Sickness behaviour associated with non-lethal infections in wild primates

Abstract

Non-lethal parasite infections are common in wildlife, but there is little information on their clinical consequences. Here, we pair infection data from a ubiquitous soil-transmitted helminth, the whipworm (genus Trichuris), with activity data from a habituated group of wild red colobus monkeys (Procolobus rufomitratus tephrosceles) in Kibale National Park, Uganda. We use mixed-effect models to examine the relationship between non-lethal parasitism and red colobus behaviour. Our results indicate that red colobus increased resting and decreased more energetically costly behaviours when shedding whipworm eggs in faeces. Temporal patterns of behaviour also changed, with individuals switching behaviour less frequently when whipworm-positive. Feeding frequency did not differ, but red colobus consumption of bark and two plant species from the genus Albizia, which are used locally in traditional medicines, significantly increased when animals were shedding whipworm eggs. These results suggest self-medicative plant use, although additional work is needed to verify this conclusion. Our results indicate sickness behaviours, which are considered an adaptive response by hosts during infection. Induction of sickness behaviour in turn suggests that these primates are clinically sensitive to non-lethal parasite infections.

The devil is in the details—Host disease and co‐infections are associated with zoonotic pathogen carriage in Norway rats (Rattus norvegicus)

“…Furthermore, the lesions that were associated with L. interrogans were more severe than those associated with B. tribocorum, the latter of which included thyroid goitre and nematode infections. Although we cannot deduce the time sequence in a cross‐sectional study, if these severe lesions occurred prior to L. interrogans infection, they may have led to sickness behaviours that increased the likelihood of pathogen exposure (Bouwman & Hawley, ; Ghai, Fugère, Chapman, Goldberg, & Davies, ; Hart, ). For instance, disease‐related changes to foraging and dominance behaviours may have increased exposure to environmental sources of L. interrogans .…”

Changes in physiological stress and behaviour in semi-free-ranging red-capped mangabeys ( Cercocebus torquatus ) following antiparasitic treatment

“…Energetic trade-offs between resting and foraging are consistent with sickness behaviour, in that parasitized animals favoured low-energy states when infected with parasites. Similarly, red colobus monkeys increased resting behaviour when infected with whipworm [21], and experimentally treated Grant's gazelles (Nanger granti) increased foraging behaviour and decreased vigilance compared with parasitized controls [61].…”

“…Further investigations combining information on food availability, feeding and foraging frequency, and dietary composition in naturally infected wild animals, will be useful in determining if food quality, as opposed to only food quantity, changes in infected versus uninfected individuals. In red colobus monkeys, for example, feeding frequency did not vary with infection status, but whipworm-infected animals shifted dietary composition to include more plants with medicinal properties [21].…”

“…Indeed, behaviours of red colobus monkeys (Procolobus rufomitratus tephrosceles) infected by whipworm (Trichuris spp.) included a shift to less energetically expensive behaviours [21]. In social animals, time constraints imposed by energetic responses to infection may also impair social relationships [22].…”

Calling in sick: impacts of fever on intra-urban human mobility

“…Despite the expected ubiquity of disease impacts on mobility and their documentation in animal systems [11], they have seldom been measured empirically in humans.…”