The parakeet population in Britain has exploded in recent years, up from 1,500 in 1995 to 30,000 a few years ago. The result? Scenes that could be straight out of Alfred Hitchcock's The Birds, like one recent evening at a suburban park that saw hundreds of parakeets whizzing by in formations of 10, 20, or even 30. “I was delighted when I first saw one in my yard, but when you have a flock of 300, it’s a different matter,” a local tells the New York Times. “They eat all the berries. They ate all the food from my feeder in one day; it was ludicrous. I had to stop putting it out because it got too expensive."
No one knows exactly why parakeets, native to India and Africa, are procreating so wildly in London—where the one-time exotic pets have turned into pests. It could be that as gardeners plant more exotic plants, the birds are provided with more food, or maybe suburbanites are simply putting out more bird feeders. A warmer climate over the past few years has also likely helped. Officials are watching the birds closely, as they could easily threaten crops, but so far they seem to enjoy the cities and suburbs more than the agricultural areas.