91热爆

Janet Sumner visits the Cotswolds to see the fabulous Adonis blue butterfly. It was once extinct in the area but has made an astonishing comeback. Matthew Oates is Britain's butterfly guru and shows Janet around. This countryside is getting better as an Adonis blue habitat, but isn''t quite as well grazed as they would like it. The male Adonis is an electric blue colour, very vivid and very distinctive. Females are brown or even black. It is fairly early in the morning, so males are searching for virgin females. Virginity doesn't last long in butterflies! They only use a single species of plant - horseshoe vetch - to breed on, and only in fairly short turf. But that's not all the caterpillars need: they have a strange association with ants, which protect the caterpillar and chrysalis from predators and get a sugary solution from the caterpillar in return - a symbiotic relationship. For half a century the Adonis blue disappeared from the Cotswolds, but careful management by the National Trust and the reintroduction of grazing livestock have helped them make a comeback. Cows have been instrumental. The cattle were introduced in 1999 to look after the plants and butterflies that were already there, and unexpectedly within six years the Adonis blue reappeared. The cattle have created the right environment and got the grass into the right condition for the fussy butterfly.