Biology Reference
In-Depth Information
macaques have not overrun Kabaena Island and only range on 25 percent of the
island (Froehlich
et al
.,
2003
), unlike Mauritius or Ngeaur. Moreover, the unique
morphology of these macaques suggests they have been on the island for a long
period of time (Froehlich
et al
.,
2003
) and thus may not be invasive here.
Tinjil Island, West Java, Indonesia
During 1988 through 1991, 58 male and 420 female wild-captured long-tailed
macaques were intentionally released from Sumatra and Java to start a natural
habitat breeding facility on Tinjil Island, located off the south coast of Banten
Province, Java (Kyes,
1993
; Santoso and Winarano,
1992
), with the intention
of managing a sustainable population (Kyes
et al
.,
1998
; Crockett
et al
.,
1996
).
Since long-tailed macaques have become the predominant primate exported for
research purpose (USFW, 2006, see Box 1.2), the breeding colony was started
to assist in supplying this demand, while limiting the strain on natural popula-
tions caused by capturing wild macaques. From 1970, about 15,000 long-tailed
macaques per year were being exported from Indonesia alone (Santosa,
1996
;
Djuwantoko
et al
.,
1993
). When macaques are taken at these large numbers
populations can dramatically plummet, as shown by the 90 percent decline in
rhesus monkeys through the 1960s and 70s in India (Southwick and Siddiqi,
1994
and Chapter 11). Regulations were passed in 1994 by the Indonesian
Forestry Department restricting export of wild-caught primates, and therefore
Tinjil became a major source of legal exports for biomedical lab primates out
of Indonesia (Pamungkasand Sajuthi,
2003
). Furthermore, the colony also
allowed for breeders to control infections carried by macaques, which are safer
to use in biomedical research than wild-caught animals (Pamungkas
et al
.,
1994
). The model was an attempt to make a more environmental-friendly and
healthy alternative to the practice of trapping wild primates for the unstoppable
demand of laboratory primates.
Since their initial release, the macaque-breeding colony has been pro-
visioned, closely monitored, and managed. In 1990, a survey showed the
macaque population was well established and had grown to 760 individuals
(Santoso and Winarno,
1992
). By 1997, the population was reported to have
grown to 1,550 monkeys in eighteen to twenty groups (Kyes
et al
.,
1998
).
At this time, the island population consisted of very large groups (i.e., 78-86
individuals per group), that was later reduced to 30-40 individuals per group
in recent years (Kyes, personal communication). The population is sustained
at this manageable level by periodically harvesting offspring for use in bio-
medical research. Managers remove enough monkeys to prevent overpopula-
tion, but don't remove so many macaques as to disrupt the sustainability of the
