Does exploratory behavior or activity in a wild mouse explain susceptibility to virus infection?

Abstract

Exploration and activity are often described as trade-offs between the fitness benefits of gathering information and resources, and the potential costs of increasing exposure to predators and parasites. More exploratory individuals are predicted to have higher rates of parasitism, but this relationship has rarely been examined for virus infections in wild populations. Here, we used the multimammate mouse Mastomys natalensis to investigate the relationship between exploration, activity, and infection with Morogoro virus (MORV). We characterized individual exploratory behavior (open field and novel object tests) and activity (trap diversity), and quantified the relationship between these traits and infection status using linear regression. We found that M. natalensis expresses consistent individual differences, or personality types, in exploratory behavior (repeatability of 0.30, 95% CI: 0.21–0.36). In addition, we found a significant contrasting effect of age on exploration and activity where juveniles display higher exploration levels than adults, but lower field-activity. There was however no statistical evidence for a behavioral syndrome between these 2 traits. Contrary to our expectations, we found no correlation between MORV infection status and exploratory behavior or activity, which suggests that these behaviors may not increase exposure probability to MORV infection. This would further imply that variation in viral infection between individuals is not affected by between-individual variation in exploration and activity.

Relationship between population density and viral infection: A role for personality?

“…Second, we have found evidence for the existence of consistent differences in exploration, (i.e., animal personality) in this species (Vanden Broecke et al, ). Nevertheless, while it has been hypothesized that personality may affect virus infection probability (Barber & Dingemanse, ; Kortet, Hedrick, & Vainikka, ), we found no behavioral differences among individuals with or without MORVab (Vanden Broecke et al, ; Figure (3&4)).…”

“…Activity was measured by dividing the floor of the box into 12 squares and counting the number of times an individual changed squares during 10 min (Vanden Broecke et al, ). This was quantified using MTrackJ (Meijering, Dzyubachyk, & Smal, ), a plugin for ImageJ (Schneider, Rasband, & Eliceiri, ).…”

“…We therefore ran two LMM with the two principal components as response variables. In each model, we included reproductive age (adult or juvenile), sex (male or female), and sequence of recordings (binomial variable describing if it is the first time an individual had been recorded or subsequent recordings) to control for habituation to the test (Vanden Broecke et al, ). Serological data were included in the model by dividing the individuals into four groups to avoid collinearity: individuals that were (a) MORVab negative ( N = 93) or (b) MORVab positive ( N = 54) during the whole experimental setup.…”

“…Third, our experimental setup allowed us to disentangle the relationship between density and personality at both the between‐ and within‐individual level (Figure (1)). On the between‐individual level, we expect to catch more explorative individuals with increasing density, due to the influx of juveniles into the population (Leirs, Verhagen, & Verheyen, , ) as juveniles are more explorative than adults (Vanden Broecke et al, ). On the within‐individual level, we expect plasticity with changing density, since social interactions in M. natalensis have been shown to change plastically with density (Borremans et al, ).…”

A behavioural trait displayed in an artificial novel environment correlates with dispersal in a wild bird

“…Accordingly, a positive relationship was found between behaviour in a novel environment and activity in a familiar environment (David, Auclair, & Cézilly, ; Siwak, Murphey, Muggenburg, & Milgram, ), as well as the former and risk‐taking behaviour (David et al, ; van Oers, Drent, Goede, & Noordwijk, ), indicating that behaviour in novel environment is connected to activity and risk‐taking behaviour in other contexts. However, not every study found such relationships (Nyqvist, Gozlan, Cucherousset, & Britton, ; Ruuskanen & Laaksonen, ; Vanden Broecke et al, ). Behaviour in novel environment is apparently also related to the stress response, as slow exploring birds generally had higher stress responses (Baugh et al, ; Bousquet, Petit, Arrivé, Robin, & Sueur, ; Carere, Groothuis, Mostl, Daan, & Koolhaas, ), but an opposite relationship was found in rodents (Crino, Larkin, & Phelps, ).…”