OLL LEWIS: Hope Springs Eternal

About a week and a half ago Jon published a blog I had written about the birds we have had visiting our garden this winter. Among the list of birds was a pair of turtle doves (Streptopelia turtur). This was of particular interest because they should not be here at this time of year (mid-February) as they usually winter in Africa, returning to Europe in spring with the warmer weather.

It was suggested that this may have been a misidentification of a collared dove, which to be honest, were I a twitcher rather than just a keen amateur bird-watcher, might have been the first explanation to my mind as well. However, the pair of doves in question were almost certainly turtle doves and this was confirmed by the appearance of a collared dove in the garden over the past few days, which looks quite different. The turtle doves have a more peach-like tinge to their plumage than the pale grey tinge of the collared dove; the markings of the turtle dove's wings are more ‘busy’ than the collared dove; and the turtle doves are smaller than the collared dove.

I hope to get some photographs or footage of the turtle doves to show you all but for now you’ll have to be satisfied with the fact that I’m a good 95% sure of my identification and that we have a pair of turtle doves visiting the garden that should be somewhere a lot warmer at this time of year.

Whether those doves have migrated back to Britain over a month early or whether they didn’t migrate in the first place I have no idea as the last time I saw them before we put the feeders out was some time around the start of autumn. Despite what the cold weather would have us believe, spring is full flow in North Devon having started, as far as the plants and animals are concerned, almost along with the start of February this year. The snowdrops in our garden, which usually start to flower around the 10th of February, started flowering towards the end of January and our chicken started to lay eggs last week when she usually starts laying at the beginning of April.

Although early springs are often blamed on global climate change by the press the truth is often far more complicated. While climate change plays a part there are a multitude of other factors that can come into play. Some of these factors can be part of the evolutionary ‘arms race’ between plants, herbivores and predators; early emergence can in some cases prove to be a selective advantage meaning there is a greater chance of passing on genes to the next generation before you get eaten. Over several generations plants can start emerging earlier, which has a knock-on effect on the things that eat them emerging earlier and so on up the food chain. A recent extensive study into the timings of the start of spring found that on average, spring starts 11 days earlier than it did 30 years ago (http://news.bbc.co.uk/1/hi/sci/tech/8506363.stm).

Eventually this trend should self-regulate as plants and animals will reach the cut-off point when early emergence’s advantages are out-weighed by the disadvantages cold weather can bring so I would doubt we’d ever see snowdrops and summer birds at Christmas, but for now I’ll be keeping an eye on the local wildlife to see if anything else turns up early.