BY DAUBING budgies with sunscreen, researchers have shown that the birds
fluoresce to increase their sexual attractiveness.
Justin Marshall of the University of Queensland in Brisbane and his
colleagues used UV-block to stop any fluorescence from the birds’ yellow crown
and cheek feathers without changing their colour, while control birds were
smeared with petroleum jelly, which doesn’t block UV light. Both male and female
budgies preferred mates that kept their fluorescent glow (Science, vol
295, p 92). Numerous animals have fluorescent pigments, but this is the first
demonstration that they can be used in sexual signalling.
