© DIck Daniels / WikimediaRose-ringed Parakeet (Psittacula krameri) at Birds of Eden aviary, South Africa.
Stanwell, England - The evening started peacefully enough at Long Lane Recreation Park in the western suburbs of London. But just before sunset, five bright green missiles streaked through the air toward a row of poplars at the park's edge.
Within minutes, hundreds more of the squawking birds - in formations 10, 20, 30 strong - had passed above the tidy homes and a cricket club, whizzing toward their nightly roost.
Native to the Indian subcontinent and sub-Saharan Africa, the rose-ringed parakeet is enjoying a population explosion in many London suburbs, turning a once-exotic bird into a notorious pest that awakens children, monopolizes garden bird feeders and might even threaten British crops.
One rough estimate put the population in Britain at 30,000 a few years ago, up from only 1,500 in 1995. Researchers at Imperial College London are now trying a more scientific census through its Project Parakeet, which enlisted volunteer birders around the country for simultaneous counts on a recent Sunday evening.