Social contact behaviors are associated with infection status for Trichuris sp. in wild vervet monkeys (Chlorocebus pygerythrus)

Abstract

Social grooming in the animal kingdom is common and serves several functions, from removing ectoparasites to maintaining social bonds between conspecifics. We examined whether time spent grooming with others in a highly social mammal species was associated with infection status for gastrointestinal parasites. Of six parasites detected, one (Trichuris sp.) was associated with social grooming behaviors, but more specifically with direct physical contact with others. Individuals infected with Trichuris sp. spent significantly less time grooming conspecifics than those not infected, and time in direct contact with others was the major predictor of infection status. One model correctly predicted infection status for Trichuris sp. with a reliability of 95.17% overall when the variables used were time spent in direct contact and time spent grooming others. This decrease in time spent grooming and interacting with others is likely a sickness behavior displayed by individuals with less energy or motivation for non-essential behaviors. This study emphasizes the possible links between host behavior and parasitic infections and highlights the need for an understanding of a study population’s parasitic infections when attempting to interpret animal behavior.

Cost and benefits of being social: examining the influence of sociality on faecal parasites in free-ranging rhesus macaques

“…We did not find a relationship between infection risk and grooming interactions, contrasting previous evidence from other systems where this behaviour has been associated with higher infection risk [5,6,7,8]. Yet, we cannot disregard that our reduced sample (e.g., one sample per animal vs multiple samples) and the low prevalence of nematodes in our animals -which are commonly the parasites associated with social contact transmission -explain these results.…”

“…Grooming - a common affiliative behaviour observed in mammals - involves direct social contact and can increase the likelihood of infection by directly transmitted parasites. For example, in Japanese macaques ( Macaca fuscata )[5], spider monkeys Ateles hybridus ) [6], vervet monkeys ( Chlorocebus pygerythrus ) [7] and savannah baboons ( Papio cynocephalus ) [8] individuals with more grooming partners or that engaged more often in grooming interactions were more likely to be infected with nematodes. However, grooming has also been linked to health benefits by directly removing ectoparasites [9, 10].…”

Preliminary assessment of gastrointestinal parasites of the sun‐tailed monkey (Allochrocebus solatus) in a semi‐free‐ranging colony

“…is a parasite with a simple and direct life cycle. This pinworm has been reported in numerous populations of primate across Africa 9,10,12,41,47 and in other regions 45 . Trichuris belongs to the soil‐transmitted helminths, one of the most important groups of infectious agents with a high potential 48,49 .…”

Social interactions do not affect mycoplasma infection in griffon vultures

“…For instance, Japanese macaques (Macaca fuscata fuscata and M. fuscata yakui) that engage more frequently in grooming interactions are more likely to become infected with nematodes (Romano et al, 2016). In addition to social roles, host attributes such as age, can impact infectious status, for example because of the ontogeny of the immune system (Altizer et al, 2004;Lesser et al, 2006;Clark et al, 2017;Wren et al, 2021). For instance, in house finches, and raptors, the prevalence of M. gallisepticum is higher in juveniles than in adults (Altizer et al, 2004;Lierz et al, 2008a;Anglister et al, 2024).…”