Biology Reference
In-Depth Information
should be considered, but should not be thought of as the sole solution in
every context.
Methods of population control have included trapping, relocation, culling,
and sterilization programs. Singapore is one of the few countries that is trans-
parent in population control efforts, and thus we are able to learn from their
management efforts (see Box 12.2). They regularly use trapping to remove
nuisance macaques from the population (Sha
et al
.,
2009a
), and have culled
local populations, such as in the 1970s in the Botanical Gardens. Culling has
also been widely used in attempts to entirely remove macaques from Ngeaur
Island in Palau (Wheatley, Chapter 10). In Malaysia, recent efforts to amelior-
ate conflict in the Selangor province around Kuala Lumpur included trapping
and culling of a large proportion of the estimated 250,000 macaques in the
region (Md-Zain
et al
., Chapter 4).
In an effort to reduce direct killing of macaques in Southeast Asia, ster-
ilization has been proposed as a means to stop or lessen population growth
and reduce human-macaque conflict. Authorities in Hong Kong have put the
most effort into sterilization programs (Box 12.1; Wong and Chow,
2004
) and
experimental sterilization programs have also been implemented in Singapore
(Box 12.2) and in Palau (Wheatley, Chapter 10). Currently, Thailand is work-
ing on a sterilization program in Lopburi (Bunluesilp,
2009
; Malavijitnond
et al
., Chapter 5), and there are efforts to use sterilization to manage the
large macaque problem in Selangor in Malaysia (Md-Zain
et al
., Chapter 4).
Although an attractive management approach because it does not result in the
direct killing of animals, there are no systematic long-term studies on steriliza-
tion programs and their effects on human-macaque conflict. Without objective
and rigorous monitoring, the efficacy of sterilization as a management tool
is undetermined. Data on the effects of sterilization programs on populations
needs to be accessible so that stakeholders can access information to inform
strategy-making and decisions.
Macaque sterilization programs must consider numerous factors, most
notably that macaque
distribution
, not population size, is the main driver of
human-macaque conflict. Macaques have long life spans, and after steriliza-
tion they will stay in their location and continue to be in conflict with humans.
Reduction in numbers of individuals may only minimally reduce interspecies
conflict because a group of 20 macaques has the potential to be as damaging
as a group of 40 macaques living in the same space. Other factors to consider
are that the goals and outcomes of the sterilization program must be clearly
defined prior to the initiation of the program. For example, if the goal is to
maintain a certain population size, then that must be clearly articulated so that
there are no expectations that sterilization will completely remove all conflict.
Sterilization programs can be successful at maintaining set population sizes,
