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.