2016 Volume 4 Issue 1 Pages 35-43
This study examined methodological problems associated with using direct observations to estimate home ranges of wild animals. It also provides preliminary documentation of the behavior and ecology of wild Assamese macaques in Bhutan. We collected group location data using a GPS-collared female and direct observations during April–August 2011. The GPS measured the group's locations every day at scheduled times, and the group was observed 11 days per month, on average. The group primarily used the riverbed and undulating slopes along the river during the daytime. The GPS measurements frequently failed at the midnight sampling time, possibly due to the group's use of steep cliffs as sleeping sites. The steep rock walls of the cliff likely prevented radio transmissions from GPS satellites. GPS indicated monthly home ranges of the group to be between 3.2 and 5.4 km2, close to estimates based on direct observations, except during May. Direct observations greatly underestimated the home range in May, when the range of the group changed dramatically. Observation days should be uniformly allocated throughout the month to avoid such underestimation and accurately estimate monthly home range, especially early in a study when no prior knowledge of the home range exists.
