Wild carnivore habitat use and community ecology in a biodiversity hotspot and human-wildlife conflict with pumas and dogs across Chile

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Date

2021-05-21

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Virginia Tech

Abstract

Habitat loss and fragmentation and human-wildlife conflicts, often resulting in retaliatory killing in response to livestock predation, are one of the main threats to wild felids worldwide, including pumas (Puma concolor). However, mesocarnivores are more abundant than large carnivores, live closer to human settlements, and drive community structure and processes in similar or different ways from large predators. Understanding both large and small carnivores' habitat use is key to their conservation and management. Thus, there is need to explore the ecological roles of predators (including invasive ones like free-ranging dogs [Canis lupus familiaris] and cats [Felis catus]) to examine how ecological context modulates the ecological roles of carnivores . This is especially important in my study area, which was severely burned by a catastrophic mega-wildfire in 2017.

I used dynamic occupancy modeling of human-wildlife conflict (HWC) across 52 provinces for 8 years in Chile and found that free-ranging dogs outpace pumas in livestock depredation, killing substantially more livestock than pumas. Occupancy models show that HWC occurrence for both dogs and pumas increased with sheep density. Unexpectedly, dog HWC decreased with anthropogenic habitat degradation indicating that dogs may travel far to prey on livestock. The emergence of puma HWC in a site where it did not occur in the previous year was positively associated with anthropic disturbance. Countrywide, dogs HWC occurrence probability was higher than pumas in 43 out of the 49 provinces where both species occurred. I discuss livestock vulnerability, management strategies, and policy to mitigate HWC, and also highlight threats that free-ranging dogs pose to biodiversity conservation and even human public health.

I also used single-species, single-season occupancy models fit to camera-trap data to investigate the patterns of site occupancy and response to mega-wildfires of native mesocarnivores in southern-central Chile: guignas (Leopardus guigna), culpeo foxes (Lycalopex culpaeus) and chilla foxes (Lycalopex griseus). I found that vulnerable guignas avoided burned sites, preferring sites with native, dense vegetation while culpeo foxes were intermediate in being able to use plantations, but avoiding burned sites. Chilla foxes were most tolerant to landscape change with no response to burns and were found closer to human habitation and rivers.

Finally, I used two-species, single season occupancy models, and Kernel Density Estimation on circular data, to investigate the spatial and temporal dynamics, and overlap of native and exotic carnivores. I found that feral cats are a potential threat to pumas, guignas, and native foxes given they overlap extensively in time of activity with these species. Also, feral dogs had the widest distribution of all species indicating that their effects could be ubiquitous on the landscape. Thus, exotic species are damaging to wildlife, to livestock industry, and even to public health. I urge dialog between government authorities, wildlife managers, and scientists to generate a legal and public policy framework to properly managing habitat and HWC in southern-central Chile.

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Keywords

carnivores, mesocarnivores, habitat use, human-wildlife conflict, mega-wildfires

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