Happy Sunday! Been there, done that, brought the Tee-Shirt! All I had for my efforts were a Swallow (my first locally since June 16th) three Reed Warbler and an overflying Cormorant. No sign of any Swift so far today (sign of the times?) and Ray Fellows got in touch yesterday to confirm successful breeding by the Great Crested Grebe but that’s about it for the bird front (more life in a Tramps Vest as they say!).
So what is it that has got me perplexed?
You may recall that last Sunday I found my first Small Skipper butterfly of the year? Well today, in the usual area there were about seven or eight 'small-type' skipper Butterflies at least three of which were definitely Essex Skipper. I was unable to confirm a definite Small Skipper in the few minutes I was there.
I have been keeping butterfly records for the area on and off since the 1980s and if you read some of my day counts for the Marsh from the early eighties, you would think that they were for somewhere completely different. No Speckled Wood, Ringlet, Gatekeeper (Essex Skipper! - you would have to be kidding) - but hundreds of Small Heath, Meadow Brown and even a few Wall Brown butterfly (locally extinct now?).
|A Wall Brown Buttefly - happy days on the dam at Chasewater, now long gone?|
Why when butterflies colonise and area do they have to replace existing species? I can understand it with birds. There is competition for territories, nest spaces and food etc. For example, some people fear that the colonisation by Ring Necked Parakeet will mean a decline in woodpeckers (I don't) . But Butterflies don’t need to compete for any of these things but still we see our long-standing species declining and being replaced by interlopers from the south.
Meadow Brown are still about but in nowhere like the numbers they used to be. Small Heath and Dingy Skipper are hanging on by a thread but Ringlet and Gatekeeper are everywhere. To put that into perspective, in the early 1980s when I started seriously taking an interest in butterflies, I would have had to go to Worcestershire to guarantee seeing a Ringlet or a Gatekeeper.
I am aware that thermoclines are a factor for these species and that with global warming these features are gradually slipping northwards but can that really be such a significant factor in dictating which species thrive and which decline?
I am sure someone must have done some research into this phenomenon but I have not been able to find anything specifically relevant to this issue, so if anyone out there is in a position to address my perplexity, I would be more than willing to learn and pass it on to you lot! Any Takers? - No sensible opinion will be discounted.
Have a good week all - Chaz