Incidence of multiple paternity and inbreeding in high-density brown bear populations on the Shiretoko Peninsula, Hokkaido, Japan

Understanding the breeding ecology of a species is essential for the appropriate conservation and management of wildlife. In brown bears, females occasionally copulate with multiple males in one breeding season, which may lead to multiple paternity in a single litter. In contrast, inbreeding, a potential factor in the reduction of genetic diversity, may occur, particularly in threatened populations. However, few studies have reported the frequency of these phenomena in brown bear populations. Here, we investigated the incidence of multiple paternity and inbreeding in a high-density brown bear population on the Shiretoko Peninsula in Hokkaido, Japan. A total of 837 individuals collected from 1998 to 2017 were genotyped at 21 microsatellite loci, and parentage analysis was performed. Out of 70–82 litters with ≥2 offspring, 14.6–17.1% of litters were sired by multiple males. This was comparable to the rate reported in a Scandinavian population, although population density and litter size, ...

深入了解某一物种的繁殖生态学，对野生动物的科学保护与规范化管理至关重要。就棕熊而言，雌性个体在单个繁殖季偶尔会与多只雄性交配，这可能导致同一胎幼崽出现多父本现象（multiple paternity）。与之相对的是，近交（inbreeding）作为引发遗传多样性降低的潜在诱因，可能在种群中发生，尤其在受威胁的种群中更为常见。然而，目前鲜有研究报道棕熊种群中这两类现象的发生频率。本研究针对日本北海道知床半岛的高密度棕熊种群，调查了多父本现象与近交的发生情况。研究对1998年至2017年间采集的837份棕熊样本，基于21个微卫星位点（microsatellite loci）进行了基因分型，并开展亲权分析（parentage analysis）。在70至82窝至少拥有2只幼崽的棕熊窝中，14.6%至17.1%的窝崽由多只雄性共同孕育。该比例与斯堪的纳维亚棕熊种群的报道结果相近，尽管种群密度与幼崽窝大小……