The findings, published today in Science magazine, showed that males with bright beaks had stronger immune systems than plainer finches, which meant picky females were far more likely to get a healthier mate as well as a better-looking one.

They found male zebra finches that ate more carotenoids developed redder beaks and became more attractive. They also enhanced their immune systems. Dr [Jonathan Blount] said the findings provided a lesson for all males looking for a girl.

WHAT'S UP: Bugs Bunny swore by his favourite tea-time treat; FOR THE BIRDS: Dr Blount used finches to test out his theory that carrots attract the opposite sex