5 days ago
Butterflywatch: British populations thrive thanks to record sunny spring
It has been a very good year so far for butterflies in Britain, thanks to the sunniest spring since records began in 1910. Dry, sunny weather has helped butterflies get out early, survive for longer than usual and lay plenty of eggs.
The naturalist Matthew Oates noted 36 consecutive days when he saw butterflies on the wing, from Good Friday through to late May – a cheering and increasingly unusual experience in this country.
Lepidopterists are a bit like farmers, apt to grumble about the weather unless it is a perfect balance of sunshine and some rain. Without rain, caterpillar food plants shrivel up and die, and the next generation do not thrive. So the current rains are very welcome, and should ensure emerging caterpillars have plentiful food.
But this bright picture unfurls against much darker big-picture trends. Butterflies are sun-loving animals; global heating should mean British populations are booming, but in fact the opposite has been happening. Last summer was the second-worst year for common butterflies since scientific records began in 1976. For the first time, more than half of Britain's 59 native species are in long-term decline.
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Hopefully this summer sees a big bounceback for British butterflies, but even in good times we must note that these well-studied insects are a bellwether for the global collapse of insect populations. All life on Earth is imperilled unless we take meaningful steps to reduce chemical use, pollution and habitat destruction.
