Body Guillaume, Weladji Robert B, Holand Øystein, Nieminen Mauri
Department of Biology, Concordia University, Montreal, Quebec, Canada.
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway.
PLoS One. 2014 Apr 23;9(4):e95618. doi: 10.1371/journal.pone.0095618. eCollection 2014.
During the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group's fission probability, instead of inter-harem movement. In this study, we tested whether male herding ability, female mate choice or harassment avoidance influence fission probability. We recorded group dynamics in a herd of reindeer Rangifer tarandus equipped with GPS collars with activity sensors. We found no evidence that the harassment level in the group affected fission probability, or that females sought high rank (i.e. highly competitive and hence successful) males. However, the behavior of high ranked males decreased fission probability. Male herding activity was synchronous with the decrease of fission probability observed during the rut. We concluded that male herding behavior stabilized groups, thereby increasing average group size and consequently the opportunity for sexual selection.
在发情期，雌性有蹄类动物在兽群或领地之间移动，要么是为了挑选配偶，要么是为了避免受到骚扰。雌性可能会被雄性驱赶，可能会与心仪的雄性待在一起，或者聚集在占主导地位的雄性附近，以避免受到其他雄性的骚扰。在裂变 - 融合群体动态中，雌性的移动最好用群体的裂变概率来描述，而不是用兽群间的移动来描述。在本研究中，我们测试了雄性的驱赶能力、雌性的配偶选择或对骚扰的规避是否会影响裂变概率。我们记录了一群佩戴了带有活动传感器的GPS项圈的驯鹿（Rangifer tarandus）的群体动态。我们没有发现证据表明群体中的骚扰水平会影响裂变概率，或者雌性会寻找地位高（即竞争激烈且因此成功）的雄性。然而，地位高的雄性的行为降低了裂变概率。雄性的驱赶活动与发情期观察到的裂变概率的降低同步。我们得出结论，雄性的驱赶行为使群体稳定，从而增加了平均群体规模，进而增加了性选择的机会。
