Report: Damages to farmland and crops from Assamese macaque (Macaca assamensis) can be managed by controlling specific group utilising the area as its home range, according to a pilot study report to mitigate human wildlife conflict in western Bhutan.

The report launched in October this year also states that providing monkeys with human related food is not a good idea since they could get habituated to human food. This, in turn, could result in turning the species to crop raiders. “The dependence or attractiveness of human-related food strongly affected the home range use by the monkeys,” the report stated.

Research Development Centre at Yusipang conducted the report over a period of two years from 2012 to 2013. As per the report an ecology and behaviour of Assamese macaque was studied to explore counter measures against agricultural crop damage from the monkeys in western Bhutan.

A total of four monkeys in two different groups from Chuzom and Lebchi in Wangchu valley were captured and collared with very high frequency (VHF) and GPS collar to follow their movements. The groups lived in neighbouring areas.

The study found that the two groups of macaque were also attracted to vendor areas where they could collect leftovers. For instance, the monkeys from two different study areas were found venturing to areas where vendors sold foods and vegetables by the highway.

“Management of human food wastes, provisioned food, crop residues as well as agricultural crop is important to avoid monkey becoming habituated to human food,” the report stated.

But since some studies have indicated in the past that the crop damage can also be highly influenced by availability of natural food in their habitat, the report recommended a study in future on effect of availability of natural food to crop damage.

Assamese macaque is a member of sinica species group, which is distributed widely from Nepal, northern India along the foot of Himalayan mountain range. But monkey with wild boar and elephants are among the notorious of the wild animals causing serious damages to agricultural crops.

It is also the most serious pest among the six species of primates including golden langur, slow loris and capped langur. Assamese macaque according to farmers across the country is the top most daytime crop raider.

The report also stated crop damages from wild animals has resulted in many famers giving up agriculture and migrating to urban areas in search of menial job opportunities.

The results of the study indicated that movement and demography of monkeys were strongly influenced by various food resources. “Due to the stable and fixed nature of the home range size of the monkeys, the agricultural damage in areas can be prevented or minimized through manipulation of their home range use,” the report stated. “For instance, the farmers can avoid losing their crops by knowing when the monkeys raided their fields, which in the case of Chuzom began from August to November while in Lebchu, it is raided in February and March. The Chuzom group also raided potato fields in the month of May.”

The study also found that the monkeys consumed plants for food and changed their food habits with change in seasons.

The study stated that it is important to study the movement of other groups in particular area before attempting to drive away the macaque since it could affect other groups sheltering in the  same area. “Conservation of natural vegetation particularly those preferred by the species must be conserved since availability of natural food can have huge influence on crop damage,” the report stated. “Conservation of natural vegetation particularly preferred by monkey can reduce crop damage.”

The study also recommended further in-depth research in the behaviour of the monkeys around the farmland besides conducting studies in ecology and behaviour to understand the mechanism of crop damage.

RDC Yusipang conducted the study in collaboration with Kyoto University and forestry and forest products research institute, Japan.

Tempa Wangdi