Reactions of passerine birds to aposematic and non-aposematic firebugs (Pyrrhocoris apterus; Heteroptera)
Abstract
Reactions of nine passerine bird species, namely Parus major, Parus caeruleus, Aegithalos caudatus, Erithacus rubecula, Turdus merula, Sylvia atricapilla, Fringilla coelebs, Carduelis chloris, and Emberiza citrinella to the firebug Pyrrhocoris apterus wildtype (brachypterous adults) and its artificially obtained (painted) brown non-aposematic variant were compared. Most insectivorous birds (great tits, blue tits, robins and blackcaps) distinguished between aposematic and nonaposematic bugs, attacking the former less often.
Partly granivorous buntings and finches did not istinguish between them, and attacked both variants equally. As all the birds were caught in the wild, the results can be interpreted in terms of the presence of a higher proportion of experienced individuals among insectivorous than among omnivorous species.