A review of the management measures of feral macaques in Hong Kong

Abstract

Macaques are valuable assets with conservation importance, which provides numerous benefits in ecological, economic and cultural aspects. Nevertheless, they also cause nuisances to humans worldwide including aggressive behavior, crop raiding, zoonotic disease transmission and adverse impacts on the environment. A number of management measures has been implemented such as population control and translocation. In Hong Kong, the authority currently implements diversion i.e. feeding ban and population control by reducing fertility i.e. contraceptive program as major macaque management measures.

This study aimed to review and evaluate the macaque management measures in Hong Kong i.e. feeding ban and contraceptive program, with emphasis on macaque population dynamics, human-macaque interactions, human provisioning and macaque nuisance cases received by the authority. Macaque population data was retrieved from previous literatures and reports. Human-macaque interactions and human provisioning were studied by observations at four prime areas of these interactions. Number of macaque nuisance cases was obtained from the authority.

It was found that feeding ban was effective in controlling human provisioning. The number of feeders and quantity of provisioned food monthly dropped by 91.3% and 90.5% respectively, after 15-year implementation of feeding ban. However, it seems not effective in reducing population growth and aggressive behaviors of macaques. On the other hand, population control by large-scale contraceptive program, which was launched in 2008, was found effective. The macaque abundance in surveyed heterosexual groups was reduced by 9.6% between 2010 and 2012 while proportion of juveniles and infants decreased to 37% in 2012 from 50% in 2010. Besides, there was steady decrease in macaque birth rate from 68.9% in 2008 to 30.2% in 2012. In addition, the number of nuisance cases received also shows a decreasing trend after implementation of contraceptive program.

A total of 756 human-macaque interactions were observed during 128 hrs observation. The rate of human-macaque interactions and macaque aggressive behavior are 5.91 and 0.89 interactions per hour respectively. Both rates are not at high level when compared to the overseas studies. Over 87% of all human-macaque interactions occurred in the context of feeding. It implies that alteration in human behavior toward macaques such as not feeding them could reduce most of the human-macaque interactions in Hong Kong.

This study concludes that feeding ban and contraceptive program are effective in controlling human provisioning and macaque population respectively. However, human-macaque interactions including aggressive behaviors cannot be reduced and eliminated, thus posing a risk of zoonotic disease transmission between human and macaque. Law enforcement should be strengthened to further eradicate human provisioning and prevent physical contact with macaques. Further researches should be carried out to study zoonotic disease from macaques and macaque ecology such as ranging behavior. More importantly, more public education and public participation are indispensable to successful macaque management in Hong Kong.