A recently published study has uncovered disturbing information regarding the survival of orangutans in Kalimantan, Indonesia.
In addition to facing habitat loss due to forest exploitation, hundreds of orangutans are intentionally killed every year by people who live within the orangutan’s distribution range.
Killing a ‘major threat’ to wild orangutans
The killing of orangutans is a “major threat”, according to a comprehensive study involving 687 villages from three Kalimantan provinces.
Based on interview surveys conducted between April 2008 and September 2009, researchers found that at least 750 – and possibly as many as 1,790 – orangutans were killed during the year preceding the study.
It was also estimated that thousands of orangutans had been killed in previous years.
These results give rise to two ranges: between 750 and 1790 for the number of orangutan killed in the last year; between 1970 and 3100 for the average number of orangutan killed per year in the orangutan’s 2004 distribution range in Kalimantan within the lifetime of the respondents.
Although the primary reason for killing orangutans was reported at the village level as “for food”, a significant percentage (41%) of the respondents themselves said they had “personally killed” an orangutan for an “unknown reason” and only 14% of the respondents claimed to have killed an orangutan for food. (One respondent even admitted to killing 100 orangutans.)
Conservationists are extremely concerned that between 375 and 1550 of the orangutans killed in 2007 – 2008 were females, which has grave implications for the future.
These mortality rates caused by hunting alone are higher than the theoretical maximum mortality for population viability, suggesting that unless they can be reduced most Kalimantan populations will go extinct.
Unsurprisingly, the interviews revealed that the killing rates were highest among people who “regularly entered the forest for logging or hunting” and that the killings occur in certain “hotspots”.
These hotspots seem to be influenced by land use and proximity to forest, with the highest killing rates in relatively intact forests at higher altitude.
Erik Meijaard, who led the study, recently told The Guardian that Indonesian authorities seem unconcerned with the orangutan situation.
So far in the entire history of orangutan conservation, I think only two people in Indonesia have ended up in jail because of illegal activities related to orangutans.
A detailed report about the orangutan survey can be found here.
Source: Meijaard E, Buchori D, Hadiprakarsa Y, Utami-Atmoko SS, Nurcahyo A, et al. (2011) Quantifying Killing of Orangutans and Human-Orangutan Conflict in Kalimantan, Indonesia. PLoS ONE 6(11): e27491. doi:10.1371/journal.pone.0027491
Photo: Orangutan with her baby via Shutterstock