Faculty of Global and Regional Studies, University of the Ryukyus, Okinawa, Japan.
Mpala Research Centre, Nanyuki, Kenya.
Am J Primatol. 2021 Jan;83(1):e23223. doi: 10.1002/ajp.23223. Epub 2020 Dec 18.
For diurnal nonhuman primates, shifting among different sleeping sites may provide multiple benefits such as better protection from predators, reduced risk of parasitic infection, and closer proximity to spatially and temporally heterogeneous food and water. This last benefit may be particularly important in sleeping site selection by primates living in savanna-woodlands where rainfall is more limited and more seasonally pronounced than in rainforests. Here, we examined the influence of rainfall, a factor that affects food and water availability, on the use of sleeping sites by anubis baboons (Papio anubis) over two 13-month study periods that differed in rainfall patterns. We predicted that during wet periods, when food and water availability should be higher, the study group would limit the number of sleeping sites and would stay at each one for more consecutive nights than during dry periods. Conversely, we predicted that during dry periods the group would increase the number of sleeping sites and stay at each one for fewer consecutive nights as they searched more widely for food and water. We also predicted that the group would more often choose sleeping sites closer to the center of the area used during daytime (between 07:00 and 19:00) during wet months than during dry months. Using Global Positioning System data from collared individuals, we found that our first prediction was not supported on either monthly or yearly timescales, although past monthly rainfall predicted the use of the main sleeping site in the second study period. Our second prediction was supported only on a yearly timescale. This study suggests that baboons' choice of sleeping sites is fluid over time while being sensitive to local environmental conditions, one of which may be rainfall.
对于昼行性非人类灵长类动物而言，在不同的睡眠地点之间移动可能会带来多种好处，例如更好地免受捕食者的伤害、降低寄生虫感染的风险，以及更接近时空异质的食物和水。对于生活在稀树草原林地中的灵长类动物而言，最后一个好处可能尤其重要，因为这些地区的降雨量比热带雨林更为有限，季节性更强。在这里，我们研究了降雨这一影响食物和水供应的因素对努比亚狒狒（Papio anubis）在两个 13 个月的研究期间使用睡眠地点的影响，这两个研究期间的降雨模式存在差异。我们预测，在食物和水供应较高的湿润期，研究组会限制睡眠地点的数量，并会在每个地点停留更多的连续夜晚，而在干旱期则会相反。相反，我们预测在干旱期，由于它们更广泛地寻找食物和水，该组会增加睡眠地点的数量，并在每个地点停留更少的连续夜晚。我们还预测，该组在湿润月份会更频繁地选择靠近白天（07:00 至 19:00）使用区域中心的睡眠地点，而在干旱月份则不会。使用佩戴项圈个体的全球定位系统数据，我们发现，我们的第一个预测在月度或年度时间尺度上都没有得到支持，尽管过去的月度降雨量可以预测第二个研究期间主要睡眠地点的使用情况。我们的第二个预测仅在年度时间尺度上得到支持。这项研究表明，狒狒对睡眠地点的选择是随时间变化的，同时对当地环境条件敏感，其中之一可能是降雨。
