Browsing by Author "Wilkinson, Anita"

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    Spatial distribution and intensity of snare poaching in the Boland region of South Africa: implications for optimising anti-poaching efforts
    (2021) Kendon, Tamar A; O'riain, Justin; Wilkinson, Anita; Naude, Vincent N
    The human population of sub-Saharan Africa is growing exponentially, increasing anthropogenic impacts on natural resources, including wildlife, both inside and outside of protected areas. The rising demand for cheap sources of protein is fuelling the harvesting of bushmeat. In South Africa, illegal wire-snares are the most popular method of bushmeat harvesting. However, snare poaching is indiscriminate and inhumane, causing the death of many non-target species and suffering by all animals captured. The impacts of snaring on an ecosystem can be devastating, yet few studies have explored wire-snare poaching trends in southern Africa or on private agricultural lands. This study used data obtained during 210 snare patrols to investigate the intensity of use and spatial distribution of wire-snares across 111 private agricultural properties in the Boland region in the Western Cape province, South Africa. I considered the influence of social and ecological attributes on property-level snare use, including punitive measure enforcement, the employment of seasonal workers, farmer residency, the use of legal lethal control measures, the number of families on the property, property size, the proportion of natural land, and primary agricultural output. I also considered the influence of anthropogenic structures and abiotic variables on snare placement across the landscape, including elevation, fine-scale land-use types, slope, ruggedness, and distance to the nearest street, river, servitude area, farm boundary, and protected area. Wire-snares were largely placed close to the ground, along game trails and fence lines, and anchored to trees and fence posts. My findings reveal that snare use was higher on properties where the farmer lived permanently on the property (P = 0.005) or the primary agricultural output was orchards (P = 0.043). Snares were more likely to be present further from a public street but within roughly 1 km, close to rivers, at an elevation of 300 to 500 m, and in patches of forest plantations, wetlands, bare ground, and natural woody vegetation. There was also a strong interaction (interaction size = 116.56) between distance to street and proximity to a protected area. The predicted snare hotspots are centred around protected areas at mid-elevation (300-500 m) but are not remote in terms of distance to a public street. It is important to use these findings to inform anti-snaring efforts as wire-snare poaching is likely to be a growing threat to local biodiversity. Future studies should use questionnaires or structured interviews in conjunction with field studies to collect data on snare use. This will help to prevent the misleading interpretation of respondent claims, avoid respondent biases and improve targeted snare removal and law enforcement actions. It will also provide insight into the local context, crucial for identifying potential local drivers of snaring, such as food security, and informing the focus of awareness campaigns.
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    Tails through time: leopard population dynamics in the Little Karoo
    (2024) Steyn, Lawrence; Williams, Kathryn; Distiller, Gregory; Hofmeyr, Sally; Mann, Gareth; Wilkinson, Anita
    Large carnivores play a vital role in structuring our ecosystems, yet they face mounting threats such as habitat loss, prey reduction and persecution. These threats reduce their global distribution and impacts their population numbers. Protected areas can offer refuge for large carnivores, however leopards (Panthera pardus), can persist outside of these areas and often occupy mixed-use landscapes. Our understanding of how leopards persist over time in mixed-use landscapes is limited, especially in the semi-arid regions of southern Africa. This study, to the best of my knowledge, is the only multi-session maximum likelihood spatial capture-recapture (SCR) analysis to have been conducted in a semi-arid environment outside of a protected area in Southern Africa. The study aimed to estimate leopard population changes over time and to investigate the possible drivers affecting density, using three surveys (2012, 2017, 2022), in the mixed-use landscape of the Little Karoo in the Western Cape, South Africa. In 2012, a total of 141 paired camera stations were used for a total of 13,050 trap days resulting in 29 unique leopard captures. In 2017, a total of 40 paired camera stations were used for a total of 2,128 trap days resulting in 18 unique leopard captures and in 2022 a total of 64 paired camera stations were used for a total of 8,997 trap days resulting in 37 unique leopard captures. The best performing density model indicated an increasing population trend over the study period which included a trend term on density (D~year) and an interaction term (individual session*sex) on λ0 (capture rate) and σ (spatial decay). Density estimates (Standard Error) for leopard populations for the three surveys 2012, 2017, and 2022, were 0.52 (± 0.11), 0.70 (± 0.08), and 0.95 (± 0.08) leopards per 100 km2, respectively. Terrain ruggedness, elevation, vegetation type and distance from major rivers were all important drivers in leopard density in the Little Karoo. Indicating that high lying areas provide suitable refuge for leopards and are key areas for movement corridor planning. These density estimates are similar to previous single maximum likelihood SCR density estimate studies in the Little Karoo and the Western Cape province. Results from this study indicate the leopards have persisted in the Little Karoo over the study period and suggest that the population may be increasing. Further research on what is driving this population shift is needed, but the results serve as an encouraging sign for leopard conservation in the Little Karoo
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    Open Access
    Tails through time: leopard population dynamics in the Little Karoo
    (2024) Steyn, Lawrence; Williams, Kathryn; Distiller, Gregory; Hofmeyr, Sally; Mann, Gareth; Wilkinson, Anita
    Large carnivores play a vital role in structuring our ecosystems, yet they face mounting threats such as habitat loss, prey reduction and persecution. These threats reduce their global distribution and impacts their population numbers. Protected areas can offer refuge for large carnivores, however leopards (Panthera pardus), can persist outside of these areas and often occupy mixed-use landscapes. Our understanding of how leopards persist over time in mixed-use landscapes is limited, especially in the semi-arid regions of southern Africa. This study, to the best of my knowledge, is the only multi-session maximum likelihood spatial capture-recapture (SCR) analysis to have been conducted in a semi-arid environment outside of a protected area in Southern Africa. The study aimed to estimate leopard population changes over time and to investigate the possible drivers affecting density, using three surveys (2012, 2017, 2022), in the mixed-use landscape of the Little Karoo in the Western Cape, South Africa. In 2012, a total of 141 paired camera stations were used for a total of 13,050 trap days resulting in 29 unique leopard captures. In 2017, a total of 40 paired camera stations were used for a total of 2,128 trap days resulting in 18 unique leopard captures and in 2022 a total of 64 paired camera stations were used for a total of 8,997 trap days resulting in 37 unique leopard captures. The best performing density model indicated an increasing population trend over the study period which included a trend term on density (D~year) and an interaction term (individual session*sex) on λ0 (capture rate) and σ (spatial decay). Density estimates (Standard Error) for leopard populations for the three surveys 2012, 2017, and 2022, were 0.52 (± 0.11), 0.70 (± 0.08), and 0.95 (± 0.08) leopards per 100 km2, respectively. Terrain ruggedness, elevation, vegetation type and distance from major rivers were all important drivers in leopard density in the Little Karoo. Indicating that high lying areas provide suitable refuge for leopards and are key areas for movement corridor planning. These density estimates are similar to previous single maximum likelihood SCR density estimate studies in the Little Karoo and the Western Cape province. Results from this study indicate the leopards have persisted in the Little Karoo over the study period and suggest that the population may be increasing. Further research on what is driving this population shift is needed, but the results serve as an encouraging sign for leopard conservation in the Little Karoo