The relationship between individual behavioural styles, dominance rank and cortisol levels of cats living in urban social groups

Individual animals show differences in temperament, often correlated with ecologically important behavioural patterns such as dominance, and with physiological responses to environmental perturbations, such as cortisol levels. Identifying these temperaments in animals may reveal adaptive patterns of behaviour and physiology that could be used to improve their fitness and welfare in human-controlled environments. We examined the possible relationship between individual temperaments, social dominance levels and cortisol levels in regularly fed urban groups of free-roaming domestic cats (Felis catus L.) that are routinely subjected to the Trap-Neuter-Release procedure (TNR). We designed three behavioural tests that aimed at assessing the cats' boldness levels and determining the individual temperaments using a principle component analysis. Individual social dominance rank was determined from observations of social encounters before and during feeding. Cortisol levels were measured from hair samples collected from the cats. Significant differences were exclusive to females, with the intact females scoring higher on the boldness factor compared to the neutered females (median of 0.47 ± 0.981 and -0.168 ± 1.015, respectively, Post hoc Chi square, P < 0.05). A positive correlation was found between cortisol levels and dominance scores in the intact females: the more dominant an individual intact female was the higher her cortisol level was (n = 14, Pearson correlation, R² = 0.592, P < 0.05). No correlation was found between dominance rank and boldness or between boldness and food dominance. In summary, our results suggest that in urban cat feeding groups, where cats are dependent on a regular food source and where their individual survival does not absolutely depend on their dominance rank, their social status was independent from their individual boldness. The differences found in the behavioural tests, between the neutered and the intact females are probably rooted in different motivation levels rather than different temperaments.