Stallion Mate Choice and Mare Sexual Behaviour in a Herd of Sorraia Horses ( Equus caballus )

Abstract

We examined the relationship between male mate choice, female sexual behaviour, and individual factors in a managed group of Sorraia horses. The herd comprised 9–11 adult mares and their foals. Two stallions were introduced into the mare group in different years for pasture breeding. Mare receptivity during oestrus was poorly correlated with individual factors. Stallions did not prefer to mate with mares that showed the greatest behavioural receptivity during oestrus. The older and more experienced stallion preferred to mate with the older, higher-ranking, or barren oestrous mares. The younger stallion preferred to mate with the more genetically related mares and showed higher oestrus discrimination of mares to who he kept proximity during oestrus. Mate choice was not associated with probability of foaling in the following year. The differential influence of individual factors on mate choice between the stallions could stem from differences in breeding experience and familiarity with the mares.