5th May 2020
For around the past 10 years, in the middle of June lepidopterists (butterly-lovers!) and photographers are often seen sporadically sweeping the bracken-covered steep slopes of the Heddon Valley (National Trust) in search for this rare UK butterfly. This year (2020), it was noticed as an adult mid-May - I swore I wasn't seeing things! Butterfly numbers in general have been declining at a fast pace since the 1970s...
What is the high brown fritillary (Argynnis adippe)?
As an adult, this medium-sized orangey-brown butterfly (~70mm wing span) has black chequered style markings and a rapid flight movement - the underside is the giveaway - a brown 'eyelet' sits high on its underwing when they close their wings during feeding.
Adults feeding is specialised on bramble flowers and knapweed, on south (to southwest) facing bracken slopes, dense with common-dog violet for the larvae to feed on.
The dark green fritillary (Speyeria aglaja) is somewhat mistaken as the high brown, however there is no eyelet - instead, the underside is a dusty mossy green colour.
The shape of the upper wings are different - dark green have convex wings, high brown are concave "cave in" !
Where is the Heddon Valley?
In the south west of England sits the beautiful coastal and moorland Exmoor National Park. The Heddon Valley is to the far west of Exmoor, between the towns of Lynton and Combe Martin.
It is the UK's deepest river valley running to the sea, dominated by over 400,000 sessile oak trees, some over 100 years old, with the Hunter's Inn (National Trust) proudly taking centre stage - hotel - bar - restaurant POSTCODE: EX31 4PY
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