The response to the social environment reveals sex-dependent behavioural syndromes in the Bosca's newt (Lissotriton boscai)

There is growing evidence of correlated behaviours across time, situations and/or contexts (behavioural syndromes) in animals, and their link with fitness makes these studies mandatory to understanding the species' behavioural and evolutionary ecology. Whereas the role of the social environment on behavioural syndromes is receiving increasing attention, experimental studies testing whether environmental fluctuations govern sex-dependent behavioural syndromes are scarce. I performed an experiment to test for the existence of sex differences in activity syndromes through a changing social environment. Males and females of Bosca's newt (Lissotriton boscai) were faced with three social situations perceived through chemical cues (own odour, no odour and same-sex conspecific odours) to measure their activity levels. Comparisons of the activity levels showed that both males and females discriminated the odourless stimuli from newt odour (either their own or the conspecific stimuli). Whereas activity levels were positively correlated between their own and the odourless stimuli in both sexes, the association between the odourless and conspecific stimuli was positive in males but decoupled in females. This is the first experimental evidence of sex differences in activity syndromes of wild-caught animals in response to social changes.