The Grizzled Skipper was recorded on the Calke Estate during the 1940s and 50s. Over time, tree and shrub cover increased in the area, closing off much of the open quarry floor and banks that contained the butterfly’s food plants, wild strawberry and bugle. Now, the National Trust is working in partnership with Butterfly Conservation and Natural England, to embark on a project to reintroduce this increasingly rare butterfly species to the area.
Looking after the Calke Estate
It is a priority of the National Trust to restore the estate to a healthy, natural environment where all wildlife can thrive.
On the site where the Grizzled Skipper will be reintroduced, several trees have been removed to open up the area and Hebridean sheep were introduced to graze off the regrowth. This encouraged the growth of grassland and plants that love the calcium-rich soils, such as the Common Spotted Orchid and the Fragrant Orchid.
Preparing for the Grizzled Skipper
Due to its geology, the area was suggested by Butterfly Conservation East Midlands as the first site in Derbyshire to reintroduce the Grizzled Skipper.
County Butterfly Recorder, Ken Orpe, said: "Before this lovely butterfly disappeared from Derbyshire in 2007, part of the Calke Estate was an important site for the species and it was once there in good numbers, so it’s very fitting that this was chosen as the location for the re-introduction."
In recent weeks, the ranger team at Calke have removed some more tree cover from shading the spoil heaps and banks. The butterflies need lots of sunny areas for the caterpillars to develop and thrive. We’ll also be raking the grass banks to open up bare soil, to encourage more of the caterpillars’ main food plant, wild strawberry, and reintroducing wild strawberry in open areas that don’t currently have any.
Looking after the Grizzled Skipper
The project to reintroduce the Grizzled Skipper is in partnership between Natural England, Butterfly Conservation and the National Trust and it’s our priority to protect and conserve the area that will hopefully become a home to this butterfly.
The project is also being overseen by Butterfly Conservation’s Mike Slater, who’s been involved with successful wildlife reintroductions in other counties.
He said: "I visited Calke in March and was extremely pleased with the work carried out so far – the project has now been approved and the Grizzled Skipper eggs will be relocated from Warwickshire to the estate in June this year. This really is a great opportunity to bring this butterfly back to Derbyshire."
How will we know if the re-introduction had been successful? Every week, the rangers at Calke complete a butterfly transect – a survey to record butterfly species in the area, and their numbers. The route is walked once a week between 1 April and 30 September, and the results are sent to Ken Orpe, the County Butterfly Recorder.
This year’s transect, which is completed with the help of our volunteers, will give us an idea of what we have now, before we introduce the Grizzled Skipper later this year. It will also help us to monitor how well the Grizzled Skippers do, and allow us to alter our management of the project accordingly. We hope to see lots of butterflies over the summer!
Keep an eye out here for more updates!