Bye-Bye Birdie

Everyone knows that birds migrate, but until now, it's been unclear how they know where to go and when to leave, says New Scientist's Janelle Weaver. Researchers at the Max Planck Institute for Ornithology recently set out to find out the "how" of bird migration — their results are published in the Proceedings of the Royal Society B. They trapped birds from 14 populations of the European blackcap — they do their migrating at night — and took blood samples to see whether they could find genetic markers to explain the birds' nocturnal behaviors, Weaver says. And they found one — gene ADCYAP1. The longer the allele, they found, the more restless the bird became at night. "The gene may do more than simply encourage night-time fidgeting: it encodes a protein called PACAP, which plays a major role in melatonin secretion, energy metabolism and feeding," Weaver says. "These functions are crucial for preparing birds for long flights."