The Glanville Fritillary Butterfly is quite common on the south coast cliffs of Guernsey in May and June. Its caterpillars are black and spiny with a red head and feed in groups in webs on plantains in the autumn and spring. The caterpillars hibernate in their webs, but in the last instar they separate and can often be found walking over the cliff paths. The butterfly is common in Alderney but extinct in Sark and Jersey. In Britain it has long been known from the Isle of Wight and there is some evidence that it is spreading along the south Coast of England.