Animal personality is now frequently reported in wild and captive populations. It has been shown to be moderately heritable and to have potentially important fitness consequences. Variation in personality within a population may be maintained by balancing selection if different values of personality traits are favoured under different conditions. We measured personality in 98 female North American red squirrels (Tamiasciurus hudsonicus Erxleben), and examined whether its variation could be maintained by changing selection pressures acting via reproductive traits and yearly variation in food abundance. There was no effect of personality on parturition date or litter size, but a female's activity was correlated to the growth rate of her offspring in the nest, and her aggressiveness was correlated to their survival in the nest and overwinter. The magnitude and direction of the effects changed among life history stages and years, possibly in association with food supply in some cases, and may indicate a role for balancing selection in the maintenance of personality.

Dépt des Sciences Biologiques, Univ. du Québec à Montréal, CPÁ8888, succursale centre-ville, Montréal, QC, H3C 3P8, Canada.Personality affects many aspects of an individual's behaviour, life history and fitness, and has been shown to be moderately heritable in wild populations. Correlations between personality and risk-taking that lead to life history tradeoffs could act to maintain variation in personality within a population, but this has not yet been tested. In this study, we used females from a marked population of North American red squirrels in Kluane, Yukon, to determine whether personality predicts risk-taking in the wild, and whether these risk-taking behaviours result in life history tradeoffs. We measured personality in open field and mirror image stimulation tests and extracted two traits, activity and aggressiveness, using principal component analysis and mixed model techniques. Using trapping records for individuals from February to September 2005, we obtained three measures of risk-taking: the number of trapping events, the number of different trapping locations, and the maximum distance between the home territory and a trapping event. We used GLMs to determine whether the activity and aggressiveness of individuals are related to these risk-taking behaviours, and found that active squirrels were trapped significantly more frequently and at a greater number of locations. There was also a significant interaction between activity and aggressiveness to affect the maximum capture distance. To determine if there are fitness tradeoffs associated with these risk-taking behaviours, we examined female bequeathal behaviour and survival. Bequeathing a territory increases offspring probability of overwinter survival, and we found that an increasing number of trapping locations was associated with an increasing tendency to bequeath. Active females were less likely to survive until the following spring. Risk-taking is therefore predicted by personality in this population, and they affect both survival and territorial bequeathal. These fitness tradeoffs may therefore lead to the maintenance of variation in personality.

Consistent individual differences in behaviour, and behavioural correlations within and across contexts, are referred to as animal personalities. These patterns of variation have been identified in many animal taxa and are likely to have important ecological and evolutionary consequences. Despite their importance, genetic and environmental sources of variation in personalities have rarely been characterized in wild populations. We used a Bayesian animal model approach to estimate genetic parameters for aggression, activity and docility in North American red squirrels (Tamiasciurus hudsonicus). We found support for low heritabilities (0.08–0.12), and cohort effects (0.07–0.09), as well as low to moderate maternal effects (0.07–0.15) and permanent environmental effects (0.08–0.16). Finally, we found evidence of a substantial positive genetic correlation (0.68) and maternal effects correlation (0.58) between activity and aggression providing evidence of genetically based behavioural correlations in red squirrels. These results provide evidence for the presence of heritable variation in red squirrel behaviour, but also emphasize the role of other sources of variation, including maternal effects, in shaping patterns of variation and covariation in behavioural traits.

Ophidian serpentoviruses, initially referred to as nidoviruses, were first documented in captive pythons nearly ten years ago. Since then, much has been learned about these important pathogens, now classified in subfamily Serpentovirinae of family Tobaniviridae and representing an important emerging pathogen that threatens captive snakes. Serpentoviral infections are best characterized in pythons (family Pythonidae), but have also been documented in boas (family Boidae) and colubrids (family Colubridae), as well as shingleback skinks (Tiliqua rugosa), veiled chameleons (Chamaeleo calyptratus), and the Bellinger River snapping turtle (Myuchelys georgesi). Clinical signs include increased oral mucous secretion, oral mucosal reddening, dyspnea, anorexia, and weight loss. Subclinical infections can also occur, and multiple studies report a lack of correlation between clinical signs and presence of serpentoviral nucleic acids in snakes. Lesions associated with serpentoviral infections predominantly occur in the upper respiratory and gastrointestinal tracts but can also extend to the lungs. Microscopically, these lesions may consist of inflammation, epithelial proliferation, and proliferative interstitial pneumonias, which can be complicated by concurrent bacterial bronchopneumonia. The most common method of diagnosis is reverse transcription PCR to detect viral RNA, and oral/choanal swabs are reliable samples for ante- or postmortem diagnosis. Specific treatment protocols have not yet been described, and management is based on supportive care. This manuscript presents a narrative review of all serpentovirus publications to date with perspective from researchers working to further characterize these pathogens, with the goal of serving as a comprehensive clinical and diagnostic overview for clinicians, zoological curatorial staff, wildlife biologists, and hobbyists.