Topcats and underdogs: intraguild interactions among three apex carnivores across Asia's forestscapes

Abstract

Intraguild interactions among carnivores have long held the fascination of ecologists. Ranging from competition to facilitation and coexistence, these interactions and their complex interplay influence everything from species persistence to ecosystem functioning. Yet, the patterns and pathways of such interactions are far from understood in tropical forest systems, particularly across countries in the Global South. Here, we examined the determinants and consequences of competitive interactions between dholes Cuon alpinus and the two large felids (leopards Panthera pardus and tigers Panthera tigris) with which they most commonly co‐occur across Asia. Using a combination of traditional and novel data sources (N = 118), we integrate information from spatial, temporal, and dietary niche dimensions. These three species have faced catastrophic declines in their extent of co‐occurrence over the past century; most of their source populations are now confined to Protected Areas. Analysis of dyadic interactions between species pairs showed a clear social hierarchy. Tigers were dominant over dholes, although pack strength in dholes helped ameliorate some of these effects; leopards were subordinate to dholes. Population‐level spatio‐temporal interactions assessed at 25 locations across Asia did not show a clear pattern of overlap or avoidance between species pairs. Diet‐profile assessments indicated that wild ungulate biomass consumption by tigers was highest, while leopards consumed more primate and livestock prey as compared to their co‐predators. In terms of prey offtake (ratio of wild prey biomass consumed to biomass available), the three species together harvested 0.4–30.2% of available prey, with the highest offtake recorded from the location where the carnivores reach very high densities. When re‐examined in the context of prey availability and offtake, locations with low wild prey availability showed spatial avoidance and temporal overlap among the carnivore pairs, and locations with high wild prey availability showed spatial overlap and temporal segregation. Based on these observations, we make predictions for 40 Protected Areas in India where temporally synchronous estimates of predator and prey densities are available. We expect that low prey availability will lead to higher competition, and in extreme cases, to the complete exclusion of one or more species. In Protected Areas with high prey availability, we expect intraguild coexistence and conspecific competition among carnivores, with spill‐over to forest‐edge habitats and subsequent prey‐switching to livestock. We stress that dhole–leopard–tiger co‐occurrence across their range is facilitated through an intricate yet fragile balance between prey availability, and intraguild and conspecific competition. Data gaps and limitations notwithstanding, our study shows how insights from fundamental ecology can be of immense utility for applied aspects like large predator conservation and management of human–carnivore interactions. Our findings also highlight potential avenues for future research on tropical carnivores that can broaden current understanding of intraguild competition in forest systems of Asia and beyond.

Native prey, not landscape change or novel prey, drive cougar (Puma concolor) distribution at a boreal forest range edge

“…There is intraguild predation and competition between cougars and mesopredators, such as coyote ( Canis latrans ) and lynx ( Lynx canadensis ; Engebretsen et al., 2021 ), and, due to the limitations of our sample size and detections, we did not include these species as the effects of these relationships can be difficult to parse apart. However, we provide here the basis for future studies to consider biotic interactions of multiple trophic levels (Srivathsa et al., 2023 ; Trainor et al., 2014 ), or explore alternative metrics for predator and prey activity across landscapes, to better understand and make predictions about cougar occurrence (Engebretsen et al., 2021 ). Here, we used relative activity indices which are comprised of the number of independent detections of a species divided by the number of active camera days, at a particular site.…”

“…However, we provide here the basis for future studies to consider biotic interactions of multiple trophic levels (Srivathsa et al, 2023;Trainor et al, 2014), or explore alternative metrics for predator and prey activity across landscapes, to better understand and make predictions about cougar occurrence (Engebretsen et al, 2021). Here, we used relative activity indices which are comprised of the number of independent detections of a species divided by the number of active camera days, at a particular site.…”

Carnivore coexistence without competition: giant otters are more nocturnal around dens than sympatric neotropical otters

“…Competition between sympatric carnivores (Order Carnivora) has been widely reported ( Perera-Romero et al, 2021 ; Smith, Erb & Pauli, 2023 ; Srivathsa et al, 2023 ); however, sympatric otter species appear to coexist without direct competition ( Kruuk, 2006 ). Otters, therefore, provide an ideal group to examine how coexistence is facilitated among potential competitors.…”