Interspecific parental care by a European Starling (Sturnus vulgaris) at the nest of a Hairy Woodpecker (Dryobates villosus)

Abstract

The European Starling (Sturnus vulgaris) is a cavity-nesting species that aggressively competes with other cavity nesters, such as woodpeckers, and usurps their nest cavities. Interspecific parental care among birds is uncommon and scarcely reported for European Starlings and woodpeckers. Here, we report an observation of a clutch of 3 Hairy Woodpecker (Dryobates villosus) nestlings being fed by both an adult female Hairy Woodpecker and at least 1 adult European Starling in southern Ontario, Canada. There are differences in parental behavior observed between the starling and female Hairy Woodpecker, namely only the starling entered the cavity (7.0 times/h) and removed fecal sacs (4.2 times/h) while the female Hairy Woodpecker never showed these behaviors during our observation period, but she fed nestlings 7.4 times/h compared to 4.9 times/h by the starling. Although proximate causes of this behavior are unclear, nest site competition, overlap of the timing of breeding and preferred habitat, or the loss of the male woodpecker may have triggered this behavior.