A Communal Sign Post of Snow Leopards (Panthera uncia) and Other Species on the Tibetan Plateau, China

The snow leopard is a keystone species in mountain ecosystems of Central Asia and the Tibetan Plateau. However, little is known about the interactions between snow leopards and sympatric carnivores. Using infrared cameras, we found a rocky junction of two valleys in Sanjiangyuan area on the Tibetan Plateau where many mammals in this area passed and frequently marked and sniffed the site at the junction. We suggest that this site serves as a sign post to many species in this area, especially snow leopards and other carnivores. The marked signs may also alert the animals passing by to temporally segregate their activities to avoid potential conflicts. We used the Schoener index to measure the degree of temporal segregation among the species captured by infrared camera traps at this site. Our research reveals the probable ways of both intra- and interspecies communication and demonstrates that the degree of temporal segregation may correlate with the degree of potential interspecies competition. This is an important message to help understand the structure of animal communities. Discovery of the sign post clarifies the importance of identifying key habitats and sites of both snow leopards and other species for more effective conservation. 1. Introduction The snow leopard (Panthera uncia), an endangered species listed in IUCN Red List [1], occurs in remote and rugged mountains across Central Asia and the Tibetan Plateau [2]. As a keystone species, this cat has an important role in these mountain ecosystems [3]. But with only an estimated population of 3500–7000 remaining, the snow leopard generally occurs at low densities. Poaching, retaliatory killing due to livestock-snow leopard conflict, decimation of prey, and habitat degradation have all contributed to its rarity [2]. Most studies of snow leopard have focused on its habitat [4, 5] and food habits [6–8], whereas little is known about the interaction of snow leopards and their sympatric species. Olfactory and visual signals are known as crucial mediators for intraspecies communication. Mammals, especially solitary species, use these signals to advertise reproductive status, recognize sex, identify individuals, establish territory and so on [9, 10]. Communal sign posts have, for example, been found in snow leopard [11], giant panda (Ailuropoda melanoleuca) [12], and American black bear (Ursus americanus) [13] habitats. However, previous studies did not describe interspecies interactions at such locations. In this study, we discovered a site sniffed and marked by snow leopards and several other