No one knows exactly why population exploded
                                
                                
                                    (Newser) -
                                    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...