Monday, 6 July 2009

Crossing the Line

This caterpillar was saved from squashing yesterday by Penny, and I was saved from being the squasher. If its luck continues, there will be one more Peacock butterfly in the world. We were walking along the old railway track from Easby abbey to Richmond, and I'd stepped aside to let some cyclists past when P grabbed me and stopped my boot coming down, splat. It was one of five we met, all crawling rapidly across the cindertrack and all but one in the same direction at more or less the same angle. (Sadly, a sixth was squashed, I fear by one of the cyclists who would need Grade A* in the Cycling Proficiency Test to anticipate such things).
When I kept caterpillars as a boy, I noticed how restless they became near pupation - hardly surprisingly; talk about 'the change' ! - and they often went on the longest possible tour they could manage in captivity. I think that's what was happening here, although it is interesting that they almost all seemed determined to go in the same direction. Remarkable, really, that something should impel them to leave the safety of their foodplant, thick and safe clumps of nettles, to cross a sort of Gobi desert full of the hazards I've described (and clear from the picture at the top, I think), presumably to chrysalise in the nettles on the other side. We gave ours a hand into the nettles, as shown in the second pic, where I hope it stayed, although it was still very much on the go. A sort of caterpillar version of the Protestant work ethic? Or something much deeper? Anyway, if you live within reach and want to keep a catty to pupation and watch the magic of its emergence as a butterfly, the Richmond railtrack should provide you with a few. It's a lovely walk, looping back on the other side of the river Swale. Here's what they turn into, courtesy of Mrs Cooke of Michigan State University, although you can see some others too if you scroll manfully down the blog.

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