Effects of ectoparasites of young on parents' behaviour in a Mediterranean population of Blue Tits

In altricial birds, adults are expected to alleviate the impact of parasitism on their young by increasing parental care. We experimentally investigated the effects of blowfly parasitism on adult behaviour in the nest cavity in a population of Blue Tits in which nestlings are heavily parasitized by blowfly larvae. The behaviour of males and females was different, since only the females carried out nest sanitation activities related to the presence of parasites. The time females devoted to nest sanitation was higher in parasitized nests than in experimentally deparasitized ones, suggesting that chicks and adults might share the costs of blowfly parasitism.