The High Brown Fritillary (Argynnis adippe) Butterfly might have a new place in a beautiful wooded valley on the Devon coast thanks to a project held in the UK to save them.
According to conservationists, some changes to woodland management, like the abandonment of coppicing, and climate change, contributed to the decline of this kind of butterfly for the last 50 years.
People’s Postcode Lottery gave £100,000 to The National Trust in order to improve 150 acres of lowland heath and wood pasture at Heddon Valley on the north Devon coast to the condition as the new habitat for these butterflies.
Moreover, some others butterflies such as the Health Fritillary and birds like the nightjar and the Dartford warbler might also get benefit from this transition.
Matthew Oates, a National Trust nature expert and butterfly enthusiast, claimed that“ we have witnessed a catastrophic decline of many native butterfly populations in recent decades but initiatives like this can really help to turn the tide.”
The high brown fritillary can be seen over the tops of bracken or low vegetation in woodland clearings or on flowers such as thistle and bramble. It is characterized by its orange and black wings and orange ringed “pearls” on the underside of the hindwings.
This kind of butterfly widespread around England and Wales, however, in the 1950s they suffered a drastic decline and nowadays are found in 50 sites. These sites include Exmoor; other strongholds include Dartmoor in Devon and outcrops of limestone at Morecambe Bay.
Its eggs are laid on leaf litter, on dog violets or among moss growing on limestone outcrops. And its larvae hatch in early spring and spend long periods basking on dead bracken where there is little grass cover or in short, sparse vegetation.
The microhabitat has a temperature of 15 to 20°C higher than in surrounding grassy vegetation, so it allows the larvae´s fast development even in cold weather. The larvae have feathered brown spines, giving them the appearance of dead bracken fronds.
Another positive change that Heddon Valley brings about is that more scrub might be cleared and pathways cut through the bracken, as a consequence the butterflies can move through the landscape.
As the butterflies need a considerably large area to flourish and they are quite often found feeding far from the breeding spots, the swailing technique, which is the controlled burning of the heath, is used to help them.
The Butterfly Conservation’s senior regional officer Jenny Plackett stated that:“Heddon Valley supports the strongest population of high brown fritillary in England, but even here the butterfly remains at risk, and ongoing efforts to restore habitat and enable the butterfly to expand are crucial to its survival.”
New funds from the People’s Postcode Lottery to the National Trust Project aim to include restoring wildflower meadows along the Durham coast to help ground nesting birds such as skylarks and lapwings.