Habitat-dependent effects of personality on survival and reproduction in red squirrels

Abstract

Variation in intrinsic (body mass, reproductive condition) and extrinsic factors (habitat quality, spatiotemporal variation in food availability) can affect the costs and benefits of personality traits. Relationships between personality and fitness components can vary with changes in population density and/or habitat quality. Here, using capture-mark-recapture data of individually marked Eurasian red squirrels (Sciurus vulgaris), we explored whether indices of boldness and exploration are correlated with local survival in either of the sexes and with a measure of reproductive success in females, under different conditions of food availability. PCA scores derived from the number of captures (trappability) and number of different traps where an individual was captured (trap diversity), in the first one or two years of presence, were used as indices of personality (boldness and pure exploration). The relationships between boldness and local survival differed between habitats in both sexes. Bold squirrels survived better than shy ones in Norway spruce forest, while in the other two study areas (Scots pine, or mixed spruce-fir forest) survival was lower for bolder squirrels. Pure exploration behavior was negatively correlated with local survival in all habitats and in both sexes. Female reproductive success increased with body mass and decreased with the tendency to explore, a relationship consistent across habitat types. Bolder females did not have a reproductive advantage in years of poor food availability. We suggest that costs and benefits of boldness vary with spatio-temporal differences in availability of high-quality food resources which may help to maintain variation in personality in red squirrels in heterogeneous landscapes.

Reactive stress-coping styles show more variable reproductive expenditure and fitness outcomes

“…For example, the differential success of fast and slow exploring great tits (Parus major) across breeding seasons depending upon habitat resource quality 10 . A similar pattern of changing costs and benefits of boldness dependent upon spatio-temporal changes in resources was also found in Eurasian red squirrels (Sciurus vulgaris 42 ). Such processes represent potential solutions to the conundrum of the maintenance of inter-individual variation in natural populations through differential costs and benefits dependent upon either spatial or temporal variation in environment 4 .…”

Individual differences in behaviour explain variation in survival: a meta-analysis

“…Parus major major wild (Quinn et al 2009) Parus major major wild (Kain & McCoy 2016) Physella acuta lab (Hulthén et al 2017) Rutilus rutilus caspicus wild (Santicchia et al 2018) Sciurus vulgaris orientis wild (Morales et al 2013) Sitophilus zeamais lab 20 (Shackleton et al 2005) Teleogryllus commodus lab (Monceau et al 2017) Tenebrio molitor lab (Boulton et al 2018) Xiphophorus Table 3. Heterogeneity estimates (I ) with the associated standard deviation (in brackets) for the global meta-analytic model.…”

Measuring personality traits in Eurasian red squirrels: A critical comparison of different methods

“…Studies in natural populations based on capture–mark–recapture of animals can rely on the sampling method itself to obtain measure of individual behaviour and/or personality. Indeed, individual differences in willingness to enter a baited trap (trappability) can be considered as a measure of an animal's propensity for risk‐taking (Bisi et al., 2011; Boon et al., 2008; Boyer et al., 2010; Le Coeur et al., 2015; Montiglio et al., 2012; Réale et al., 2000; Santicchia, Gagnaison, et al., 2018; Santicchia et al., 2019). Reactions to risky situations, excluding any component of novelty which is exclusively related to exploration propensity (Réale et al., 2007), have been identified in literature as a measure of individual boldness (Réale et al., 2007).…”