Risky movements? Natal dispersal does not decrease survival of a large herbivore

Natal dispersal is assumed to be a particularly risky movement behavior as individuals transfer, often long distances, from birth site to site of potential first reproduction. Though, because this behavior persists in populations, it is assumed that dispersal increases the fitness of individuals despite the potential for increased risk of mortality. The extent of dispersal risk, however, has rarely been tested, especially for large mammals. Therefore, we aimed to test the relationship between dispersal and survival for both males and females in a large herbivore. Using a radio-transmittered sample of 398 juvenile male and 277 juvenile female white-tailed deer (Odocoileus virginianus), we compared survival rates of dispersers and non-dispersers. We predicted that dispersing deer would experience greater overall mortality than philopatric deer due to direct transfer-related risks (e.g., vehicular collision), indirect immigration-related mortality attributable to colonization of unfamiliar...出生扩散（natal dispersal）被视为一类高风险的移动行为：个体通常需长距离移动，从出生位点转移至潜在的首次繁殖位点。尽管该行为在种群中持续存在，但学界普遍认为，尽管扩散存在增加死亡风险的可能，其仍可提升个体的适合度。然而，扩散行为的风险程度却极少得到验证，针对大型哺乳动物的相关研究尤为匮乏。因此，本研究旨在检验某大型植食性动物的扩散与存活率之间的关联，分别针对雄性与雌性个体展开分析。本研究依托398只经无线电标记（radio-transmittered）的幼年雄性白尾鹿（Odocoileus virginianus）与277只幼年雌性白尾鹿样本，对比了扩散个体与留守个体的存活率。我们预测，扩散白尾鹿的整体死亡率将高于留守个体，这一差异源于扩散相关的直接转移风险（例如车辆碰撞），以及因进驻陌生生境所引发的间接迁入相关死亡……