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.
