The Wall gets its name from the characteristic behaviour of resting with wings two-thirds open on any bare surface, including bare ground and, of course, walls! Many people will have come across this butterfly on footpaths, especially in coastal areas, where the butterfly flies up when disturbed, before setting again a few metres ahead.
The basking behaviour of this butterfly allows it to benefit from the full warmth of the sun whose rays shine directly on the butterfly, but also get reflected back onto the butterfly from whichever surface it is resting on. This habit allows the butterfly to raise its body temperature sufficiently high for it to fly. In particularly hot weather, however, such basking is avoided and the butterfly may even retreat to a suitably-shaded spot to avoid overheating.
This species was once found throughout England, Wales, Ireland and parts of Scotland. Today, however, is a very different picture, with this species suffering severe declines over the last several decades. It is now confined to primarily-coastal regions and has been lost from many sites in central, eastern and south-east England. In Scotland it is confined to coastal areas in the south-west of the country. It is also found on the Isle of Man and Channel Islands. This butterfly is found in relatively small colonies that are self-contained although some individuals will wander, allowing the species to quickly colonise suitable nearby sites.
This species was first defined in Linnaeus (1767) as shown here (type locality: Austria and Denmark).
The first generation of adults emerge in early May, peaking at the end of May and early June, or a little later in the north of England and Scotland. They give rise to a second brood that emerges at the end of July, or mid-August further north. There are 2 generations each year and, on occasion, a small 3rd generation may appear in October.
The chart(s) above have been correlated with the phenology plot below, taken from the UK Butterfly Monitoring Scheme. The blue line gives average counts over the full data set from 1976 to date, and the red line gives the average for the last year.
This species is now found primarily in coastal areas, especially unimproved grassland, wasteland, cliff edges and hedgerows.
The primary larval foodplants are Bents (various) (Agrostis spp.), Cock's-foot (Dactylis glomerata), False Brome (Brachypodium sylvaticum), Tor-grass (Brachypodium pinnatum), Wavy Hair-grass (Deschampsia flexuosa) and Yorkshire-fog (Holcus lanatus).
Adults feed primarily on Daisy (Bellis perennis), Fleabane (Pulicaria dysenterica), Hawkweeds (Hieracium/Hypochoeris), Knapweeds (Centaurea spp.), Marjoram (Origanum vulgare), Ragged Robin (Lychnis flos-cuculi), Ragwort (Senecio jacobaea), Thistles (Cirsium spp. and Carduus spp.), Water Mint (Mentha aquatica) and Yarrow (Achillea millefolium).
The male of this species is territorial and will inhabit a particular area, such as a path, hedgerow or roadside verge, waiting for a passing female. Males will typically perch in a favoured position but will, in sunny and warm conditions, adopt a strategy of patrolling in order to find a mate. All passing insects are investigated and rival males will fly high into the air before coming back to the ground a few seconds later.
The female is much more sedentary and the less-conspicuous of the two sexes. After a brief courtship a pair will mate before disappearing into surrounding vegetation. Both sexes are avid nectar feeders and will feed from any available flower.
Description to be completed.
The spherical eggs are laid singly, or occasionally in twos and threes, in various positions, including the leaves of the foodplant, exposed roots and nearby vegetation. Eggs are pale green when first laid, becoming more translucent as the larva develops within. Sites for egg-laying are typically sheltered and warm compared to their surroundings, and include grass clumps, rabbit scrapes and hoof prints from cattle. This stage lasts around 10 days.
After emerging, the young larva typically eats its eggshell before feeding on the leaves of the foodplant. Larvae become more mobile as they mature and will move from plant to plant as needed. Larvae typically feed at night, but occasionally feed during the day. This stage lasts around 4 weeks for those larvae that do not overwinter, and there are 3 moults in total.
The green pupa is formed head down, attached by the cremaster to the foodplant or nearby vegetation and is extremely well camouflaged. This stage lasts around 2 weeks.
No similar species found.
Click here to see the distribution of this species overlaid with specific site information. Alternatively, select one of the sites listed below.
|Abbots Wood, Arnside Knott, Badbury Rings, Ballard Down, Ballydyan, Ballyscanlan, Barnack Hills and Holes NNR, Beachy Head, Bindon Hill, Bingham Linear Park, Bishop Middleham Quarry, Boultham Mere, Brackett's Coppice, Bradfield Woods, Brean Down, Broadcroft Quarry Reserve, Broaks Wood, Bryncelyn Hall, Candlesby Hill Quarry, Castle Eden Dene, Castlehill Point, Clubmen's Down, Cop Lane, Corfe Castle, Crickley Hill, Crook Peak, Dolebury Warren, Draycott Sleights, Drigg Dunes, Durlston Country Park, Eakring Meadows Nature Reserve, East of Cove Farm, East Ord, Fingringhoe Wick, Fleetwood Marsh, Fontmell Down, Frog Firle Farm, Hethfelton Wood, Hexham, Higher Hyde, Hinkley Point Nature Reserve, Hod Hill, Holton Lee, Howth Head, Jerry's Hole, Kenfig Pool, Kingcombe Redholm, Kingcombe Stones, Long Knoll, Lorton Meadows, Lough Bunny, Lough George, Lydlinch Common, Malling Down, Meanwood Park, Mill Hill, Mill Hill Quarry, Monk's Wood, Mynydd Marian, Old Castle Down, Perryfields Quarry, Piddles Wood, Portland Tout Quarry, Powerstock Common, Ringstead Bay, Sand Point, Shipley Station Meadow, St Abbs Head, Steyning Downs, Stoke Camp, Stubhampton Bottom, Tadnoll, Titley Pool, Tophill Low, Torr Works, Tyne Riverside Country Park, Ubley Warren, Wall Common, Walters Copse, Warton Crag, West Williamston Salt Marshes, Whitbarrow Scar, White Sheet Hill, Windmill Hill and Cleeve Prior, Windover Hill, Wiveton Down, Wolla Bank Pit, Wood of Cree, Woolacombe Down|
There has been a severe and worrying decline of inland populations, with most remaining populations now being found in coastal areas. This species is therefore a priority for conservation efforts.
The table above shows the distribution and population trends of species regularly found in the British Isles. The distribution trend represents a comparison between data for the periods 1995-1999 and 2005-2009. The information provided is taken from the Butterfly Conservation report The State of the UK's Butterflies 2011. The UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).
The following links provide additional information on this butterfly.
The species description provided here references the following publications: