<P> The wild Asian water buffalo, and on various islands related dwarf species of Bubalus such as anoa were once widespread in Southeast Asia; nowadays the domestic Asian water buffalo is common across the region, but its remaining relatives are rare and endangered . </P> <P> The mouse deer, a small tusked deer as large as a toy dog or cat, mostly can be found on Sumatra, Borneo (Indonesia) and in Palawan Islands (Philippines). The gaur, a gigantic wild ox larger than even wild water buffalo, is found mainly in Indochina . There is very little scientific information available regarding Southeast Asian amphibians . </P> <P> Birds such as the peafowl and drongo live in this subregion as far east as Indonesia . The babirusa, a four - tusked pig, can be found in Indonesia as well . The hornbill was prized for its beak and used in trade with China . The horn of the rhinoceros, not part of its skull, was prized in China as well . </P> <P> The Indonesian Archipelago is split by the Wallace Line . This line runs along what is now known to be a tectonic plate boundary, and separates Asian (Western) species from Australasian (Eastern) species . The islands between Java / Borneo and Papua form a mixed zone, where both types occur, known as Wallacea . As the pace of development accelerates and populations continue to expand in Southeast Asia, concern has increased regarding the impact of human activity on the region's environment . A significant portion of Southeast Asia, however, has not changed greatly and remains an unaltered home to wildlife . The nations of the region, with only few exceptions, have become aware of the need to maintain forest cover not only to prevent soil erosion but to preserve the diversity of flora and fauna . Indonesia, for example, has created an extensive system of national parks and preserves for this purpose . Even so, such species as the Javan rhinoceros face extinction, with only a handful of the animals remaining in western Java . </P>

Eastern russia is considered part of southeast asia