Effects of divergent migratory strategies on access to resources for Cape buffalo (Syncerus caffer caffer)

Populations of large herbivores frequently display divergent migratory strategies, a likely consequence of the trade-off between the costs and benefits of migration. Globally, physical and environmental barriers disrupt migrations, leading to increased residency, which can have detrimental consequences. In the Okavango Delta, Botswana, veterinary cordon fences erected in 1982 may have caused enforced residency in some subpopulations of Cape buffalo (Syncerus caffer caffer). We used data from GPS-enabled collars fitted to females in 1 resident and 1 migratory subpopulation of buffalo to test the hypotheses that 1) residents have access to less-productive forage than migrants, 2) residents occupy smaller home ranges and live in smaller herds than migrants, 3) reproductive productivity is lower in resident herds, and 4) residents have poorer body condition than migrants. Forage characteristics varied between resident and migrant ranges, both between and within seasons. Reproductive product...大型植食动物种群常表现出差异化的迁徙策略，这一现象大概率源于迁徙行为的成本与收益权衡。全球范围内，物理与环境屏障会干扰迁徙进程，导致种群居留倾向升高，进而引发诸多不利后果。在博茨瓦纳奥卡万戈三角洲，1982年架设的兽医防疫隔离栅栏，可能迫使部分非洲水牛（Syncerus caffer caffer）亚种群转为居留种群。本研究借助佩戴于雌性非洲水牛身上的GPS项圈（GPS-enabled collars）数据，针对1个居留亚种群与1个迁徙亚种群展开分析，以验证四项假说：1）居留种群的可利用草料生产力低于迁徙种群；2）居留种群的家域范围与兽群规模均小于迁徙种群；3）居留兽群的繁殖产出更低；4）居留个体的身体状况逊于迁徙个体。不同季节间及季节内，居留与迁徙种群的栖息区域内草料特征均存在差异。繁殖产出……