DOES MALE BADGE SIZE SIGNAL STATUS IN SMALL ISLAND POPULATIONS OF HOUSE SPARROWS, PASSER-DOMESTICUS

The relationship between dominance and throat badge size, body size, a nd body condition was examined in three small island populations of ho use sparrows, Passer domesticus, on the coast of northern Norway. Indi vidual dominance rank in males was determined by observation of agonis tic interactions in an artificial observation cage (one replicate in D ec. and one in Mar. in two populations and one replicate in Mar. in th e third population). Previous studies had indicated that badge size si gnals status in house sparrows. In this study, because of the small po pulation sizes and stability in their membership, we expected that pri or information about fighting ability mould reduce the importance of b adge size for the outcome of conflicts in favour of traits most direct ly associated with fighting ability. In two of five replicates, signif icant relationships were found between components of body size and dom inance rank, but in opposite directions. The relationship between badg e size and dominance rank was consistently positive, but non-significa nt. In a pooled sample of the three independent replicates, badge size was the best predictor of dominance, and no other variable explained any variance in dominance. However, the coefficient of determination w as low and linearity of dominance hierarchies was poor. We therefore s uggest that individual recognition may influence the dominance relatio nships.