Consistency in Egg Rejection Behaviour: Responses to Repeated Brood Parasitism in the Blackcap (Sylvia atricapilla)

• DOI: 10.1111/j.1439-0310.2007.01340.x
• Publication Date: 2007-03-27T11:14:19Z
• Authors: Marcel Honza; Milica Požgayová; Petr Procházka; Emil Tkadlec
• Keywords: 0106 biological sciences; 01 natural sciences

AbstractTo evaluate host responses towards repeated brood parasitism we experimentally parasitized and continuously videotaped blackcap nests in two consecutive trials. The ejection of a foreign egg was the most common response (94.5%) in both trials, but desertion (4.1%) and acceptance (1.4%) also occurred. The general method of ejection was puncturing. In 9.8% of identified ejections, already punctured eggs stuck to the abdominal feathers of the incubating bird and were carried out of the nest. Females were responsible for the majority of ejections in both trials and their response time was significantly shorter than that of males. Blackcaps exhibited consistency in the sex responsible for egg ejection over the two trials; but in five (20.8%) experiments individuals changed their behaviour. Repeatability for host responses within the nest was very high. In ejections accomplished by the same bird, the response was significantly quicker in the second trial, indicating the presence of certain learning abilities. Our results suggest that cuckoo hosts are quite consistent in their responses towards parasitic eggs when parasitized repeatedly within one breeding attempt.