Primate-parasite interactions in a semi-arid environment

Primate-parasite ecology is a burgeoning field but relatively little is known about parasitism in primates occupying extreme environments. I combined physiological, environmental, behavioural and parasite data to investigate the correlates of infection in wild vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa. I aimed to assess whether our well-established assumptions about primate-parasite interactions hold true in the context of severe ecological stress and how these external stressors may impact how monkeys respond to infection. I found that environmental conditions were the primary drivers of parasitism in the population, with individual-level characteristics playing a diminished role. I also found that while there were links between aspects of behaviour and parasitism, ecological conditions constrained behavioural flexibility. These results highlight the difficulty of generalising across primate populations, and point to the importance of expanding primate-parasite ecology to include animals in more extreme environments. Doing so will allow them to serve as a window into how animals confront climate change-induced environmental changes.The Leakey Foundation (Franklin Mosher Baldwin Memorial Fellowship), the Natural Sciences and Engineering Research Council of Canada, the University of Lethbridge, South Africa’s National Research Foundation and the Canada Research Chairs Program

Sick and tired : sickness behaviour, polyparasitism and food stress in a gregarious mammal

Although sickness behaviour in response to non-lethal parasites has been documented in wild animals, it remains unclear how social and environmental stress might also shape an animal’s behavioural response to parasitism, nor do we know whether simultaneous infection with more than one parasite changes the way animals respond. Here, we combine physiological, environmental, behavioural and parasite measures to investigate behavioural responses to infection in wild vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa. We quantified both activity budget and behavioural predictability to investigate the occurrence of sickness behaviour and infection with two non-lethal gastrointestinal parasite genera. Higher parasite load was linked to an increase in the time spent resting. However, the nature of the relationship with other behaviours was contingent on both the parasite genus in question and parasite species interacted, highlighting the importance of considering co-infection. Overall, food availability was the dominant predictor of behavioural change suggesting that, for monkeys living in a more extreme environment, coping with ecological stress may override the ability to modulate behaviour in response to other physiological stressors. Our findings provide insight into how animals living in harsh environments find ways to cope with parasite infection, avoidance and transmission. SIGNIFICANCE STATEMENT : Sickness behaviour is a suite of behaviours that occur in response to infection that may serve as an adaptive response to cope with infection. For wild animals, the ability to express sickness behaviour will be modulated by the presence of other competing stressors. Hence, the patterns shown are likely to be more complex than under captive conditions, which is where most of our knowledge of sickness behaviour comes from. Using physiological, environmental, behavioural and parasite measures, we demonstrate that although vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa do exhibit sickness behaviours, this is contingent on the parasite genus in question. Further, food availability was the dominant predictor of behavioural change suggesting that, for monkeys living in a more extreme environment, coping with severe ecological stress may override the ability to express sickness behaviour in an adaptive fashion.National Research Foundation (South Africa), Natural Science and Engineering Research Council of Canada (NSERC) Discovery Grants, the Canada Research Chairs Program, a Leakey Foundation Franklin Mosher Baldwin Memorial Fellowship and a Senior Post-doctoral Fellowship at the University of Pretoria.http://link.springer.com/journal/265hj2022Mammal Research Institut

Data for: What you have, not who you know: food-enhanced social capital and changes in social behavioural relationships in a non-human primate

<p>Social network position in non-human primates has far-reaching fitness consequences. Critically, social networks are both heterogenous and dynamic, meaning an individual's current network position is likely to change due to both intrinsic and extrinsic factors. However, our understanding of the drivers of changes in social network position is largely confined to opportunistic studies. Experimental research on the consequences of <em>in situ, </em>controlled<em> </em>network perturbations is limited. Here we conducted a food-based experiment in rhesus macaques to assess whether allowing an individual the ability to provide high-quality food to her group changed her social behavioural relationships. We considered both her social network position across five behavioural networks, as well as her dominance and kin interactions. We found that gaining control over a preferential food resource had far-reaching social consequences. There was an increase in both submission and aggression centrality and changes in the socio-demographic characteristics of her agonistic interaction partners. Further, we found that her grooming balance shifted in her favour as she received more grooming than she gave. Together, these results provide a novel, preliminary insight into how <em>in situ</em>, experimental manipulations can modify social network position and point to broader network-level shifts in both social capital and social power.</p><p>Funding provided by: United States Army Research Office<br>Crossref Funder Registry ID: https://ror.org/05epdh915<br>Award Number: W911NF-13-1-0340</p><p>Funding provided by: Defense Advanced Research Projects Agency<br>Crossref Funder Registry ID: https://ror.org/02caytj08<br>Award Number: W911NF-17-1-0077</p><p>Funding provided by: NIH Office of the Director<br>Crossref Funder Registry ID: https://ror.org/00fj8a872<br>Award Number: R24 OD011136</p><p>Funding provided by: NIH Office of the Director<br>Crossref Funder Registry ID: https://ror.org/00fj8a872<br>Award Number: P51-OD01107</p><p><strong>Data collection:</strong></p> <p>Data were collected on a single group of Rhesus macaques. Behavioural observations were conducted all adult individuals (3+ years) in the group. Affiliative and agonistic interactions were recorded.</p> <p><strong>Data processing:</strong></p> <p>Behavioural observations were used to construct a weighted, directed behavioural network for each of the following behaviours, for both baseline and experimental phases separately: (1) dyadic aggressive interactions where aggressive behaviour was met with a clear submissive response, (2) approach – move away interactions, such as displacements, (3) SBT signals in response to peaceful approaches (note: peaceful SBTs may be accompanied by other submissive behaviours including turn away, move away. or rump present), and (4) social grooming interactions. Weighted, undirected networks were constructed for huddling/social contact and proximity interactions. For directed behaviours, indegree, outdegree (the number of adjacent edges to each node), and strength (total number of interactions) were calculated, while degree centrality was calculated for undirected networks.</p> <p>Dominance ranks were calculated from agonistic interactions for all adult individuals using the Perc package.</p&gt

What you have, not who you know: food-enhanced social capital and changes in social behavioural relationships in a non-human primate

Social network position in non-human primates has far-reaching fitness consequences. Critically, social networks are both heterogeneous and dynamic, meaning an individual's current network position is likely to change due to both intrinsic and extrinsic factors. However, our understanding of the drivers of changes in social network position is largely confined to opportunistic studies. Experimental research on the consequences of in situ, controlled network perturbations is limited. Here we conducted a food-based experiment in rhesus macaques to assess whether allowing an individual the ability to provide high-quality food to her group changed her social behavioural relationships. We considered both her social network position across five behavioural networks, as well as her dominance and kin interactions. We found that gaining control over a preferential food resource had far-reaching social consequences. There was an increase in both submission and aggression centrality and changes in the socio-demographic characteristics of her agonistic interaction partners. Further, we found that her grooming balance shifted in her favour as she received more grooming than she gave. Together, these results provide a novel, preliminary insight into how in situ, experimental manipulations can modify social network position and point to broader network-level shifts in both social capital and social power

What you have, not who you know: food-enhanced social capital and changes in social behavioural relationships in a non-human primate

Social network position in non-human primates has far-reaching fitness consequences. Critically, social networks are both heterogeneous and dynamic, meaning an individual's current network position is likely to change due to both intrinsic and extrinsic factors. However, our understanding of the drivers of changes in social network position is largely confined to opportunistic studies. Experimental research on the consequences of in situ, controlled network perturbations is limited. Here we conducted a food-based experiment in rhesus macaques to assess whether allowing an individual the ability to provide high-quality food to her group changed her social behavioural relationships. We considered both her social network position across five behavioural networks, as well as her dominance and kin interactions. We found that gaining control over a preferential food resource had far-reaching social consequences. There was an increase in both submission and aggression centrality and changes in the socio-demographic characteristics of her agonistic interaction partners. Further, we found that her grooming balance shifted in her favour as she received more grooming than she gave. Together, these results provide a novel, preliminary insight into how in situ, experimental manipulations can modify social network position and point to broader network-level shifts in both social capital and social power