Blackbird singing in the dead of night...

Birdsong at night is a haunting sound, at once beautiful and cheering, and faintly disturbing, wrong. Round my way, the birds seem more and more to be singing in the dead of night. This last week or so it's been going on at all hours, from long after dark to long before dawn - has anyone else noticed a surge? By the sound of it, it's mostly robins, with the odd blackbird and the occasional wakeful sparrow. Why are they doing this? The latest thinking, based on some interesting research published in 2007, is that the birds (robins at least) are singing at night because it's too noisy during the day for them to make themselves heard. Anyone who's been near a robin in full belligerent song might find this hard to believe, but the research looks pretty solid, and noise seems a far more important factor than light pollution. Traffic noise in particular is no doubt on the increase in my area, as everywhere else - it's certainly enough on some local roads to make conversation at normal volume difficult - but lighting levels too seem to be rising all the time, and surely the spreading of a kind of artificial day into the the nighttime must be having some effect on the birds' metabolism and habits. Certainly it would be no bad thing - from every point of view - if there was less traffic on the roads and more lights were dimmed, or simply removed. There are odd reports of cash-strapped councils cutting back on street lighting, and this might help - but little prospect of any slowing in the relentless growth of motor traffic. Nocturnal birdsong - once so seldom heard that hearers would assume (nearly always wrongly) it was the nightingale - is likely to become an established feature of the urban soundscape. One can only hope all these sleepless night aren't turning the birds into groggy irritable wrecks and ruining their days.