Cheyne Susan M, Thompson Claire J H, Phillips Abigail C, Hill Robyn M C, Limin Suwido H
Centre for the International Cooperation in Management of Tropical Peatlands, Kampus UNPAR, Tunjung Nyaho, Jalan Yos Sudarso Palangka Raya, Central Kalimantan 73112, Indonesia.
Primates. 2008 Jan;49(1):50-6. doi: 10.1007/s10329-007-0063-0. Epub 2007 Sep 26.
We demonstrate that although auditory sampling is a useful tool, this method alone will not provide a truly accurate indication of population size, density and distribution of gibbons in an area. If auditory sampling alone is employed, we show that data collection must take place over a sufficient period to account for variation in calling patterns across seasons. The population of Hylobates albibarbis in the Sabangau catchment, Central Kalimantan, Indonesia, was surveyed from July to December 2005 using methods established previously. In addition, auditory sampling was complemented by detailed behavioural data on six habituated groups within the study area. Here we compare results from this study to those of a 1-month study conducted in 2004. The total population of the Sabangau catchment is estimated to be about in the tens of thousands, though numbers, distribution and density for the different forest subtypes vary considerably. We propose that future density surveys of gibbons must include data from all forest subtypes where gibbons are found and that extrapolating from one forest subtype is likely to yield inaccurate density and population estimates. We also propose that auditory census be carried out by using at least three listening posts (LP) in order to increase the area sampled and the chances of hearing groups. Our results suggest that the Sabangau catchment contains one of the largest remaining contiguous populations of Bornean agile gibbon.
我们证明，尽管听觉采样是一种有用的工具，但仅靠这种方法并不能真正准确地表明一个地区长臂猿的种群数量、密度和分布情况。如果仅采用听觉采样，我们发现数据收集必须持续足够长的时间，以考虑到不同季节鸣叫模式的变化。2005年7月至12月，我们采用先前确立的方法，对印度尼西亚加里曼丹中部萨邦奥集水区的白颊长臂猿种群进行了调查。此外，我们还通过研究区域内六个习惯化群体的详细行为数据，对听觉采样进行了补充。在此，我们将本研究的结果与2004年进行的一项为期1个月的研究结果进行比较。萨邦奥集水区的总人口估计约有几万只，不过不同森林亚型的数量、分布和密度差异很大。我们建议，未来对长臂猿的密度调查必须包括在发现长臂猿的所有森林亚型中获取的数据，仅从一种森林亚型进行推断很可能会得出不准确的密度和种群估计。我们还建议，通过使用至少三个监听点（LP）来进行听觉普查，以扩大采样面积并增加听到群体的机会。我们的结果表明，萨邦奥集水区拥有婆罗洲白手长臂猿现存最大的连续种群之一。
