Silver-studded Blue butterflies were released in the UK for the first time in 10 years in an attempt to save the species from extinction.

Fifty female Silver-studded Blue butterflies were released released on Ockham Common, Surrey by rangers from the Surrey Wildlife Trust. 

The Silver-studded Blue butterfly (Plebejus argus) was once common across the UK, but has declined dramatically over the last 30 years. It is now extremely rare and has become confined to small, fragmented heathland areas. Silver-studded blues are a sedentary species and only travel an average of 30m in their lifetime (1km is their maximum). Barriers such as pine trees can stop the butterflies from moving from one area to another. This decreases the population and gene pool, so relocation programmes are then needed to ensure the survival of the species. 

This release by Surrey Wildlife Trust (which was made in co-operation with Butterfly Conservation, English Nature and Elmbridge Borough Council) was the first to take place in UK for 10 years and the first ever in Surrey. 

The butterflies became extinct from Ockham and many other areas of Surrey over ten years ago. There are only 14 sites left in Surrey that actually support the Silver-studded Blue. The only other places where official releases of Silver-studded Blue butterflies have been made are in East Anglia and in Wales. However, these were more for research reasons rather than conservation motives.

The decline in the butterfly population started with the arrival of the Industrial Revolution, when the UK’s heathlands changed dramatically. The industrial changes led to a reduction in the use of heathlands and an urbanisation process that tempted people off the land. The heaths fell into disuse and rapidly became choked with scrubby species. Heathland was also adversely affected by the planting of conifer plantations. This is what befell much of Ockham especially in the period just after the First World War and the butterfly finally became extinct on Ockham in 1992.

Surrey Wildlife Trust ranger James Adler said:

"Silver-studded Blue butterflies are already extinct in Scotland and some parts of the Midlands. The population has suffered a dramatic decline since 1945 due to the loss of suitable heathland habitat. This is a very exciting project. They are a good indicator species of successful habitat management and we hope the population will increase steadily. We will continue to monitor the butterflies to ascertain population numbers."

If the release is successful, it may to lead to further releases.