Copulatory behaviour and paternity in the American kestrel:the adaptive significance of frequent copulations

The adaptive significance of repeated withinpair copulations is not well understood. We analysed thecopulatory behaviour of 16 pairs of solitary-nesting American kestrels, Falco sparverius, in southernQuebec (Canada), and the achieved reproductive success (paternity) of 21 kestrel families determined byDNA fingerprinting, in terms of four hypotheses. (1) The paternity assurance hypothesis, which suggeststhat males copulate frequently to avoid being cuckolded, was rejected because there were few extrapaircopulation attempts (<1% of all copulations observed), withinpair copulations were not timed during thefertile period and mate attendance did not increase as the fertile period approached. (2) The immediatematerial benefits hypothesis, which suggests that females trade copulations for food, was refuted becausecopulations most often occurred without food transfers, especially outside the fertile period.

M. VILLARROEL, D. M. BIRD and U. KUHNLEIN, ANIMAL BEHAVIOUR, 1998, 56, 289-299