Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Michelle Thorn is active.

Publication


Featured researches published by Michelle Thorn.


South African Journal of Wildlife Research | 2009

Estimating Brown Hyaena Occupancy Using Baited Camera Traps

Michelle Thorn; Dawn M. Scott; Matthew Green; Philip W. Bateman; Elissa Z. Cameron

Conservation and management of brown hyaenas (Hyaena brunnea) is hampered by a lack of information on abundance and distribution, which is difficult and labour-intensive to obtain. However, occupancy surveys offer a potentially efficient and robust means of assessing brown hyaena populations. We evaluate the efficacy of camera trapping for estimating brown hyaena occupancy, and the effect of environmental variables and lures on detection probability. We estimated population density in Pilanesberg National Park, South Africa, at 2.8/100 km2, occupancy at 1.0 and model-averaged detection probability at 0.1. Using a fish lure increased detection probability to 0.2 and significantly increased encounter rates. We also found that brown hyaenas are more likely to be detected in areas of scrub or woodland rather than grassland. Our results suggest that 13 camera sites would be needed to achieve an occupancy estimate with S.E. of 0.05, and a minimum of 16–34 sampling occasions (with and without the fish lure) should be used in comparable study areas. We conclude that camera trapping is a viable method of estimating brown hyaena occupancy at local and landscape scales and capture—recapture analysis is also possible at a local scale.


African Zoology | 2009

An assessment of diet overlap of two mesocarnivores in the North West Province, South Africa

Ingrid van der Merwe; Craig J. Tambling; Michelle Thorn; Dawn M. Scott; Richard W. Yarnell; Matthew Green; Elissa Z. Cameron; Philip W. Bateman

We used scat analysis to study the diet of two sympatric medium-sized carnivores: brown hyaena and black-backed jackal, in the North West Province of South Africa. Seven major dietary categories were identified from the scats, with mammal remains being most common for both species. Brown hyaena scats contained more large mammal remains, which together with the presence of invertebrates (in 50% of all brown hyaena scats), suggests that they mainly scavenged. Jackal scats contained a higher proportion of small mammal remains, suggesting that jackals actively hunted more often than brown hyaenas did. The diets differed significantly between the two species, even though diet overlap was fairly high (0.79). Further analysis, albeit based on small sample sizes, suggests that diet of these mesopredators differ between protected reserves with apex predators and unprotected areas without apex predators, thus confounding generalizations. Further studies are therefore required to investigate possible mesopredator release when apex predators are absent.


South African Journal of Wildlife Research | 2010

Comparative efficacy of sign surveys, spotlighting and audio playbacks in a landscape-scale carnivore survey

Michelle Thorn; Matthew Green; Philip W. Bateman; Elissa Z. Cameron; Richard W. Yarnell; Dawn M. Scott

Many carnivores are difficult and labour-intensive to detect, often leading to prohibitively high effort and cost in large-scale surveys. However, such studies provide Information that is Important for effective management and conservation. Here, we evaluate the suitability of three survey methods for landscape-scale multi-species monitoring. We compare sign surveys, spotlighting, and audio playbacks in terms of detection efficiency, precision, effort, and cost. Sign surveys out-performed the other methods in all comparison criteria, although supplementary methods were needed for some species and sites. We found that using established analysis techniques, robust landscape-scale abundance estimates would require unrealistically high effort and cost. Occupancy estimation required considerably lower sample sizes and was therefore more economical. We conclude that sign-based occupancy estimates constitute a versatile and efficient option for future large-scale, multi-species carnivore surveys.


Oryx | 2011

Large-scale distribution patterns of carnivores in northern South Africa: implications for conservation and monitoring

Michelle Thorn; Matthew Green; Mark Keith; Kelly Marnewick; Philip W. Bateman; Elissa Z. Cameron; Dawn M. Scott

Accurate assessment of carnivore population status is frequently hindered by insufficient distribution data. For northern South Africa we address this deficit by mapping new records from landscape-scale sign surveys, questionnaire interviews, problem animal records and camera trapping. The black-backed jackal Canis mesomelas and caracal Caracal caracal remain common and wide- spread. Ranges of the serval Leptailurus serval and brown hyaena Hyaena brunnea were much larger than previous estimates, reducing the risk of simultaneous extirpation across all occupied locations. The proportion of range area occupied was larger for several species, notably the leopard Panthera pardus , cheetah Acinonyx jubatus and serval. We conclude that the serval continues to recover from historical threats and is expanding into new areas. A larger brown hyaena range and less fragmented pattern of occurrence probably confers greater resilience to threats than was suggested by previous data. Reduced extinction risk arising from the increased area occupied by the cheetah and leopard is tempered by probable local range contraction. Our maps provide baseline information for monitoring the distribution of these six species, which is essential in managing ecological issues that have a spatial component such as responses to changing land use. Our results also demonstrate the utility of detection/non- detection surveys in rapid assessment of carnivore populations at large spatial scales.


Oryx | 2015

Determinants of attitudes to carnivores: implications for mitigating human–carnivore conflict on South African farmland

Michelle Thorn; Matthew Green; Kelly Marnewick; Dawn M. Scott

Human–wildlife conflict is increasingly prevalent, particularly in relation to carnivores in non-protected areas of Africa. Quantifying the attitudes of land owners towards carnivores and understanding the factors that influence these attitudes are instrumental in conservation planning and reducing persecution-related threats to carnivores.However, information about attitudes to carnivores in Africa, and South Africa in particular, is scarce. To obtain such data we interviewed 170 commercial game and livestock farmers in two ecologically important rural areas of northern South Africa. Responses to statements about carnivore management, stock protection and predationwere generally positive. However, 62% of respondents believed carnivores to be financially damaging and 35% thought them overly abundant. Many respondents (41%) were unwilling to tolerate even low levels of predation and considered persecution of carnivores to be the cheapest form of stock protection (31%). Attitudes were significantly more positive among respondents who did not kill carnivores than among those who did. Generalized linear regression coupled with informationtheoretic analysis showed that attitudes to carnivores were determined by a combination of cultural and land-use attributes more than by economic factors such as stock holdings or predation losses. The results elucidate potential targets for mitigation activities and facilitate the development of communication, education and extension activities specifically designed to appeal to intended recipients and address prevalent motives for persecuting carnivores.


South African Journal of Wildlife Research | 2009

Estimating brown hyaena occupancy using baited camera traps: research article.

Michelle Thorn; Dawn M. Scott; Matthew Green; Philip W. Bateman; Elissa Z. Cameron

Conservation and management of brown hyaenas (Hyaena brunnea) is hampered by a lack of information on abundance and distribution, which is difficult and labour-intensive to obtain. However, occupancy surveys offer a potentially efficient and robust means of assessing brown hyaena populations. We evaluate the efficacy of camera trapping for estimating brown hyaena occupancy, and the effect of environmental variables and lures on detection probability. We estimated population density in Pilanesberg National Park, South Africa, at 2.8/100 km2, occupancy at 1.0 and model-averaged detection probability at 0.1. Using a fish lure increased detection probability to 0.2 and significantly increased encounter rates. We also found that brown hyaenas are more likely to be detected in areas of scrub or woodland rather than grassland. Our results suggest that 13 camera sites would be needed to achieve an occupancy estimate with S.E. of 0.05, and a minimum of 16–34 sampling occasions (with and without the fish lure) should be used in comparable study areas. We conclude that camera trapping is a viable method of estimating brown hyaena occupancy at local and landscape scales and capture—recapture analysis is also possible at a local scale.


Biological Conservation | 2012

What drives human–carnivore conflict in the North West Province of South Africa?

Michelle Thorn; Matthew Green; Fredrik Dalerum; Philip W. Bateman; Dawn M. Scott


Biological Conservation | 2011

Brown hyaenas on roads: Estimating carnivore occupancy and abundance using spatially auto-correlated sign survey replicates

Michelle Thorn; Matthew Green; Philip W. Bateman; Stephen Waite; Dawn M. Scott


Biodiversity and Conservation | 2013

Characteristics and determinants of human-carnivore conflict in South African farmland

Michelle Thorn; Matthew Green; Dawn M. Scott; Kelly Marnewick


Archive | 2014

Determinantsofattitudestocarnivores:implications for mitigating human-carnivore conflict on South African farmland M ICHELLE T HORN ,M ATTHEW G REEN ,K ELLY M ARNEWICK and D AWN M. S COTT

Michelle Thorn; Dawn M. Scott; Matthew Green; Kelly Marnewick

Collaboration


Dive into the Michelle Thorn's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Matthew Green

Mammal Research Institute

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kelly Marnewick

Endangered Wildlife Trust

View shared research outputs
Top Co-Authors

Avatar

Richard W. Yarnell

Nottingham Trent University

View shared research outputs
Top Co-Authors

Avatar

Craig J. Tambling

Nelson Mandela Metropolitan University

View shared research outputs
Top Co-Authors

Avatar

Mark Keith

University of Pretoria

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge