Personality is correlated with natal dispersal in North American red squirrels (Tamiasciurus hudsonicus)

Abstract

Individual natal dispersal behaviour is often difficult to predict as it can be influenced by multiple extrinsic and intrinsic factors. Individual differences in personality have been shown to be an important correlate of dispersal behaviour. However, the relationships between personality traits and dispersal are often inconsistent within and across studies and the causes of these discrepancies are often unknown. Here we sought to determine how individual differences in activity and aggression, as measured in an open-field trial, were related to natal dispersal distance in a wild population of North American red squirrels (Tamiasciurus hudsonicus). For 14 cohorts, while individual aggression consistently had no association with dispersal distance, the association between activity and dispersal fluctuated through time, mediated by population density. The environmental-dependence of the relationship between personality and dispersal in this population is indicative of the importance of considering external conditions when predicting dispersal behaviour.

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

“…Studies on the great tit also found a relationship between dispersal distance and behaviour in novel environment, specifically immigrants and birds dispersing farther explored the novel environment faster (Dingemanse et al, ; Quinn, Cole, Patrick, & Sheldon, ), and this link was also found at the genetic level (Korsten et al, ). Similar relationship was also reported in fish and in mammals (Cooper et al, ; Rasmussen & Belk, ). It is difficult to compare these results with ours, because there are remarkable differences in the underlying study designs and the ecology of the focal species, which should also be considered.…”

The new kid on the block: immigrant males win big whereas females pay fitness cost after dispersal

“…Pockets of suitable habitat (white spruce density > 1000 trees per hectare) were, on average, 464.78 ± 241.44 m away (Yukon Vegetation Inventory ). These distances are greater than the dispersal distances of local recruits that move an average of only two territory widths from their natal site (96.00 m ± 94.00 SD, Berteaux & Boutin ; 102.00 m ± 107.00 SD, Cooper et al ). We also tested for edge effects by designating a ‘core’ area in the centre of each population and comparing individuals living in the core with those living outside this area (but still in the population), thereby restricting our analysis to only individuals born in our populations.…”

“…While male‐biased dispersal is documented in many mammalian species (Greenwood ; Dobson ), in red squirrels, both sexes disperse similar distances (Berteaux & Boutin ; Cooper et al ). Despite these previous studies documenting a lack of sex‐difference in dispersal distances when looking at successful within‐population movement, we documented a clear sex‐bias towards female residency and male immigration, and sex‐dependent fitness differences after recruitment when accounting for immigration.…”

“…Juveniles experience high mortality (40-60%) between birth and weaning (Boutin & Larsen 1993). Most red squirrels exhibit a degree of philopatry (Larsen & Boutin 1994;Haughland & Larsen 2004), recruiting an average of two territory widths from their natal site (Berteaux & Boutin 2000;Cooper et al 2017). Breeding dispersal (i.e.…”

“…As assessed by successful local recruitment (i.e. only includes individuals that survive their first winter and acquire and defend a territory with a midden in our populations), females and males have similar dispersal distances (Berteaux & Boutin 2000;Cooper et al 2017), although females tend to recruit slightly closer to their natal site than do males (Berteaux & Boutin 2000) and are more likely to have a natal site bequeathed to them (Berteaux & Boutin 2000;Lane et al 2015). Juveniles that recruit on their natal site have higher winter survival than juveniles that recruited elsewhere in their first winter (75 versus 58%, respectively; Berteaux & Boutin 2000).…”