Researchers are beginning to have tentative hopes that numbers of a rare black macaque of Indonesia has stopped declining and populations levels are beginning to grow again. A recent study suggests that populations of the Sulawesi black macaques are heading back to levels last seen 20 years ago.
The researchers from the US and Indonesia have been monitoring the levels of black macaques (Macaca nigra) in the Tangkoko Nature Reserve. The macaque is classed as critically endangered by the IUCN. The long-term surveys have been undertaken since 1997. The latest findings have been published in this months edition of American Journal of Primatology.
Lead author and UW research professor of psychology, Randall Kyes, explained “Fifteen years ago it looked like this macaque population would continue its decline and eventually disappear.” While the findings of the new survey is promising he is keen to highlight that success is not yet there, saying that the findings “…doesn’t mean that everything is fine now and that we no longer need to worry about the fate of these animals, but it is good news compared with what we’ve seen over the past 30-plus years in this reserve.”
Tangkoko Nature Reserve in North Sulawesi, Indonesia, is high in biodiversity and a popular location for forest safaris with tourists.
In the survey a section of the forest was visited twice a day and the number of black macaques seen were counted. In the last year of the survey included in the current published study – 2011 – the populations densities and levels of the species were back at levels recorded during surveys of 1994.
The number of groups of macaques per square kilometer (0.40 of a square mile) increased from 3.6 in 1999 to 3.9 in 2005 and to 4.3 in 2011 – in 1994 the number was 3.9 groups per square kilometer.
They observed a similar gradual climb in numbers of individuals per square kilometer: 32.4 in 1999, 53.8 in 2005 and 61.5 in 2011 – in 1994 the number was 68.7 individuals per square kilometer.
There is still along way to go though before numbers of macaques in the forest return to previous levels. In the 1970’s when the species was first studied and surveyed there were 10 groups per square kilometer and 300 individuals per square kilometer.
“We’ve found that the progressive decline has slowed,” Kyes said. “Somewhere over the last 10 years the trend has started to turn. We’re seeing the population in the balance now, but without the sustained efforts by local and international groups working in the reserve and the support and involvement of the local people, the macaques will likely face further decline.”
Co-authors in Indonesia are Entang Iskandar of Bogor Agricultural University’s Primate Research Center; and Jane Onibala, Umar Paputungan and Sylvia Laatung of Sam Ratulangi University. Co-author Falk Huettmann is from the University of Alaska-Fairbanks.
While the findings that were published did not include the impact of the projects outreach work the researchers believe that it’s educational and community work is part of the success of the conservation efforts.
Each year a field course in conservation biology and global health for local university students and the community. The team also supports working with local children by visiting schools. The black macaque is a traditional meal for local residents at a time for celebrations in the same way that some will eat turkey for Christmas or Thanksgiving. Kyes explained that “We don’t chastise them for eating monkeys, but we do explain that there might not be many left in the future. We encourage them to ask their parents if there’s something else they can eat.”
The out-reach work also takes advantage of the popularity of Tangkoko Nature Reserve with tourists. The reserve can be useful for the local economy – but only if the biodiversity of the reserve remains.
American Journal of Primatology. Long-Term Population Survey of the Sulawesi Black Macaques (Macaca nigra) at Tangkoko Nature Reserve, North Sulawesi, Indonesia.