Good food boosts finches' sex appeal

Male zebra finches prefer well-nourished females

source: Michael Brooke
New Scientist no 2049 September 28 1996 p21

Researchers from Glasgow University have discovered that male zebra finches prefer females that have been fed a protein supplement, to those that have not. The researchers took a captive group of female zebra finches, and split them into two groups, feeding one group on just millet, while the other group received hen's egg supplement as well as millet. The males tended to choose the females which had eaten the supplement. Previous work at the university showed that females given the protein supplement tend to lay larger egg clutches, which are also more viable. It is not known how the males could distinguish between the two groups of females.