Male European starlings—small, greenish-black birds with a hint of iridescence—may not be much to look at. But they do like to add a little flourish to their nests: fresh herbs. Originally considered a strategy for attracting a mate, the use of aromatics in nest building is now thought to have an additional role in keeping baby starlings healthy.
“People have proposed that the birds add the herbs to their nests because they improve the fitness of their offspring,” says Juan Vicente Gallego Rubalcaba, a biologist at Rey Juan Carlos University in Madrid who studies the adaptive strategies of birds. Indeed, studies have shown that starlings raised in herbed dwellings tend to fare better—having fewer parasites and weighing more—than youngsters brought up in nonherbed nests.
What researchers haven’t been able to pinpoint is how exactly the herbs exert an influence over baby birds’ health. To answer this question, Helga Gwinner of ...
