Do birds behave in order to avoid disclosing their nest site?

Abstract

Capsule Three similarly sized passerine species with various breeding strategies behaved differently in the presence of models of mammalian and avian predators. Aims We tested whether solitary breeders behave in the presence of a predator in order to avoid disclosing their nest site in: hole-nesting Pied Flycatcher Ficedula hypoleuca, shrub-nesting Blackcap Sylvia atricapilla and ground-nesting Meadow Pipit Anthus pratensis. Methods The behaviour of parents in response to two types of predator model (visually oriented Corvid birds and olfactory oriented Mustelid mammals) placed sequentially at 40, 5 and 1 m distance from the nest was recorded from a shelter. Results The hypothesis was supported in open-nesting species (Meadow Pipit and Blackcap), as parents did not approach the nest in the presence of a predator. In the hole-nesting Pied Flycatcher the parents disclosed the nest site in most cases (by entering the nest). The intensity of alarm calling increased with decreasing distance of a predator from the nest in all species except Meadow Pipit in the presence of Raven Corvus corax models. The intensity of attacking changed only in Meadow Pipit with decreasing distance of Stoat Mustela erminea from the nest. Conclusion The results showed that anti-predator behaviour was species-specific, depending on type of predator, habitat and nest inaccessibility.