The effects of maternal presence on natal dispersal are seasonally flexible in an asocial rodent
The effects of maternal presence on natal dispersal are seasonally flexible in an asocial rodent
复制标题
DOI：
10.1007/s00265-015-1920-2
复制
发表时间：
2015-07-01
影响因子：
2.3
通讯作者：
Koshimoto, Chihiro
中科院分区：
文献类型：
--
作者：
Sakamoto, Shinsuke H.;Eto, Takeshi;Koshimoto, Chihiro
在哺乳动物中，雌性的社会宽容是在后代断奶后，通过近亲之间持续的身体接近而形成的。然而，持续密切联系的好处可能会被当地资源竞争和近亲繁殖风险等成本所抵消。我们假设，对于“博爱型雌性”来说，一种灵活的倾向，无论是出生分散还是博爱，都是对社会条件变化的重要行为反应。我们用一种非社会性啮齿类动物，阿波demus speciosus来检验这一点，阿波demus speciosus有两个独立的繁殖季节，一个在春天，第二个在秋天。在这两个季节，女儿和母亲在断奶时都把彼此视为亲人。在春天，一些母鼠繁殖两次，一些第一胎的女儿在同一季节成熟和繁殖。然而，在秋天，只有母熊繁殖，没有第二胎。在春季，母亲不在的断奶后代中，出生分散者的比例高于母亲不在的断奶后代；而在秋季，母亲不在的断奶后代中，出生分散者的比例高于母亲不在的断奶后代。幼崽比母崽更早散去。仅凭人口密度不足以解释这些模式。我们认为，不同程度的雌性亲属之间的生殖竞争导致了雌性出生分散的季节性差异。繁殖条件受环境因素的调节，春季雌性繁殖活动的促进可能导致子代的出生分散，而秋季繁殖活动的抑制可能导致亲缘关系。
In mammals, social tolerance among females, the philopatric sex, is formed through continued physical proximity between kin after offspring are weaned. However, the benefits of continued close association may be outweighed by costs such as local resource competition and risk of inbreeding. We hypothesized that for 'philopatric females', a flexible tendency towards either natal dispersal or philopatry is an important behavioral response to changes in social conditions. We examined this using an asocial rodent, Apodemus speciosus, which exhibits two discrete breeding seasons, one in spring and the second in autumn. Daughters and mothers were shown to recognize each other as kin at the time of weaning in both seasons. In spring, some mothers reproduced twice, and some first-litter daughters matured and reproduced in the same season. In autumn, however, only mothers reproduced, and there were no second litters. In spring, the proportion of natal dispersers was higher among weaned offspring whose mother remained present than those whose mother was absent, while in autumn, natal dispersal was more frequent when the mother was absent than when she remained. Sons dispersed earlier than their female littermates. Population density alone is insufficient to explain these patterns. We suggest that variable levels of reproductive competition between female kin result in seasonal differences in female natal dispersal. Breeding condition can be modulated by environmental factors, and the promotion of reproductive activity of females in spring may cause natal dispersal of daughters, while the inhibition of reproductive activity in autumn may permit philopatry.