title: The sight of an adult brood parasite near the nest is an insufficient cue for a honeyguide host to reject foreign eggs.
abstract: Hosts of brood-parasitic birds typically evolve anti-parasitism defences, including mobbing of parasitic intruders at the nest and the ability to recognize and reject foreign eggs from their clutches. The Greater HoneyguideIndicator indicatoris a virulent brood parasite that punctures host eggs and kills host young, and accordingly, a common host, the Little Bee-eaterMerops pusillusfrequently rejects entire clutches that have been parasitized. We predicted that given the high costs of accidentally rejecting an entire clutch, and that the experimental addition of a foreign egg is insufficient to induce this defence, Bee-eaters require the sight of an adult parasite near the nest as an additional cue for parasitism before they reject a clutch. We found that many Little Bee-eater parents mobbed Greater Honeyguide dummies while ignoring barbet control dummies, showing that they recognized them as a threat. Surprisingly, however, neither a dummy Honeyguide nor the presence of a foreign egg, either separately or in combination, was sufficient to stimulate egg rejection.
authors: Department of Zoology, University of Cambridge Downing Street, Cambridge, CB2 3EJ, UK.
authors: Wenfei
authors: W
authors: Tong
authors: Department of Zoology, University of Cambridge Downing Street, Cambridge, CB2 3EJ, UK.
authors: Nicholas P C
authors: NP
authors: Horrocks
authors: Department of Zoology, University of Cambridge Downing Street, Cambridge, CB2 3EJ, UK ; Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town Rondebosch, 7701, South Africa.
authors: Claire N
authors: CN
authors: Spottiswoode
keywords: brood parasitism; egg rejection; frontline defences; mobbing