Survey of Carnivore Species in Selected Thailand Reserves and Evidence for Competitive Exclusion by Larger Carnivores
Abstract
Many species of carnivores occur within Thailand including representatives of the families Felidae, Canidae, Ursidae, Mustelidae, Viverridae and Herpestidae, but there is limited understanding of their natural history, ecology and distribution. Unfortunately many of these species are now threatened or endangered making conservation efforts an important focus in this region. Ecosystem conservation places importance on interactions within a community. Exploitation interactions (predator-prey) have been the focus of many studies within the past decades; however, little attention has been focused on interspecific competition among predators. The aim of this research is to understand interspecific competition among carnivore species that are found within Thailand’s protected area system through both in situ and ex situ data collection and analysis. Ex situ data collection used captive animals to observe possible interspecific competition interactions among tigers (Panthera tigris), leopards (Panthera pardus), and clouded xi leopards ( eofelis nebulosa) using sympatric species feces as a treatment and recording the animals behavior. Increased investigative behaviors were observed for conspecific treatments and similar sized sympatric species. Avoidance behaviors were observed to increase in similar sized sympatric species. In situ data collection used camera traps placed in four protected areas within Thailand. Presence-absence data were collected for all carnivore species detected and used in the program PRESENCE using a 2-species cooccurrence model to investigate interactions. Dyads when species do not overlap in weight were found to co-occur when prey for both species were detected (ϕ >1). When prey species were not detected there was evidence of avoidance by one or both species (ϕ <1). In dyads when the species overlapped in weight the species acted independently of each other when prey were not detected (ϕ =1) or co-occurred when prey were detected. Evidence for species interspecific competition was seen in both in situ and ex situ research techniques. This study’s focus on understanding interspecific competition among carnivore species in Southeast Asia brings us a step closer to providing better input into management decisions. We have evidence for cascading interactions among the three largest cat species in Southeast Asia and we know the impacts that prey species have on the occupancy and interactions of common carnivore species in the wild. These results can be built on and aid in the conservation and preservation of carnivore species in Southeast Asia.
Description
Keywords
Carnivores, Southeast Asia, Thailand