动物学

来源出版物：Current Zoology, 2015, 61(5): 802-810联系邮箱：Eliana PINTUS, pintus@af.czu.cz

封面介绍：Photo of an adult reindeer male during the breeding season in Lapland. Polygynous males, like reindeer, can change their mating tactics across lifetime, but information is scarce on the flexibility of this trait within a given season and the relative costs and benefits of using different tactics. The study shows that reindeer males may switch between the harem-defense and the sneaking tactics throughout the same breeding season as a function of their condition and probably of their relative chances with respect to rivals. The ability to switch between mating tactics can provide higher mating payoffs than just using the least demanding tactic.

Flexible mating tactics and associated reproductive effort during the rutting season in male reindeer (Rangifer tarandus, L. 1758)

Eliana PINTUS, Stefania UCCHEDDU, Knut H. RØED, et al.

Polygynous males can change their mating tactics across their lifetime, but information is scarce on the flexibility of this trait within a given season and the relative costs and benefits of using different tactics. Here, we monitored individually marked male reindeerRangifer tarandusand classified their mating tactics as harem-defense, sneaking, or mixed. The costs of the male reproductive effort were assessed using both direct (i.e. percentage of body mass lost) and indirect measures (i.e. activity patterns such as feeding, standing, and walking), while mating group size and reproductive success were recorded as mating effort benefits. Our results show that reindeer males may switch between the harem-defense and sneaking tactics throughout the same breeding season, providing further support to the notion that reproductive tactics are flexible in ungulates. The costs and benefits of male mating effort vary according to the mating tactic, reaching the highest values in harem-holders and the lowest values in sneaking males. Moreover, males who switched between the sneaking tactic and the harem-defence tactic tended to achieve higher mating success than males who consistently used the least costly tactic. Indeed, all harem-holders successfully sired offspring, whereas only two out of three mixed-tactic males sired one calf, and sneaking males did not sire any calves. In conclusion, our results show that reindeer males can modulate their mating efforts during the same breeding season by switching between the most costly harem-defense tactic and the least costly sneaking tactic, suggesting individual solutions to the balance between reproductive effort and mating opportunities.

alternative mating tactics; intraspecific variation; phenotypic flexibility; polygynous ungulate; sexual behaviour