Abstract:
The size and pattern of a primate home range depends basically on the availability of distribution of
food, the density of the group, free-ranging species and geographical factors. When considering
about Sri Lankan primates; Sri Lanka is home to five primate species. Three species belongs to
catarrhines, the toque monkey (Macaca sinica), the purple-faced langur (S. vetulus), the grey langur
(S. priam thersites) and two or more species of the slender loris (Loris spp.). This study was
conducted in Mihinthale wildlife sanctuary and focused on the home range of the toque monkey
(Macaca sinica sinica), the purple-faced leaf langur (S. vetulus philbrick), and the grey langur (S.
priam thersites). Preliminary observations were started from January 2015 to May of 2015. Intensive
data collection was started from May 2015 to September, 2016. Behavioural observations were
conducted for 136 days. Three groups were selected randomly to represent all three species for this
long term study. Home range data was collected by observations of daily path range of the three
species. To determine the actual home range of the three species GPS points and hard copies of maps
of the site were used. GIS maps were created to illustrate the area used by each species. The results of
the home range sizes of each species indicated that the purple-faced –leaf langur’s home range is the
largest among the three species. All macaque groups have a minimum home range when compare
with the other two langur species. Macaques mainly depend on human-supplied food and hardly
depend on the food from the forest, hence recording the smallest home range among the three primate
species. The study concludes that purple - faced leaf langur’s home range is the largest home range
than gray langur and toque macaque. Gray langur’s home range is larger than toque macaques and
smaller than purple-faced leaf langur. Toque macaque has the smallest home range. The identified
two main factors for this difference are the availability of food and the density of groups in the given
area.
