It's Blog Action Day 2009

It's Blog Action Day 2009, and these are the latest pictures of my swallowtail butterfly caterpillars Basil and Bob — now preparing to pupate. Very exciting. This year Blog Action Day is about climate change, and I'm proud to have Basil and Bob helping me on this.

Let's think of caterpillars as among the forgotten victims of climate change. It goes like this: as the world warms, the characteristics of habitats change. Spring comes earlier perhaps; the patterns of the rains change; winter comes later and is milder, or the cold snaps are fiercer and at the wrong time. All this plays havoc with the butterfly's (caterpillar's) life cycle. Butterflies lay their eggs on a specific food plant, so that when the caterpillars hatch they can begin to eat immediately. They need to eat and eat and eat for weeks on end — and they need to eat that specific plant. (Basil and Bob ate a lot of my fennel patch.) If the plant's life cycle is altered because the climate is warmer, say, or wetter — well, the caterpillar loses its source of food, and can't survive. Butterflies can expand or move their habitats and colonize where the climate is more favourable relatively quickly, but plants take years or decades to move any significant distance, for deeply obvious reasons. (Ok: no feet.) Plants will lag behind animals in moving as the climate warms; animals will lose food sources and plants will lose pollinators and seed distributors. Whole food chains will be disrupted in subtle but far-reaching ways.

I'm not much of a scientist, but it hardly needs saying that if caterpillars disappear, then so do the creatures that feed on them, and so on down the line. On this green planet we're all linked together. Nothing, really, is too small to be left unconsidered. So, save the caterpillars: if they go, we go — only more noisily, and with a whole lot more pain.