Singing and mating success in water pipits: one specific song element makes all the difference.

Positive correlations between male vocalization and reproductive success have been documented for many animal species. They are usually based on differences between males in vocalization rate, duration or repertoire size. Here, we present probably the first field study linking differences in territorial overlap and mating status to differences in a single, clearly definable song element, the 'Snarr'. Male water pipits, Anthus spinoletta, with high Snarr scores were mated more often than males with low scores, and their territories overlapped less with those of neighbours. Although correlating positively with male body condition, the frequency of the Snarr did not reflect male age, territory size, territory quality in terms of food and paternal performance. Therefore, it seems unlikely that the higher mating success of males with high Snarr scores results from active female choice of high-quality males; rather, high Snarr scores seem to signal dominance in males. Likely mechanisms that produce the link between vocalization and mating success, and potential costs that prevent some males from producing the Snarr at a higher rate, are discussed. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.