Pochron S T
Department of Anthropology, State University of New York at Stony Brook, 11794, USA.
Int J Biometeorol. 2000 Sep;44(3):141-7. doi: 10.1007/s004840000058.
Do free-ranging baboons avoid traveling towards the sun? Sun avoidance, in addition to resource and predator locations, may influence troop movement and non-random use of the home range. This paper investigates how sun avoidance, as measured by facial exposure to sunlight, influences directional choices. It hypothesizes that baboons should avoid the sun in the hot, dry season and show indifference to it in the cool, lush season. This paper also hypothesizes that baboons employ sun-avoidance behaviors more while they forage or travel to resting sites than when they travel to foraging sites or engage in active social behaviors; lastly this paper hypothesizes that sun altitude, temperature, humidity, and cloud cover influence sun-avoidance behavior. Using focal-animal techniques on 21 males from free-ranging baboon troops, I collected locational data, accurate to within 1.6 m, over 15 months. I calculated the difference between baboon bearings and the sun's azimuth in angular degrees. Both linear and circular statistics indicate that baboons put significantly (P<0.01) more than 90 degrees between their bearing and the sun's azimuth under certain conditions. Contrary to hypotheses based on the detrimental effects of insolation, baboons in the cool, lush season avoid the sun, while baboons in the hot, dry season do not. In the lush season, the extent to which baboons avoid the sun does not depend on their other behaviors. Dry-season baboons demonstrate stronger sun avoidance while resting than when engaged in other behaviors. Finally, in the dry season, temperature drives sun avoidance; humidity drives it in the lush season.
自由放养的狒狒会避免朝着太阳行进吗？除了资源和捕食者的位置外，躲避阳光可能会影响群体的移动以及对栖息地的非随机利用。本文研究了通过面部暴露于阳光下所衡量的躲避阳光行为如何影响方向选择。研究假设狒狒在炎热干燥的季节应避免阳光直射，而在凉爽湿润的季节则对阳光无明显偏好。本文还假设，与前往觅食地点或进行活跃的社交行为时相比，狒狒在觅食或前往休息地点时更多地采用躲避阳光的行为；最后，本文假设太阳高度、温度、湿度和云层覆盖会影响躲避阳光的行为。我对自由放养的狒狒群体中的21只雄性狒狒采用焦点动物技术，在15个月内收集了精确到1.6米以内的位置数据。我计算了狒狒行进方向与太阳方位角之间的角度差。线性和圆形统计数据均表明，在某些条件下，狒狒行进方向与太阳方位角之间的夹角显著（P<0.01）大于90度。与基于日照有害影响的假设相反，凉爽湿润季节的狒狒会躲避阳光，而炎热干燥季节的狒狒则不会。在湿润季节，狒狒躲避阳光的程度并不取决于它们的其他行为。干旱季节的狒狒在休息时比在进行其他行为时表现出更强的躲避阳光行为。最后，在干旱季节，温度驱动躲避阳光行为；在湿润季节，湿度驱动该行为。
