behavior

This study used a continuous focal sampling method with a sampling time of 10 minutes per individual to measure behavior (Martin & Bateson 2012). This means one individual at the time is observed while noting down the exact duration of one type of behavior for 10 minutes straight. When the sampling time is over the next individual was observed. One observation of the whole group takes 50 minutes. Observations of the entire group were done three times per day. The first two observations were done from 10:00-12:00 and the last one after the feeding time (ca. 12:00-14:00). The observation times were chosen because of the need to be present during the feeding time, and periods with the highest behavioral complexity as well as the time when the spider monkeys most likely to defecate. Because of the variable feeding time the time of the observations are also slightly variable. The observations took place around five days per week. Five types of behaviors were observed: possible stereotypic, obviously stereotypic, group size and social behavior (appendix 4). Possible stereotypic behavior for example scratching can be stereotypic but it can also be normal behavior. Obvious stereotypic behavior is always stereotypic for example gnashing the teeth. The preference of the location of the spider monkeys determined the location of the observer.本研究采用连续焦点取样法（continuous focal sampling method），以每只个体10分钟的取样时长开展行为观测（Martin & Bateson 2012）。该方法要求单次仅观测1只个体，连续记录单类行为的精确持续时长，总时长为10分钟。单只个体的取样结束后，随即切换至下一只个体开展观测。完整观测整个猴群需耗时50分钟，每日需完成3次全群体观测：前两次观测时段为10:00至12:00，第三次则安排在饲喂结束后（约12:00至14:00）。选取上述观测时段，是为了覆盖饲喂时段、行为复杂度最高的时段，以及蜘蛛猴最易排便的时段。由于饲喂时长存在波动，实际观测时段亦存在小幅变动。观测活动每周开展约5天。本次共记录5类行为：潜在刻板行为、明确刻板行为、群体规模与社会行为（附录4）。以抓挠为例，潜在刻板行为既可能属于刻板行为范畴，也可能为正常行为；明确刻板行为则均属于刻板行为，例如咬牙。观测者的站位需根据蜘蛛猴的栖息偏好位置确定。