Temporal variation in the operational sex ratio and male mating behaviours in reindeer ( Rangifer tarandus )

摘要: In polygynous species, sexual selection is mostly driven by male ability to monopolize access females in oestrous. ungulates, the operational sex ratio (OSR), i.e. proportion of males individuals ready mate, varies throughout peak rut, resulting from temporal variation number But way adjust their mating tactics maximise oestrous (i.e. as OSR varies) yet be investigated. Using 15 years behavioural observations reindeer (Rangifer tarandus), we compared relative importance time within rutting season (days peak-rut) and explain propensity frequency after controlling for potential encounters) young adult dominant engage four tactics: herding females, chasing other males, investigating female reproductive status, courting females. Male-male agonistic behaviour was most frequent behaviour, followed herding. As predicted, changed over season: first herding, then finally contrast our prediction, did not find support theory. We noted some discrepancies how adjusted during season, adults being more efficient timing performing The reported sequence may than a static tactic oestrous, regardless population composition.