Stokes Helena, Perera Vijitha, Jayasena Nilmini, Silva-Fletcher Ayona
Royal Veterinary College, London, United Kingdom.
Department of Wildlife Conservation, Elephant Transit Home, Udawalawe, Sri Lanka.
Zoo Biol. 2017 Jul;36(4):261-272. doi: 10.1002/zoo.21360. Epub 2017 Jun 27.
Many animals exhibit circadian variation in behavior; thus, studying nocturnal behavior is important to fully understand species activity patterns. The nocturnal behavior of Asian elephants, and specifically calves, has received little previous study. We carried out observational study of the nocturnal behavior of orphaned Asian elephant calves at three age groups: "infant" (0-24 months), "young juvenile" (25-36 months) and "old juveniles" (over 36 months). Project aims were to build a nocturnal activity budget, to investigate key age differences, and whether calves exhibited synchronous behavior patterns. We carried out focal animal sampling and instantaneous group scan sampling on 34 calves for 18 nights using an infra-red camera. Focal results indicated that calves spent the highest percentage of scans in lying rest (46.2%) and feeding (28.4%). There was no significant difference between lying rest in the three age groups. Calves spent the majority of time within 5 m of their nearest neighbor, with infants remaining in closest proximity to conspecifics compared to older calves. Synchronous behavior could not be proved statistically but two distinct lying rest periods between 2300 and 0100, and 0330 and 0530, were noted. We found that calves spent more time in lying rest than previously observed in adult elephants. Activity patterns observed suggest that the orphaned group behavior is similar to that reported in the wild and captive zoological collections, and appears to be in concordance with "natural" behavior patterns, a defining feature of animal welfare. This research provides valuable data as a preliminary study.
许多动物的行为都表现出昼夜节律变化；因此，研究夜间行为对于全面了解物种的活动模式很重要。亚洲象，尤其是幼象的夜间行为，此前鲜有研究。我们对三个年龄组的孤儿亚洲象幼象的夜间行为进行了观察研究：“婴儿期”（0 - 24个月）、“幼年前期”（25 - 36个月）和“幼年后期”（36个月以上）。项目目标是建立夜间活动预算，调查关键的年龄差异，以及幼象是否表现出同步行为模式。我们使用红外摄像机对34头幼象进行了18个晚上的焦点动物抽样和即时群组扫描抽样。焦点结果表明，幼象在躺卧休息（46.2%）和进食（28.4%）方面花费的扫描时间百分比最高。三个年龄组在躺卧休息方面没有显著差异。幼象大部分时间都在距离最近邻居5米范围内，与年龄较大的幼象相比，婴儿期幼象与同种个体的距离最近。同步行为在统计学上无法得到证实，但注意到在23:00至01:00以及03:30至05:30之间有两个明显的躺卧休息时间段。我们发现幼象躺卧休息的时间比之前观察到的成年象要多。观察到的活动模式表明，孤儿群体的行为与在野外和圈养动物园中报道的行为相似，并且似乎与“自然”行为模式一致，这是动物福利的一个决定性特征。这项研究作为初步研究提供了有价值的数据。
