Do polygynous males of Akodon azarae (Rodentia: Sigmodontinae) vary their mating tactics at low availability of females?

BONATTO FLORENCIA; STEINMANN ANDREA; GOMEZ M DANIELA; PRIOTTO JOSÉ

MAMMALIA

WALTER DE GRUYTER & CO

Lugar: Berlin; Año: 2015 vol. 79

0025-1461

We examined in Akodon azarae if at low availability of females (sex ratio biased towards males, 3:1), mating tactics of males are determined by the number of receptive females to which they have access, or by the number of male competitors with which they interact. To test these hypotheses we measured home range size and overlap degree. At the beginning of the reproductive season, in three enclosure populations, we studied spacing patterns using 57 and 30 home ranges established by reproductive males and females in three enclosure populations. We statistically compared our results with those previously obtained in enclosure populations with a sex ratio 1:1. Male home range sizes were larger than those recorded infor populations with a sex ratio 1:1. The degree of male intra-sexual overlap increased about 3.5 times with respect to that observed under a sex ratio 1:1. The increase in home range sizes and intra-sexual overlap degree of reproductive males reflects that A. azarae males may adjust their spacing strategy in order to increase their mating opportunities at low density of females. Our results suggest that at low breeding female availability male mating tactics could be determined by the number of receptive females to which they have access.