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PHYSICAL DAMAGE AND ECONOMIC IMPACT OF CROP RAIDING BY
THE BUTON MACAQUE (Macaca ochreata brunnescens)
Aim
To
assess the impact of crop raiding by Buton macaques upon farms, in terms of
physical impact and associated economic losses.
Objectives
1) Monitor any occurrences of crop raiding by macaques
2)
Make general observations on the crop types grown in each farm
3)
Monitor the raids via scan sampling, noting age, sex, class, behaviour
and food consumed
4)
Note any defence systems being used by farmers and their effectiveness
5)
Gather information on the farmers’ perceptions of macaques
Introduction
There are a
total of 19 macaque species worldwide, with six being endemic to Sulawesi. (IUCN
1996) The Buton macaque, Macaca brunnescens, is a sub-species of the
booted macaque, which inhabits the south eastern Sulawesi. Macaques
inhabit primary forests and degraded forests adjacent to crops. Clearing of the
forest to provide farmland exposes poor quality soil, which is soon eroded
becoming unsuitable for agriculture. Unfortunately the removal of the forest
removes the habitat of the macaques who may be dependant upon it for their
survival.
The impacts
of primates on farmers fields is becoming increasingly important as conservation
projects adopt a more integrated approach taking into account the needs and
perceptions of local people as those of the wildlife. The aims as stated in the
objectives are to try and determine any economic losses attributable to Buton
macaques undertaking crop raids in farms surrounding the village of Kawele. If
the macaque populations are to survive it is essential that they are able to do
so alongside the local human populations. This is especially important in areas
such as Indonesia where crops are often relied upon for subsistence purposes.
Methodology
Seven study
farms surrounding Kawele were chosen based on distance to the forest, number of
neighbouring farms, and size. The farms were monitored in rotation. Each farm
was observed for 10 hours from 6:30 am until 4:30 pm. These times were based on
previous work showing that macaques rise at dawn, and are therefore unlikely to
raid before 6:30 am, and in the evening begin moving to a sleep tree between the
times of 3:30 pm until 5:00 pm.
In the field
the following information was recorded:
Three days
were spent at the beginning of the study observing an habituated group of
macaques to familiarise the observer with the macaques and the different age sex
classes. In total the farms were monitored for 24 days. Farms 1,2 and 3 were
observed for four days each, and farms 4,5,6 and 7 for 3 days. These data will
be combined with that collected by two other research students to provide over
nine weeks of observations.
Initial
findings
The crops in
the different fields were raided to varying degrees by Buton macaques. The
number of macaques entering the fields, and their behaviour whilst in the fields
also varied from farm to farm, and from raid to raid. Farms adjacent the forest
that are not bordered by many other farms, were raided most frequently. Sweet
potato was very abundant in all but farms 2 and 7 and was the most frequently
taken crop. Banana, dry rice, pumpkin and papaya leaves were also taken but in
much smaller amounts.
Low, 1m high
surrounded all of the farms, fencing. Whilst this keeps out pigs, it provides no
barrier to raiding macaques. Shouting by people and barking by dogs alone does
not seem to have any effect on monkeys while they are raiding, unless this is
accompanied with movement towards the raiding group in a threatening manner.
Trapping was not widely used in the farms studied. This is likely to be because
traps have a high maintenance demand and over time the monkeys may learn to
avoid them.
Some farmers used poison, Temex, but it is expensive and difficult to obtain. On a farm that previously lost much of a banana crop to crop raiding macaques 11 were found dead from a group of 22 after bananas laced with poison were laid out. Although half the group was killed, the remaining monkeys continued to crop raid, before a larger group moved in to occupy their territory. Poisoning therefore does not work as a deterrent, and typically will have only a short term effect in reducing the local population of macaques.
REPORT
A
report entitled The
physical damage and attributable economic impact of crop raiding by the Buton
macaque (Macaca ochreata brunnescens) on farms in the village of Kawele, Buton
island S. E. Sulawesi will be produced by Adrienne Bennett, University of
Leeds by June 2003.