Some birds have it all. Male siskins with brighter, more attractive plumage are better at finding food than their less eye-catching counterparts.

Fernando Mateos-Gonzalez and his team at the Natural History Museum of Barcelona, Spain, measured the length of a yellow stripe on the wings of male siskins (Carduelis spinus; pictured). Females are known to pick mates on the basis of the length of this stripe. The researchers challenged hungry males to unlock a cache of pine seeds blocked by toothpicks.

Credit: A. PARKINSON/NATUREPL.COM

Birds with longer yellow stripes solved the problem more quickly than those with shorter stripes. The authors ruled out age, size and social dominance as possible contributory factors, and conclude that fancier feathers might help discerning females to select mates that are not only sexier, but also smarter.

Biol. Lett. doi:10.1098/rsbl.2011.0163 (2011)