A new University of Glasgow study has found that birds in poor condition put more anabolic steroids in their eggs than those in better health. Researchers say the findings could be compared to the use of steroids in the sports world where top performers don't need to resort to steroids to conceal poor performance.

"We originally thought that gulls in good condition would put more steroids in their eggs. Steroids accelerate embryo growth, help a chick fight its way out of the shell and make it beg more vigorously for food. But we discovered that healthy birds don't tend to give their eggs this extra boost", said project researcher, Dr Nanette Verboven.

Researchers also found that while anabolic steroids, such as testosterone, is thought to assist a chick's development, steroids didn't necessarily effect growth or the chances of survival after birth.

The study monitored a colony of healthy lesser black-backed gulls and compared their eggs with those laid by gulls in poorer condition in a control group. The research was conducted on Walney Island off the coast of Cumbria.

Further research is planned into how the female bird's condition effects their eggs.

Media Relations Office (media@gla.ac.uk)

For further information on this study please contact Nanette Verboven Tel: 0141 330 4954, Ruedi Nager Tel: 0141 330 5976 or Pat Monaghan Tel: 0141 330 5968.

To contact the press office please call Judith or Kate on Tel: 0141 330 3535.

First published: 22 October 2003