THE BIRDS WHO BUNBURY
In Oscar Wilde's play The Importance of Being Earnest, there's a man with a different persona -- even a different name -- in the city and in the country. He's called Ernest in the city, and Jack in the country. He and his friend make up a fictitious invalid buddy with the lovely name of "Bunbury" who lives in the country -- so that they can take trips to "visit" him there, but really so they can behave differently and have a jolly old time. They even have a name for their game! It's called bunburying.
Well this phenomenon of having two personas, one for the country and one for the city, isn't limited to humans. There are birds who bunbury. One of them is the blackbird, as in the picture above. (If you're wondering why it's brown: baby blackbirds are born brown, and they only become black later.) When they are in the city, they eat different things, make houses in different places, and breed at different times of the year. (Maybe even, in bird language, they cheep out different names to each other! But probably not "Jack" and "Ernest".) That's because the city environment is very different from the country. There’s a warmer microclimate compared to adjacent natural habitats. There's artificial light all night long. And there's scraps of human food to eat.
When we think of the country, we think of a natural environment. And when we think of the city, we think of an artificial environment, composed of things made by humans. But maybe this distinction isn't so strict. Cities have lots of animals and plants, and their own ecosystems. And organisms adapt to cities, like the blackbird has.
But for the blackbirds who bunbury, it's not just the behaviour that adapts. What's amazing -- and what scientists from the Max Planck Institute for Ornithology in Andechs/Seewiesen Germany have discovered -- is that their genetics also change. In that sense, they're not really bunburying, like the characters Oscar Wilde's play. It's not just that they are behaving differently. City birds really are different birds than country birds, presumably with a different genetic code. This code tells city birds to breed earlier, and these genetic changes would have evolved in the short time that humans have built cities on the earth.
Dr. Jesko Partecke of the Max Planck Institute, now working at Washington State University in the USA, doesn't bunbury. But he has been studying the differences between city blackbirds and country blackbirds, and he's going to tell you more about their very different ways of life -- and genetic makeup.