Behaviour 2019
Sickness Behaviour, Food stress and Polyparasitism in a Gregarious Mammal
Rosemary Blersch1,2, S.Peter Henzi1,2, Tyler Bonnell1, Louise Barrett1,2, Christopher Young1,2,3, Andre Ganswindt3. 1University of Lethbridge, Lethbridge, Alberta, Canada; 2University of South Africa, Florida, , South Africa; 3University of Pretoria, Pretoria, , South Africa

Sickness behaviour in response to non-lethal parasites has been documented in the wild, however, it is still unclear how environmental and social stress, and co-infection might also contribute to an animal’s behavioural response to parasitism. We explored behavioural responses to infection in wild vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa. We collected 581 faecal samples from 27 individuals and analysed them for gastrointestinal parasite prevalence and intensity. We quantified both activity budget and behavioural predictability to investigate the occurrence of sickness behaviour linked to two non-lethal nematode genera. Higher parasite load was linked to an increase in the time spent resting. However, changes in other behaviours was dependent on both the parasite genus in question and how 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.