| Popis: |
Personality and behavioural syndromes are increasingly recognised in many animal species and are now seen as critical to the prediction of non-native species success and impacts. Rainbow trout and brown trout have been introduced globally, but differ in patterns of establishment success and ecological impact. While environmental tolerance may be a driver, thus far the role of behaviour has not been rigorously tested. Here, we investigated whether diploid rainbow trout and diploid and triploid brown trout differ among several key behavioural measures linked to invasibility. We assessed activity, boldness, aggression, and feeding, using open field, novel object, shelter, mirror, feeding, and functional response experiments. We also tested within each fish type for behavioural syndromes comprising correlations among activity, boldness and aggression. Rainbow trout were more active and aggressive but less bold than diploid and triploid brown trout. In small groups, however, rainbow trout were bolder than both types of brown trout. Diploid brown trout were more active and bolder than triploids when tested individually. There was no association between activity and boldness in rainbow trout, but there was in both brown trout. The increased activity and aggression of rainbow trout may reflect an increased stress response to novel situations, with this response reduced in a group. These results suggest that rainbow trout do not manage their energy budgets effectively, and may explain why they are implicated in fewer ecological impacts. Comparative analyses of multiple behaviours of invasive species and genetic variants may thus be key to understanding and predicting invader success and ecological impacts. |
