Blackbirds Evolving Uptown:

More than a century ago, some European Blackbirds gave up the commuting life. The traditional routine was to nest in northern forests but head for southern Europe or northern Africa at the first sign of winter. Then some populations discovered that winter in the city isn't half-bad: The microclimate is warm with plenty of tasty leftovers. So strong is the appeal of city life, according to a research team in Germany, that it is has not only changed the blackbirds' behavior, but their genetics, too.