Leading article: New arrivals

Ever seen a yelkouan shearwater out by the seaside, or a citril finch on the garden birdtable? Almost certainly not. But you may do in future, for these are just a few of the new birds on our block. Spotted for the first time in Britain in 2008, their presence has now been verified by the British Rare Birds Committee.

Oddly, given the doom-mongering about species decline, it appears that more species of bird are present in Britain today than were present a century ago. Thus the list for 2008 – the latest – is likely to be the longest ever, at 418.

This is partly a result of more efficient bird watching; there are more twitchers around, and they now have long-lens cameras too. But it is also a result of global warming, which means more birds that naturally belong in the Mediterranean or the Alps turn up and feel, if only briefly, "at home" in Britain. Climate change, it seems, so worrying for us humans, is only adding to the rich variety of our wildlife.