Avian risk takers stressed

A new study by the University of Exeter has revealed that stressed out birds are more likely to take risks than their relaxed counterparts.

Zebra finch - but is it "bold" or "shy"?

The research team selectively bred zebra finches to create “laid-back”, “normal”, and “stressed” groups of birds. These groups differ by their levels of stress hormone, which in birds is corticosterone.

The research team used a different method to the traditional approach, which is to observe behavioural strategies of birds to separate them into “bold” and “shy”, or “active” and “passive” groups and then assess their physiological differences. In this case, the birds were grouped by their levels of corticosterone production and then behavioural variations were observed. The group found that the stressed birds were the first to take risks when placed in a new environment - they were the first to investigate new feeders and they returned more quickly when startled that their relaxed peers.

Dr Thais Martins of the University of Exeter said: “It initially seems counter-intuitive that birds with higher levels of the stress hormone showed bolder behaviour, normally associated with confidence. However, corticosterone is released to help tackle stress by encouraging the animal to adopt key survival behaviours like seeking food. So on reflection, perhaps it is not surprising that these birds are more likely to explore the environment and look for food.”

The results are published in the journal Hormones and Behaviour.

Leila Sattary