Butterfly Frontier Lands
- 7 Aug 06, 10:31 AM
Submitted by PEuT reporter Gordon Radley
What a nice change- a couple of days out of the intensity of a TV news studio and a chance to go to work in T Shirt and shorts. I am well chuffed-doing a story on global warming on the two hottest July days ever recorded. Also an opportunity to look at and find out about some of the country’s most beautiful creatures. Imagine an English summer’s day without a butterfly fluttering by? With global warming though things could change.
First stop York University to meet Chris Thomas, an expert on the way butterflies are responding to global warming. Butterflies are a useful tool in the global warming story because of their quick life cycle, their sensitivity to temperature and the fact that they can move from area to area relatively fast. Although it seems like there are plenty of butterflies around on these long lazy summer days only 12 of the 60 UK butterfly species are actually doing well. Our reason for choosing the area around York is that it is a kind of butterfly frontier land. The success stories have spread northwards to this area in response to shifts in the climate but on an alarming note some of the northern species like the Large Heath are retreating rapidly northwards and have their last stand in this area. The Comma which I remember so well from my childhood is doing well and so is the Speckled Wood but species like the Mountain Ringlet aren’t doing well at all. Chris shows me maps and tables of the shifts in ranges of these species and many other insects that are responding to increasing temperatures and longer summers.
I went to Chris’s office with a view to learning more about two or three butterfly species. I came away with an understanding of the global implications of climate change on a number of indicator species and also a sense of Chris’s very real concern about what appears to be happening. At times there was almost a hint of panic in his voice. Anyway much more on Chris and his research in Planet Earth under Threat. Oh and discover why some of Britain’s crickets are mutating to take advantage of a warmer climate!
The next day we meet scientist Jane Hill to find out more about the winners and losers in the butterfly world as they adapt to climate change We go to a York cemetery to see the Speckled Wood, one of the ‘winners’ which is spreading north rapidly. It’s another balmy day and within a few minutes the Specked Woods oblige- one even landing on the producer’s clipboard. It is a beautiful brown colour with lots of tiny cream spots It likes the dappled shade of the cemetery and according to Jane is territorial- and judging by what I saw aggressively so- though I can’t claim really to have seen a butterfly fight .
During my interview with Jane Hill I was fascinated to discover that at this northern frontier of their spread northwards the butterflies are genetically different. In some individuals the wing muscles are stronger and they can fly further. Apparently the downside for the species is that the female then lays fewer eggs. ‘How do you know its muscles are stronger?’ I said to Jane. Jane obliged by thrashing her net down of one bemused butterfly. She then held it gently and pointed out to me that the thorax was bigger in this individual than is the norm- to accommodate the bigger muscles.
That afternoon we travelled to Thorne Moors National Nature Reserve in Humberside to try to find the Large Heath butterfly which is now at the southern edge of its range here and is retreating north at an alarming rate. For many years Fisons extracted peat for professional and amateur use from this area. During the first part of our walk with Jane Hill in search of the Large Heath I was struck by the ugliness of this derelict industrial site- so ugly it almost reached the point of beauty. Then when we got into the bogs proper I was absolutely stunned. I have never been to a bog that looked both parched dry and wet at the same time. Bog cotton, heather, grasses and shrubby birches- everywhere so so flat. The Large Heath has been able to hang on this far south because of the very specialised nature of these wetlands which can sustain the larval food plant, Cotton grass. However, today Large Heaths were thin on the ground - Jane Hill may have sighted a couple but I didn’t see any. Disappointing but also appropriate since we came here to find out about a beautiful butterfly fighting for survival because of global warming and its absence was very likely due to the incredibly hot weather.
Much more detail on our hunt for the winners and losers in the UK butterfly world in Planet Earth under Threat.
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Global warming will not effect crops at all, none will ever fail.
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Great article.
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