Sex-specific but not urbanisation-related behavioural differences in a wolf spider, Pardosa alacris

Urbanisation, one of the main driving forces of the decline in arthropod diversity, is a global environmental problem. Urbanisation causes changes to the size, connectivity, structure, and environmental parameters of their natural habitat. Due to a host of novel conditions and situations, high exploratory and risk-taking behaviours are beneficial traits to cope with urban environments. Therefore, we hypothesised that urban spiders should display more exploratory and risk-taking behaviour than their rural conspecifics. We tested 253 individuals of a widespread, forest-associated ground-dwelling wolf spider species, Pardosa alacris, sampled from rural and urban forest sites during their peak activity period, for their locomotory activity, exploratory and risk-taking behaviour by six frequently used behavioural measures. Combining the studied behavioural measures into composite scores using redundancy analysis, we identified two composite variables, the activity-exploration-boldness and the risk-taking behavioural ones. Behaviour measured by the composite activity-exploration-boldness score was significantly repeatable, but not the composite risk-taking behavioural one. There were no urbanisation-related differences in the composite behavioural scores, suggesting that higher exploratory or risk-taking behaviour may not yield fitness benefits in this generalist predator. We found, however, significant sex-specific differences in the composite activity-exploration-boldness behavioural scores. The higher activity, exploratory and boldness in males than females may be explained by their different life-history strategies and sex-specific selective pressures.