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Cumbria's Butterflies Month by Month

By Peter Wilde


Credit Peter Wilde

The first butterflies on the move are those that overwinter as the adult. Peacock and small tortoiseshell may be seen on the occasional warm day in March, but brimstone and comma are rather tighter hibernators and require temperatures to remain high for several days to tempt them out. Small tortoiseshell and peacock occur throughout the county. Brimstone are largely confined to the south of the county, often associated with areas where buckthorn was grown to make the charcoal for gunpowder. The comma is a recent coloniser and is spreading throughout the county. By the month end holly blue may be seen, but is scarce north of Grasmere except round Carlisle. Those speckled wood that have overwintered as pupae also begin to emerge - this is a rapidly spreading species, but still most likely to be seen in the south and west of the county. Depending on the warmth of the spring the odd red admiral may have found its way into the region from the south or, more recently with mild winters, possibly over-wintered here.



Credit Peter Wilde

May is the month of "whites". Large white, small white and green-veined white put in their first appearance of the season, but the delightful orange-tip patrols many Lakeland hedgerows for the next few weeks only. Green-hairstreak colonies can be quite large throughout the month, but they are generally restricted to lowland heath and the drier edges of bog. By the last week the first generation of wall, though never numerous, may be seen around the coast, but rarely more than 15 km inland. The 'piece de resistance' of the month must be that 'flying penny' the spirited Duke of Burgundy. There is a small and vulnerable number of colonies on the limestone at the head of Morecambe Bay, but this is a seriously threatened species both locally and nationally. By the end of the month the first specimens of the bright orange and moth-like large skipper can be found on almost any small bit of waste grassland around the county. Finally, one member of the 'blue' family (although not outwardly blue) - the attractive small copper - makes its first appearance this month. It will reappear in late July and can then be found throughout August and September.



Credit Peter Wilde

By the beginning of the month marsh fritillary should be on the wing. This once common species is now restricted, after much land drainage, to a handful of re-introduced colonies in the county, all on private land except at Finglandrigg Wood NNR. Also as June opens, pearl-bordered fritillary numbers rise quickly. This species is found only around Morecambe Bay and has retreated eastwards in recent years (mirroring its steep decline nationally). The rather drab and easily missed dingy skipper should be at its peak by the month end, but it is now largely restricted (thanks to agricultural improvement) to dunes, cliffs and old quarries where its foodplant, bird's-foot trefoil, still grows. The same coastal sites and foodplant also support huge numbers of common blue; males are blue but the female of this species is more usually brown with orange spots. The related plant, kidney vetch, is host to the small blue, but it is found only around Maryport and Workington. As numbers of pearl-bordered fritillary decline towards the month end, its smaller cousin small pearl-bordered fritillary takes over. This, probably the county's most successful fritillary, can be found throughout the county at many sites, often moorland and marsh with tree shelter where marsh or dog violets grow. The small heath, found in many different grassy habitats from dune slack to high fell, now appears continuously for the next three months. By the month end the first northern brown argus are about on the Morecambe Bay limestone, although they may be a little later at the Trust's Smardale Reserve. The mountain ringlet, a species of the highest fells, is normally most easily observed on sunny days during the last two week's of this month and the first week of July (although at Irton Fell it may have emerged by the beginning of the month). Grayling may begin to emerge in the south of the county by the end of this month; it is a very coastal species and appears to have suffered a serious decline in recent years. Where it occurs, it can be very abundant (as on North Walney NNR or the Channelside slag banks at Barrow) and continues to fly throughout July and well into August.



Credit Peter Wilde

Meadow brown is the commonest butterfly of the month, but for the connoisseur July is large fritillary time. The gorgeous high brown, dark-green and silver-washed fritillaries emerge in succession and overlap in flight period, making identification a challenge. The endangered high brown is doing well at the head of Morecambe Bay (thanks to a lot of conservation effort), but the dark green is more of a wanderer and can turn up anywhere in the county, especially round the coast; it seems to be one fritillary that is increasing in numbers. Our largest fritillary, the silver-washed, is a treat to watch as it glides around the sunlit clearings it has colonised around the base of Whitbarrow. Small skipper seems reluctant to spread into Cumbria, but sightings are now regular on the southern and eastern borders. The large heath is on the wing throughout the month on raised bogs in both north and south. The ringlet, a woodland species of the month, is an exception to the norm in that it is one butterfly found in the north of the county but not normally in the south. Scanning the tops of oak trees in the second half of the month may bring the reward of sightings of purple hairstreak. It is less widely recorded than its relative, the green hairstreak, probably because it passes unnoticed in its tree-top home - look on the south side of woodland oaks in the afternoon. A "southern" butterfly, the gatekeeper, has been spreading rapidly up the west coast and across the south of the county in recent years and has now reached the north; where it occurs it is often numerous. By the month end speckled wood numbers are beginning to peak as all the broods come together to produce adults.


Credit Peter Wilde

By now second broods are emerging of species seen earlier in the year - small tortoiseshell, peacock, red admiral, comma and wall for example. This is the month of the buddleia which attracts these familiar garden visitors. The "will-they-won't-they" painted lady can be abundant or totally non-existent - depending on whether weather (!) patterns in the spring brought an immigration to the county. Equally, two other migrants, clouded yellow and Camberwell beauty may turn up in August, the latter usually only in ones and twos in Cumbria. Clouded yellow may be abundant one year then not seen for several years! The elusive holly blue has it's second spell on the wing in early August for two or three weeks - look this time around ivy, especially in old established gardens and churchyards. Scotch argus can reach almost 'plague' proportions on Arnside Knott in the first half of the month, but curiously turn their noses up at every other patch of land in the county, except at the Smardale Reserve where it appears a few days later than at Arnside.



Credit Peter Wilde

As the season fades away the most numerous species is usually the red admiral. Migration southwards through the county is now well under way. If there is an Indian summer, Small tortoiseshell, peacock and comma will hang on and feed up before hibernating. Species with second broods like small copper, common blue, wall and speckled wood may still be about. However the season ends rather sooner in Cumbria as temperatures fall - third broods of species which can occur further south are rare here.


For those who have been counting, the grand total of species found in the county is 39 - a remarkable total for a county in the north of England. One or two other species, including white-letter hairstreak, have appeared in small numbers in the last few years, but it remains to be seen whether they become established in the region. Sadly, several species formerly recorded in South Cumbria are now extinct in the region. These include (with year of last record):

Brown hairstreak (1920)
Silver-studded blue (1939)
Large tortoiseshell (1945)
Wood white (late 19th Century)

Photos: Peter Wilde


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