Mannus Justin O'RIain
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Mannus Justin O'RIain has a total of 497 co-authors. Here are the top co-authors by number of shared publications:
- Nigel Charles Bennett
Mammal Research Institute, Department of Zoology and Entomology University of Pretoria Pretoria South Africa
10 shared publications - Marine Drouilly
Panthera New York New York USA
9 shared publications - Andrew J. King
Biosciences, Faculty of Science and Engineering, Swansea University 2 , Singleton Park, Swansea SA2 8PP, UK
8 shared publications - Anna M. Bracken
School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
8 shared publications D. Gaynor
7 shared publicationsR. Kansky
7 shared publications
Latest Publications
- 22 July 2026
- Published by Springer Nature in International Journal of Primatology
- Vol. 47 (5) , 1177-1195
Within- and Between-Individual Variation in Hair Cortisol Concentrations in Wild Chacma Baboons (Papio ursinus)
- 22 July 2026
- Published by Springer Nature in International Journal of Primatology
- Vol. 47 (5) , 1177-1195
Within- and Between-Individual Variation in Hair Cortisol Concentrations in Wild Chacma Baboons (Papio ursinus)
- Open Access
- 28 October 2024
- Published by The Royal Society in Philosophical Transactions of the Royal Society B: Biological Sciences
- Vol. 379 (1916) , 20220466
Linking energy availability, movement and sociality in a wild primate ( Papio ursinus )
Proximate mechanisms of ‘social ageing’, i.e. shifts in social activity and narrowing of social networks, are understudied. It is proposed that energetic deficiencies (which are often seen in older individuals) may restrict movement and, in turn, sociality, but empirical tests of these intermediary mechanisms are lacking. Here, we study wild chacma baboons ( Papio ursinus ), combining measures of faecal triiodothyronine (fT3), a non-invasive proxy for energy availability, high-resolution GPS data (movement and social proximity) and accelerometry (social grooming durations). Higher (individual mean-centred) fT3 was associated with increased residency time (i.e. remaining in the same area longer), which, in turn, was positively related to social opportunities (i.e. close physical proximity). Individuals with more frequent social opportunities received more grooming, whereas for grooming given, fT3 moderated this effect, suggesting an energetic cost of giving grooming. While our results support the spirit of the energetic deficiencies hypothesis, the directionality of the relationship between energy availability and movement is unexpected and suggests that lower-energy individuals may use strategies to reduce the costs of intermittent locomotion. Thus, future work should consider whether age-related declines in sociality may be a by-product of a strategy to conserve energy. This article is part of the discussion meeting issue ‘Understanding age and society using natural populations’.
- 28 October 2024
- Published by The Royal Society in Philosophical Transactions of the Royal Society B: Biological Sciences
- Vol. 379 (1916) , 20220466
Open AccessLinking energy availability, movement and sociality in a wild primate ( Papio ursinus )
Proximate mechanisms of ‘social ageing’, i.e. shifts in social activity and narrowing of social networks, are understudied. It is proposed that energetic deficiencies (which are often seen in older individuals) may restrict movement and, in turn, sociality, but empirical tests of these intermediary mechanisms are lacking. Here, we study wild chacma baboons ( Papio ursinus ), combining measures of faecal triiodothyronine (fT3), a non-invasive proxy for energy availability, high-resolution GPS data (movement and social proximity) and accelerometry (social grooming durations). Higher (individual mean-centred) fT3 was associated with increased residency time (i.e. remaining in the same area longer), which, in turn, was positively related to social opportunities (i.e. close physical proximity). Individuals with more frequent social opportunities received more grooming, whereas for grooming given, fT3 moderated this effect, suggesting an energetic cost of giving grooming. While our results support the spirit of the energetic deficiencies hypothesis, the directionality of the relationship between energy availability and movement is unexpected and suggests that lower-energy individuals may use strategies to reduce the costs of intermittent locomotion. Thus, future work should consider whether age-related declines in sociality may be a by-product of a strategy to conserve energy. This article is part of the discussion meeting issue ‘Understanding age and society using natural populations’.
- Open Access
- 2 October 2024
- Published by Taylor & Francis in African Zoology
- Vol. 60 (4) , 286-297
The underground cat: burrow use by female black-footed cats ( Felis nigripes )
- 2 October 2024
- Published by Taylor & Francis in African Zoology
- Vol. 60 (4) , 286-297
Open AccessThe underground cat: burrow use by female black-footed cats ( Felis nigripes )
- Open Access
- 7 August 2024
- Published by The Royal Society in Biology Letters
- Vol. 20 (8) , 20240163
More allogrooming is followed by higher physiological stress in wild female baboons
Social bonds increase fitness in a range of mammals. One pathway by which social bonds may increase fitness is by reducing the exposure to physiological stress, i.e. glucocorticoid (GC) hormones, that can be detrimental to health and survival. This is achieved through downregulating hypothalamic–pituitary–adrenal (HPA)-axis activity. Indeed, long-term measures of social (grooming) bonds are often negatively correlated with HPA-axis activity. However, the proximate role of physical touch through allogrooming remains an open question in the sociality–health–fitness debate. Demonstrating the potential anxiolytic benefits of grooming in the wild is hindered by methodological limitations. Here, we match accelerometer-identified grooming in wild female chacma baboons ( Papio ursinus ) to non-invasive faecal GC metabolite concentrations (fGCs). Consistent with previous work, we found a negative (but statistically non-significant) overall relationship between individual averaged fGCs and grooming rates. However, when time-matching grooming to fGCs, we found that both more giving and receiving grooming were followed by higher fGCs. This upregulation of HPA-axis activity suggests that maintaining social bonds (and its ultimate fitness benefits) may come at a shorter-term physiological cost. This finding sheds new light on a ubiquitous social behaviour typically considered ‘relaxing’ and suggests that sociopositive contact can trigger physiological stress.
- 7 August 2024
- Published by The Royal Society in Biology Letters
- Vol. 20 (8) , 20240163
Open AccessMore allogrooming is followed by higher physiological stress in wild female baboons
Social bonds increase fitness in a range of mammals. One pathway by which social bonds may increase fitness is by reducing the exposure to physiological stress, i.e. glucocorticoid (GC) hormones, that can be detrimental to health and survival. This is achieved through downregulating hypothalamic–pituitary–adrenal (HPA)-axis activity. Indeed, long-term measures of social (grooming) bonds are often negatively correlated with HPA-axis activity. However, the proximate role of physical touch through allogrooming remains an open question in the sociality–health–fitness debate. Demonstrating the potential anxiolytic benefits of grooming in the wild is hindered by methodological limitations. Here, we match accelerometer-identified grooming in wild female chacma baboons ( Papio ursinus ) to non-invasive faecal GC metabolite concentrations (fGCs). Consistent with previous work, we found a negative (but statistically non-significant) overall relationship between individual averaged fGCs and grooming rates. However, when time-matching grooming to fGCs, we found that both more giving and receiving grooming were followed by higher fGCs. This upregulation of HPA-axis activity suggests that maintaining social bonds (and its ultimate fitness benefits) may come at a shorter-term physiological cost. This finding sheds new light on a ubiquitous social behaviour typically considered ‘relaxing’ and suggests that sociopositive contact can trigger physiological stress.
- Open Access
- 27 July 2024
- Published by Elsevier in Animal Behaviour
- Vol. 215, 97-109
Intrinsic and extrinsic factors combine to affect baboon movements across natural and urban environments
- 27 July 2024
- Published by Elsevier in Animal Behaviour
- Vol. 215, 97-109
Open AccessIntrinsic and extrinsic factors combine to affect baboon movements across natural and urban environments
- Open Access
- 12 February 2024
- Published by Springer Nature in Scientific Data
- Vol. 11 (1) , 1-17
The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems.
- 12 February 2024
- Published by Springer Nature in Scientific Data
- Vol. 11 (1) , 1-17
Open AccessThe bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems.
- 1 January 2024
- Published by Southern African Wildlife Management Association in African Journal of Wildlife Research
- Vol. 54 (1)
Using Camera-Trapping to Estimate Riverine Rabbit, Bunolagus monticularis, Population Density
African Journal of Wildlife Research is a multidisciplinary journal that has been published since 1971 and covers the scientific, applied, managerial, methodological, and sociological issues related to wildlife research.
- 1 January 2024
- Published by Southern African Wildlife Management Association in African Journal of Wildlife Research
- Vol. 54 (1)
Using Camera-Trapping to Estimate Riverine Rabbit, Bunolagus monticularis, Population Density
African Journal of Wildlife Research is a multidisciplinary journal that has been published since 1971 and covers the scientific, applied, managerial, methodological, and sociological issues related to wildlife research.
- Open Access
- 17 December 2023
- Published by AOSIS in Koedoe - African Protected Area Conservation and Science
- Vol. 66 (1) , 8
Honey badgers in and around Table Mountain National Park, Cape Town
Koedoe - African Protected Area Conservation and Science
- 17 December 2023
- Published by AOSIS in Koedoe - African Protected Area Conservation and Science
- Vol. 66 (1) , 8
Open AccessHoney badgers in and around Table Mountain National Park, Cape Town
Koedoe - African Protected Area Conservation and Science
- Open Access
- 30 June 2023
- Published by Springer Nature in AMBIO
- Vol. 52 (10) , 1635-1649
Small-livestock farmers’ perceived effectiveness of predation control methods and the correlates of reported illegal poison use in the South African Karoo
The use of poison against predators is pervasive and negatively impacts biodiversity and ecosystem health globally. Little is known about the correlates of poison use as a lethal control method on small-livestock farmland. We used a mixed-methods approach to investigate commercial farmers’ experience with and perceived effectiveness of predation control methods, reported poison use and its correlates in the Central Karoo. Farmers perceived lethal methods to be cheaper and more effective than non-lethal methods in protecting their livestock from predation. They reported more experience with lethal methods, and over half reported having used poison. This is higher than other estimates in southern Africa and consistent with other survey-based evidence from the Karoo. Reported poison use was positively related to perceived efficacy, declining on-farm employment and perceived threats of predators. It was negatively related to terrain ruggedness. Our findings provide an understanding of the context and motivations shaping this illegal behavior.
- 30 June 2023
- Published by Springer Nature in AMBIO
- Vol. 52 (10) , 1635-1649
Open AccessSmall-livestock farmers’ perceived effectiveness of predation control methods and the correlates of reported illegal poison use in the South African Karoo
The use of poison against predators is pervasive and negatively impacts biodiversity and ecosystem health globally. Little is known about the correlates of poison use as a lethal control method on small-livestock farmland. We used a mixed-methods approach to investigate commercial farmers’ experience with and perceived effectiveness of predation control methods, reported poison use and its correlates in the Central Karoo. Farmers perceived lethal methods to be cheaper and more effective than non-lethal methods in protecting their livestock from predation. They reported more experience with lethal methods, and over half reported having used poison. This is higher than other estimates in southern Africa and consistent with other survey-based evidence from the Karoo. Reported poison use was positively related to perceived efficacy, declining on-farm employment and perceived threats of predators. It was negatively related to terrain ruggedness. Our findings provide an understanding of the context and motivations shaping this illegal behavior.
- Open Access
On the Fence: The Impact of Education on Support for Electric Fencing to Prevent Conflict between Humans and Baboons in Kommetjie, South Africa
Few studies test whether education can help increase support for wildlife management interventions. This mixed methods study sought to test the importance of educating a community on the use of a baboon-proof electric fence to mitigate negative interactions between humans and Chacma baboons (Papio ursinus) in a residential suburb of the City of Cape Town, South Africa. An educational video on the welfare, conservation and lifestyle benefits of a baboon-proof electric fence was included in a short online survey. The positioning of the video within the survey was randomised either to fall before or after questions probing the level of support for an electric fence. The results showed that watching the video before most survey questions increased the average marginal probability of supporting an electric fence by 15 percentage points. The study also explored whether the educational video could change people’s minds. Those who saw the video towards the end of the survey were questioned again about the electric fence. Many changed their minds after watching the video, with support for the fence increasing from 36% to 50%. Of these respondents, the results show that being female raised the average marginal probability of someone changing their mind in favour of supporting the fence by 19%. Qualitative analysis revealed that support for or against the fence was multi-layered and that costs and concern for baboons were not the only relevant factors influencing people’s choices. Conservation often needs to change people’s behaviours. We need to know what interventions are effective. We show in the real world that an educational video can be effective and can moderately change people’s opinions and that women are more likely to change their position in light of the facts than men. This study contributes to the emerging literature on the importance of education in managing conservation conflicts and the need for evidence-based interventions.
Open AccessOn the Fence: The Impact of Education on Support for Electric Fencing to Prevent Conflict between Humans and Baboons in Kommetjie, South Africa
Few studies test whether education can help increase support for wildlife management interventions. This mixed methods study sought to test the importance of educating a community on the use of a baboon-proof electric fence to mitigate negative interactions between humans and Chacma baboons (Papio ursinus) in a residential suburb of the City of Cape Town, South Africa. An educational video on the welfare, conservation and lifestyle benefits of a baboon-proof electric fence was included in a short online survey. The positioning of the video within the survey was randomised either to fall before or after questions probing the level of support for an electric fence. The results showed that watching the video before most survey questions increased the average marginal probability of supporting an electric fence by 15 percentage points. The study also explored whether the educational video could change people’s minds. Those who saw the video towards the end of the survey were questioned again about the electric fence. Many changed their minds after watching the video, with support for the fence increasing from 36% to 50%. Of these respondents, the results show that being female raised the average marginal probability of someone changing their mind in favour of supporting the fence by 19%. Qualitative analysis revealed that support for or against the fence was multi-layered and that costs and concern for baboons were not the only relevant factors influencing people’s choices. Conservation often needs to change people’s behaviours. We need to know what interventions are effective. We show in the real world that an educational video can be effective and can moderately change people’s opinions and that women are more likely to change their position in light of the facts than men. This study contributes to the emerging literature on the importance of education in managing conservation conflicts and the need for evidence-based interventions.