Britain's most endangered butterfly, the high brown fritillary, has fallen in number by more than 90 per cent over the past 40 years, surveys show.
Before the Second World War, the black, white and golden butterfly was a common woodland species, but today there are only 51 small sites where it is known to survive in the UK, although it remains common in southern Europe. Its strongholds here are Dartmoor, Exmoor, Herefordshire and the southern edge of the Lake District.
Like several other much-reduced butterfly species (five have become extinct in Britain over the past two centuries) it flourished in traditionally managed woods. Every few years a large part of the wood would be cut for coppice poles, creating sheltered areas where the fritillary caterpillars could bask in the sun after they hatched in March, and where they fed on the leaves of violets. But coppicing has been largely abandoned, leaving woodland too shady and cool for the larvae.
The high brown fritillary also needs bracken to cling to, but not so much that the violets are swamped. The right balance is maintained by cattle and Dartmoor ponies which trample the growth in their search for grass. Today, however, the plant is often controlled with weedkiller.
The fritillary is one of 116 endangered or fast-declining British plant and animal species covered by rescue plans drawn up by a Government steering group, which proposes that the butterfly should return by 2005 to 10 of the sites from which it has recently disappeared.
The wildlife group Butterfly Conservation is finalising a UK action plan for the species which forms the basis for the steering group's proposals, costed at pounds 21,000 a year. Private landowners, the group says, need to be informed on the needs of the species. If they receive one of the Government grants for woodland and countryside improvement, then that should be conditional on their using butterfly-friendly land-management methods to allow the species to re-establish itself.
The fritillary may appear to be a delicate, fussy insect, butlittle more than half a century ago it was well able to co-exist with humankind; it is we who have changed, not the butterfly.Reuse content