Embargoed 7.00 p.m. Thursday 3 January 2002

Humans often use fluorescence to attract attention, but now a team of scientists from the University of Glasgow, Imperial College London and the University of Queensland have demonstrated that parrots also use their fluorescence to attract attention, from sexual mates. Their findings are published today 4 January 2002 in the journal Science.

Dr Kathryn Arnold of the Institute of Biomedical & Life Sciences at the University of Glasgow says: "Humans use fluorescence in advertising, for example, because it is so eye-catching, but we didn't know whether natural fluorescence in the parrot family was similarly involved in communication or merely a by-product of pigmentation. We have been able to show that both male and female birds in the parrot family use their 'glowing' plumage to attract sexual mates."

Fluorescence appears to glow because it absorbs ultra-violet (UV) light, which humans cannot see, and re-emits it as human-visible yellow light. The researchers worked with wild-type budgerigars in Australia and during the experiments masked fluorescent plumage using basic sunblock cream, which absorbs UV-light. A control group was treated with pure vaseline. The research ruled out other possible uses of the fluorescent colours such as species identification or social grouping.

Dr Arnold and her colleagues studying budgerigars in Australia demonstrated that the fluorescent pigment makes the head feathers appear much brighter to other budgies. "The colour vision of birds is much better than human vision," she explains. "To us, all yellow feathers might look the same but budgerigars can detect much finer differences in the qualities of colours."

It has been known for sometime that the quality of the colour of a bird's plumage is a reflection of the health and vitality of the bird. High quality plumage is therefore taken to indicate a more desirable mate with the prospect of healthier and sexier offspring.

The research was funded by the Australian Research Council and conducted by Dr Arnold of the University of Glasgow, Dr Ian Owens of Imperial College London and Dr Justin Marshall of the University of Queensland.

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For further information contact the University of Glasgow Press Office on 0141 330 3535
or Dr Kathryn Arnold, 0141 330 2898, Email: k.arnold@bio.gla.ac.uk

First published: 3 January 2002