印度喜马拉雅山区西藏盘羊的警戒行为

在几个动物类群中开展的许多行为研究中发现,个体的警觉水平与群体大小存在着负相关关系。一般认为,这种关系是由于个体在一个较大的群体中被捕杀的概率小。在本研究中,我研究了濒危的印度喜马拉雅地区西藏盘羊(Ovis ammon hodgsoni)的警戒行为与群体大小和逃逸地形的关系。我假设小群体中的、位于悬崖旁的盘羊比那些大群体中的、开阔地带(逃逸地形)中的盘羊的警戒水平高。结果发现随着群体增大,盘羊的警戒水平下降,但是,逃逸地形与盘羊的警戒水平没有关系。盘羊的不同性别、年龄组之间的时间预算存在显著差异。与雄性和亚成年个体比较,雌性用于警觉的时间多,它们比雄性采食时间长,移动少。因此,警戒行为是是盘羊的一种重要反捕食行为

Vigilance behavior of the Tibetan argali Ovis ammon hodgsoni in the Indian Trans-Himalaya

An inverse relationship between individual vigilance level and group size is widely reported in many behavioral studies on animals across several taxa. It is generally held that such a relationship is due to a reduced probability of an individual being killed in larger groups. In the present investigation, I studied the vigilance behavior of the endangered Tibetan argali Ovis ammon hodgsoni in relation to group size and escape terrain. I hypothesized that an individual argali has a higher vigilance level in smaller groups and in habitats closer to cliffs than individuals living in larger groups and open areas (escape terrain). The results show that the vigilance of argali decreased with increasing group size, but there was no effect of escape terrain on its vigilance behavior. There were significant differences between age-sex groups: male, female and yearling in their time budgets. Females, compared to males and yearlings, spent more time being vigilant. They also foraged more and moved less than males. It is suggested that vigilance is an important anti-predator behavior amongst argali sheep.