Washington, Nov 30 (ANI): It is well known that animals have personalities, but it may come as a surprise to many to learn that birds also do.
For instance, individual birds vary in their levels of curiosity, with distinctions being made between 'fast' and 'slow' explorers.
A considerable body of research has examined the differences between fast and slow birds but the levels of stress hormones (glucocorticoids) have not previously been investigated, although these hormones are known to be important in a number of aspects of bird behaviour.
Mareike Stowe at the University of Veterinary Medicine, Vienna has now shown significant differences in the levels of glucocorticoids in fast and slow birds.
She also found that fast birds respond to stress by dramatically increasing their glucocorticoid levels, while slow birds exhibit a much moderate response.
The Great Tit is a common garden bird of many countries in Europe and Asia. Great Tits are generally thought of as fairly inquisitive but it has long been known individuals vary considerably in their willingness to explore new surroundings.
Some birds - known as "fast" or "proactive" - are quick explorers and are comparatively aggressive, whereas "slow" or "reactive" birds are more cautious.
The differences are at least in part genetically determined and as a result scientists in Holland, with whom the Vienna group has been collaborating closely, have been able to use this behavioural trait as a basis for selecting lines over several generations.
The results are published in the XXX issue of the journal Hormones and Behavior. (ANI)