Colonial seabird's paralytic perfume slows lice down: an opportunity for parasite-mediated selection?

摘要: Selection for chemical signals in birds could be influenced by parasitism as has been previously suggested visual and acoustic displays. Crested auklets (Aethia cristatella), colonial seabirds from Alaska Siberia, offer an example of how this might occur. secrete lipids plumage, possibly indicator status attractiveness. Prominent among these secretions are aldehydes, which noticeable a pungent citrus-like odour. Octanal hexanal, the most abundant aldehydes plumage crested auklets, potent invertebrate repellents, reported defenses heteropteran insects. These occur at high concentrations within specialized secretory structures. Experiments presented here show that compounds can paralyse lice. Lice obtained were paralysed or killed seconds after exposure to volatiles nicks integument auklet. Chemical analysis demonstrated presence area used experiment. exposed control tissues same manner not affected. A synthetic blend auklet odourant constituents caused sequence impaired behaviours lice comparable effects neuroactive insecticides. The time until onset was dependent on dose, suggesting rate molecular diffusion into louse spiracles explanatory factor. Impairment evident even very low during winter. aqueous emulsions present both experimental treatments but controls experiments inhabit crowded social neighbourhoods with larger groups, closer interindividual spacing higher rates contact than sympatric least pusilla). This help explain why have abundances. spread through direct between hosts louse-infected mates transmit offspring. Large differences loads fledglings suggest parental transmission