Once common species like the cuckoo are at risk of becoming suddenly under threat, if recent declines are anything to go by. Photograph: Erich Kuchling/Rex Features
The news that almost one in eight of the world's bird species are now threatened with extinction may not have come as a surprise. After all, since BirdLife International first published their magnum opus Threatened Birds of the World, back at the turn of the millennium, we have known that almost 1,200 species are at risk.
Now this number has increased to 1,227 species, with 192 classified as "critically endangered", a net rise of two species on last year and up from 182 in 2000. Once a species falls into this category the game is generally up – apart from a few well publicised success stories such as the Mauritius kestrel, once the world population of a species is numbered in dozens or hundreds, rather than thousands, it is usually doomed to a rapid extinction.
One bird added to the critical list has only just been discovered. The gorgeted puffleg joins the world's 350 or so species of hummingbirds, at least temporarily, before its Colombian montane habitat is destroyed so celebrities can sniff cocaine up their noses.
Other species are hanging on by such a slender threat that they are, to all intents and purposes, extinct. The list contains birds such as Bachman's warbler, ivory-billed woodpecker and Eskimo curlew, despite the fact that none of these North American species has been seen alive for many years. Things aren't much better on this side of the Atlantic: the slender-billed curlew hasn't been reliably sighted for a decade now, and appears to have gone the way of the great auk and dodo.