Biology Reference
In-Depth Information
Box 6.1 Recent demographic and behavioral data of
Macaca
fascicularis
at Padangtegal, Bali, Indonesia
F. Brotcorne, I. Nyoman Wandia, Aida L. T. Rompis, I. G. Soma, I.
Nyoman Suartha and M. C. Huynen
We conducted an assessment of the long-tailed macaque population at
Padangtegal Monkey Forest from October to December 2009. In this
study, we documented recent changes in the synanthropic population of
macaques occupying this site, which has a growing tourist interest and is
actively managed by a local village committee. We present the latest trends
in demography, activity and dietary patterns, to compare with previous
data collected by Fuentes
et al
. (this chapter) between 1998 and 2002. We
will then discuss the effects of management strategies on the population
since 2002.
During this study, we collected 181 hours of behavioural data using
20-minute focal sampling of identified individuals belonging to various
age/sex classes. In total, we also performed four population censuses and
20 group counts using two census methods. First, to census the whole
population, observers (i.e., researchers and students from the Universitas
Udayana and volunteer members of the village committee), trained to
identify age/sex classes, were spread in 24 sectors of the Monkey Forest.
Each observer had to count the number of individuals in each age/sex class
present in his respective sector. Second, throughout the study, one obser-
ver counted the groups during collective travels as soon as they crossed
over an open area.
Demography:
The recent census at Padangtegal revealed a marked
increase in the population size, with 498 individuals including 34 adult
males, 39 subadult males, 155 adult females and 270 immatures. This
means the population increased by 59 percent between 2002 and 2009. If
we consider changes in population size since 1986 (
Figure 6.3
), we note
that the population growth was not stable over time. The annual population
growth rate
*
was 11 percent between 1986 and 1992, 12 percent between
1998 and 2003, and rose to 20 percent between 2007 and 2009. The growth
of this population has thus been continuing at a dramatic rate, especially
since 2007, apparently without any population crashes to curb this positive
trend. This growth was related to a change in demographic structure where
the population increased from three groups in 2002 to five groups in 2009.
Based on the groups' ranging patterns reported by Fuentes
et al.
we assume
group 1 and group 2 each split in two groups at some time between 2006
and 2009. The increase in abundance and diversity of food provisioning and
