Linbro Park and escaped birds: how they can breed

We have been in Linbro Park for five years. In this time we have noticed an enhanced incidence of parakeets, attracted by our pecan nut tree. We love having them here, but each year their number grows. Look at what will happen, based on what has happened in London:

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.

“I was delighted when I first saw one in my yard, but when you have a flock of 300, it’s a different matter,” said Dick Hayden, a retiree who was volunteering at Long Lane Park. “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.” 

http://www.nytimes.com/2011/05/14/science/earth/14parakeet.html?_r=2&nl=todaysheadlines&emc=tha3