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. / Doctor of Philosophy / Landscape transformation and human-wildlife conflict (HWC), which often result in retaliatory killing of wildlife in response to livestock predation, is one of the main global threats to wild cats, including pumas (Puma concolor). Medium-sized carnivores (mesocarnivores or mesopredators) are more abundant than large carnivores, live closer to human settlements and, like large predators, impact ecosystem structure and function significantly. Understanding habitat use of these carnivores is key to their conservation and management and to biodiversity preservation. Thus, there is need to investigate the ecological roles of carnivores (including invasive ones like free-ranging dogs and cats) to determine how interactions with other carnivore species and with the physical environment influence ecological roles of such species. This is especially important in my study area, which was severely burned by a catastrophic mega-wildfire in 2017, and for which there is scant information on wildlife responses to the mega-fire.
I determined the distribution and causes of HWC across 52 provinces for 8 years in Chile and found that free-ranging dogs accounted for higher livestock depredation than pumas, killing substantially more livestock. Occurrence of HWC for both dogs and pumas increased with the sheep density of the province. Unexpectedly, dog HWC increased in less degraded habitats, indicating that dogs may travel far to prey on livestock in remote areas. The emergence of puma HWC in a site where it did not occur in the previous year increased with human-caused disturbance. Countrywide, dog HWC was higher than pumas in 43 out of the 49 provinces where both pumas and dogs occurred. I discuss livestock vulnerability, management strategies, and policy changes to address HWC, and discuss the threats that free-ranging dogs pose to biodiversity conservation and even to human public health.
I also used remotely-triggered, camera-trap records to explore distribution of three mesocarnivores (guignas, culpeo foxes and chilla foxes across the landscape and in response to mega-wildfires in southern-central Chile. I found that guignas, a small and vulnerable wild cat, avoided burned sites, preferring sites with native, dense vegetation while culpeo foxes were intermediate in being able to use plantations, but avoiding burned areas. Chilla foxes were most tolerant to landscape change with no response to burns, and they were found closer to human settlements and rivers.
Finally, I examined overlap in space and time of day between native species pairs and native and exotic species pairs. I found that dogs were the most widely distributed species across the landscape, but were mostly diurnal while native species were primarily nocturnal. Cats however had high temporal overlap with guinas and chilla foxes, highlighting the potential for competition between them.. Thus, exotic species are damaging to wildlife, livestock and even human health. I discuss the management implications and 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.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/103440 |
| Date | 21 May 2021 |
| Creators | Osorio Popiolek, Christian Thomaz |
| Contributors | Fish and Wildlife Conservation, Kelly, Marcella J., Karpanty, Sarah M., Wultsch, Claudia, Cherry, Michael J. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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