In recent years, an increasing concern has been caused by the decline of butterflies in Britain. Almost half of the 59 resident species have reduced their ranges over the last 150 years, and five species have become extinct: Black-veined White (Aporia crataegi; c. 1925); Large Copper (Lycaena dispar, c. 1851); Mazarine Blue (Cyaniris semiargus, c. 1903); Large Blue (Maculinea arion, c. 1979); and Large Tortoiseshell (Nymphalis polychloros, 1980s?). Many of the remaining butterfly species continue to decline nationally or even have become extinct locally on many sites. One of such species is the Silver-studded Blue (Plebejus argus), which is scarce elsewhere in the UK with a high extinction rate (evaluated as 25%): i.e., the species no longer occurs in about a quarter of the localities from where it was recorded in the 1970s. In the UK, this species declined most severely from 1950 to 1980, but with relatively few extinctions occurring between 1980 and 1985 (data by Warren, 1993, for Central Southern Britain).
The main reason for extinction/declining of this and other butterfly species in the UK is a combination of habitat loss and fragmentation/isolation, and changes in habitat management (especially, in Forestry Commission and Public Authority sites). Butterflies are known to be highly sensitive to environmental changes and therefore they often decline whilst their larval food-plants are still widespread and abundant. However, any changes in butterfly populations are to be seen as early indicators of habitat changes that in the future will affect many other wildlife groups.
The Silver-studded Blue is more usually associated with heathland habitats, and a number of regional nature reserves have been specifically established to protect it. One of such sites is the Prees Heath Common Reserve (Shropshire), the last sanctuary for the Silver-studded Blue (Plebejus argus) in the Midlands.
Stephen Lewis, Officer at the Prees Heath Reserve, visited the Manchester Museum on 19/12/2014 in order to study historical records of the Silver-studded Blue from the Midlands on the basis of museum specimens. He also gave us a short interview about the conservation of the Silver-studded Blue in Shropshire (see below).
A more complete story of the Silver-studded Blue butterfly at the Prees Heath Common Reserve presented by Stephen Lewis can be seen in the following short video.
If you are interested in British Butterfly Conservation (the British Butterfly Conservation Society) and their currently formulated strategy for British butterflies please visit the society’s site.
Further reading:
Warren, M.S. 1993. A review of butterfly conservation in Central Southern Britain: I. Protection, evaluation and extinction on prime sites. – Biological Conservation, 64, 25-35; pdf-file online.
Warren M.S., Barnett L.K., Gibbons D.W. & Avery M.I. 1997. Assessing national conservation priorities: an improved red list of British butterflies. – Biological Conservation, 82: 317-328; pdf-file online.
Entomology Manchester 