Nest material preferences among European starlings (Sturnus vulgaris) with a focus on feathers and anthropogenic materials

Abstract

Avian nests provide critical shelter for offspring and differ in structure according to the species. They typically consist of natural materials such as dried grass, feathers from other species, and anthropogenic materials woven into them. The European starling (<i>Sturnus vulgaris</i>) is an urban-thriving cavity-nesting species. Their nests consist of both natural and anthropogenic materials taken from the surrounding area. Anthropogenic materials have been shown to reduce fledging success in certain species. Passerine research has previously revealed birds prefer unpigmented (white) feathers over pigmented feathers to incorporate into their nest, although a mixture of both may be present. Studies have demonstrated that unpigmented feathers result in greater hatching success. Along with that, the amount of feathers within a nest is positively correlated with growth rates among nestlings. Nests within nestboxes occupied by starlings in 2021 at Saint Mary’s University in Halifax, Nova Scotia were examined after fledging to document the amount of anthropogenic materials and feathers among them. Of these, 16 nests were collected from early broods, and 22 from late broods. The amount of anthropogenic materials and feathers did not differ between early and late broods. Brood condition tended to be negatively correlated with the amount of anthropogenic materials and was significantly negatively correlated with total feather mass within a nest. However, there was no detected relationship between hatching success and the amount of unpigmented feathers within a nest. Along with there being no detected relationship between the amount of anthropogenic materials and fledging success among nestlings. Anthropogenic materials and feathers appeared to have adverse effects on nestling condition, so it is surprising that they are abundant in many of their nests.