What's Brought 32,000 Parakeets to London's Suburbs?

In 1995, it was estimated that 1,500 of the birds made their home in Britain. Today, the estimate is 32,000 in southeast Britain alone, mostly around the capital. It is generally agreed that the species was first brought to Europe as pets, reports the New York Times. But the reasons for the population explosion are a lot harder to pin down. Theories include a warmer climate that is closer to the birds' native regions, the removal of predators, and more obliging suburbanites putting out bird feed.