Roger Ratcliffe on the
bittersweet notes of early birdsong

Can we hear climate change? Does it actually make a noise? Well, of course the answer is yes. It’s that machine gun rat-tat-tatting on the roof when rain beats down with more terrifying velocity than you can ever remember. It’s the howls  of those storms that are given such friendly, unthreatening names by the  Met Office. And if you’re unfortunate enough to be there, it’s the roar of torrential floods as they engulf everything in their path.

Last week I discovered a new sound of climate change. This one was decidedly pleasant, though, and for a little while I enjoyed listening to it fill the air in my back garden. I’d heard it many times before, and it wasn’t until I thought “hang on, this is just the third week of March” that I made the connection with global warming.

Being the first hot spell of the year, my back door was wide open. A male robin was tunefully declaring to other robins that this was his territory. A blackbird was also in full song on a neighbour’s gable end. Then from deep within a bush I heard something that should not have been part of this early spring concerto.

It was a lilting trill of descending notes, as if a bird was practising running down the scale. Although  a recreational birdwatcher, I confess I’m not really hot when it comes to identifying bird song, but this one was easy to nail. I was listening to a fairly common summer visitor, the willow warbler.

It’s a small and fairly bland bird, and being virtually indistinguishable from its close cousin the chiffchaff their totally different songs are key to telling them apart and, therefore, familiar to most people with a smattering of bird knowledge.

According to my bird identification book, willow warblers begin to arrive from southern Africa in the second week of April and are still migrating here in early June. That one was now in full voice in my garden, according to a  new report by the US National Academy of Sciences, is yet another sign of  climate change.

While it may seem a positive thing to have such a pleasant songster appearing earlier in the season, it isn’t good for the willow warbler according to the study.  By advancing their breeding season here by three or four weeks they are finding that the small insects they depend on to feed their young are not as abundant as they are in late spring and summer. This is leading to the birds decreasing in size, and almost a third of them reducing their number of offspring.

It’s a trend that is also affecting other species. The British Trust for Ornithology believes that climate change has reduced the population of our most common birds by around ten per cent. Personally,  I get little encouragement from the fact that at least some species, such as the white heron-like little egret, have shifted northwards in the last  20 years.

All this is happening under the radar of media coverage about the need to reduce carbon emissions. But listening to the willow warbler in my garden reminded me that with all that is happening in Europe right now, COP-26 in Glasgow last November seems like a geological age ago. The warnings issued then are in danger of being forgotten.

Roger Ratcliffe has worked as an investigative journalist with the Sunday Times Insight team and is the author of guidebooks to Leeds and Bradford. Follow him on Twitter @Ratcliffe