Factors that Influence European Starling (Sturnus vulgaris) Nest Box Occupancy at NASA Plum Brook Station (PBS), Erie County, Ohio, USA

During the last decade at NASA Plum Brook Station (PBS), Erie County, Ohio, United States, there has been a nearly 50% decrease in European Starling ( Sturnus vulgaris ) occupancy (nests with ≥1 egg) of nest boxes designed to be used by starlings. Increased availability of natural cavities, from invertebrate pests, might have altered nest box occupation rates. It was hypothesized that starling nest box occupation rates would be a function of an index of potentially suitable tree cavities for nesting starlings, the semi-colonial nature of breeding starlings, and access to foraging areas (e.g., mowed lawns near buildings). Specifically, it was predicted that starling occupancy of nest boxes would correlate positively with a low density of potentially suitable tree cavities (calculated from a constructed index based on characteristics preferred by nesting starlings), and proximity of other starling occupied nest boxes and anthropogenic structures or mowed lawns. The objective was to quantify landscape factors around nest boxes with known starling occupation rates. Potentially suitable tree cavities were readily available near nest boxes. However, starling nest box occupation was instead a function of proximity to buildings, a factor associated with additional nesting sites and preferred foraging areas (mowed lawns). Nesting starlings in this study were influenced by anthropogenic structures and associated resources.