Consistent after all: behavioural repeatability in a long-lived lizard across a 6-year field study

Despite growing attention to the ecological and evolutionary importance of consistent individual differences in behaviour (animal personality), long-term field studies quantifying factors associated with behavioural repeatability remain rare. Here, we studied animal personalities over an 8-year period, representing 6 study years, a wild population long-lived sleepy lizard, Tiliqua rugosa. Using Bayesian generalized linear mixed models for 170 unique individuals total 379 lizard-years, (1) considered effects suite predictors – particularly lizard sex, mass tick counts on aggression boldness (2) assessed (i.e. among individuals), these behaviours different timescales between sexes (3) evaluated correlation, or syndrome, boldness. We found that males were marginally more aggressive bolder than females, had no significant effect loads exhibited positive relationship For repeatability, even long this study, both repeatable across entire data set (∼0.4 ∼0.3, respectively) using all lizards, as well years ∼0.4, lizards observed multiple (93 aggression, 73 boldness). Repeatability did not differ substantially sexes. syndrome despite weak correlation multivariate models, 95% credible interval included zero. Our results are notable because they demonstrate animals may exhibit personality ecologically relevant extended periods face substantial temporal variation social factors, fact has likely consequences.