Comparative analysis of vegetation in the habitat of bonobos and chimpanzees using Landsat image.

利用卫星数据和树木的计数普查，我们可以区分出几种类型的植被，包括原生林、次生林和沼泽林。这一信息对黑猩猩和倭黑猩猩的植被利用分析是有用的。通过比较陆地卫星数据和树木普查数据，我们可以估算出无法进行树木普查的那部分原始范围的植被类型。因此，这种方法似乎对那些栖息地范围太大而无法由实际植被普查覆盖的物种的生境利用分析是有用的。我们还开发了一种改进的估算黑猩猩密度的巢穴计数方法。通过这种方法，我们可以在较短的研究时间内准确估计黑猩猩的密度和它们栖息地使用的季节性变化。利用这些方法，我们分析了乌干达Kalinzu森林的黑猩猩、坦桑尼亚的Ugala地区和Lukwa地区，以及刚果民主共和国的Wamba地区和Hongo地区的倭黑猩猩的栖息地利用情况。我们发现，在不同植被类型的地区，黑猩猩和倭黑猩猩的密度有很大差异，而且这些动物在不同的季节会很大程度上改变它们的活动范围。我们还发现，不同植被类型的组合会增加黑猩猩和倭黑猩猩的密度。基于这些信息，我们可以确定影响黑猩猩和倭黑猩猩栖息地利用的一些重要因素，并可以在未来的研究中研究它们栖息地利用的种间和种内差异。在这个研究项目中，我们集中在我们实际访问的地区进行调查。然而，这项使用陆地卫星数据的研究开辟了一种方法，可以在没有实际植被普查的情况下估计更广泛地区的黑猩猩和倭黑猩猩的密度。

By using the landsat data and enumerating census of trees, we could distinguish several types of vegetation, including primary forest, secondary forest, and swamp forest. This information was useful for the analysis of vegetation use of chimpanzees and bonobos. The comparison between the landsat data and tree census enabled to estimate the vegetation type of the part of the home range for which we could not carry out the tree census. Thus this method appeared to be useful for the analysis of habitat use of the species whose home range is too large to cover by the actual vegetation census. We also developed an improved method of nest count for the estimation of density of chimpanzees. By this method, we could estimate accurate density of chimpanzees and the seasonal changes of their habitat use in a shorter period of research. Using these methods, we analyzed the habitat use by chimpanzees in the Kalinzu Forest, Uganda, Ugala area and Lukwa area in Tanzania, and bonobos in Wamba area and Hongo area in Democratic Republic of Congo. We found that the density of chimpanzees and bonobos are much different between the areas with different vegetation types, and that these animals largely shift their home ranges in different seasons. We also found that the combination of different vegetation types in a home range increases the density of chimpanzees and bonobos. Based on these information, we can identify some important factors influencing the habitat use by chimpanzees and bonobos, and can examine the inter and intra-specific differences in their habitat use in future studies. In this study project, we focused on the area where we actually visited and carried out the survey. However, this study using the landsat data opened a way to estimate the density of chimpanzees and bonobos in the wider area without the actual vegetation census.