For a really great summary of the large blue project across the southwest, and a chance to see a picture of Dave Simcox doing field research twenty years ago! have a look at the CEH article produced for the celebrations to mark the re-introductions’ 25th year.
Background to the large blue at Collard
Larvae were introduced to Collard Hill a decade ago and the population has since grown to the point where it is now one of the best sites for this rare butterfly in Europe.
Surveys by Jeremy Thomas from Oxford University and David Simcox of CEH in the 1990s had identified that the key conditions were in place for the large blue to prosper at Collard – south facing warm slope, pervasive wild thyme and an abundance of the rare red ant Myrmica sabuleti. In 2000 CEH introduced 267 large blue larvae to Collard from the Somerset Wildlife Trust’s reserve of Green Down also on the Polden Hills.
The first emergence in 2001 was great a start. However, the road to success is rarely straight and the first few years were a rocky ride with the future in the balance in 2005.
Since then the grazing has been radically changed with different stock (cattle and ponies), a new ridge fence and trough to focus the animals on the slope. With a lot of help from the farmers this has paid great dividends: numbers have increased sharply year on year for the last six years with over 40,000 eggs laid in 2011. Fingers crossed for another good year in 2012!