To increase chances of a successful reintroduction, 10 adult butterflies were released into the prepared site on the Calke Estate on Thurs 23 May 2019. It’s the first time the Grizzled Skipper has been seen at Calke in 50 years. Ken Orpe, the Butterfly Recorder for Derbyshire, said: ‘I began working on this idea with the National Trust around five years ago, so to see the butterfly back in the county is just fantastic and shows what working in partnership can achieve.’ The Grizzled Skipper is identifiable by its black and white markings, and can be spotted basking in the sun between May and early July.
Butterfly project at Calke Abbey
The Grizzled Skipper was recorded in the wider Calke Estate during the 1940s and 50s. Over time, tree and shrub cover increased in the area, closing off much of the open 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 estate.
Preparing for the Grizzled Skipper
Due to its favourable geology, the Calke Estate was suggested by Butterfly Conservation East Midlands as the first site in Derbyshire to reintroduce the Grizzled Skipper.
" Before this lovely butterfly disappeared from Derbyshire in 2007, Calke 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."
Work has been on-going in the chosen area for many years: several trees were removed to open up the area, and Hebridean sheep were introduced to graze off the regrowth. This encouraged the growth of grasslands and plants that love the calcium-rich soils, such as the Common Spotted Orchid and the Fragrant Orchid.
Bringing the butterflies to Calke
In early 2018, more work was done in the area to prepare for the arrival of the Grizzled Skipper. The ranger team at Calke removed some more tree cover from shading the spoil heaps and banks, creating lots of sunny areas for the caterpillars to develop and thrive.
In order to encourage the growth of wild strawberry, the caterpillars’ main food plant, the grass banks were raked to open up bare soil, and wild strawberry was introduced into areas that didn’t have any. Work is continuing in this area to ensure it remains an ideal habitat for the Grizzled Skipper.
In May 2018, 10 adult butterflies were released into vegetated areas on the Calke Estate, with another 11 eggs placed in secure conditions, to be released in spring 2019. We’ll also be bringing more butterflies to Calke in 2019 to increase the chances of a successful re-introduction.
How will we know if the re-introduction was 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.
To see how the Grizzled Skippers are getting on, see the timeline below for updates.
Looking after the Grizzled Skipper
The project to reintroduce the Grizzled Skipper is in partnership between Natural England, Butterfly Conservation and the National Trust.
We’re also working with Butterfly Conservation’s Mike Slater, who’s been involved with successful wildlife reintroductions in other counties. Speaking in 2018, Mike 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 Calke Estate in June this year. This really is a great opportunity to bring this butterfly back to Derbyshire. "
23 May 19
More Grizzled Skippers are released at Calke
11 May 19
The first butterflies emerge
In 2018, 11 Grizzled Skipper eggs were placed in secure conditions, in the hope that they would grow into adults ready to be released into the Calke Estate in early 2019. This week, the first butterfly emerged and was released into the prepared site on Sun 12 May. Since then, two more butterflies have emerged, and we’re hopeful to see more butterflies popping up in the area soon!
01 Jun 18
The Grizzled Skipper arrives
With all preparations complete, the plan was to relocate the Grizzled Skipper eggs from Warwickshire in early June, but the hot spell throughout May caused the eggs to hatch earlier than expected. After a last-minute change of plan, 10 adult butterflies were transported to Calke and released into vegetated areas, with another 11 eggs placed in secure conditions, where they will grow into adults and be released into the Calke Estate next year. Following a bout of heavy rain, the rangers returned to the relocation site the next day to create further egg-laying sites, by placing stones and pieces of wood underneath wild strawberry plants. This is called ‘stone seeding’ and provides better conditions for the butterfly to lay eggs. At this stage, it’s difficult to measure the success of the reintroduction of the Grizzled Skipper, but the ranger team at Calke are hopeful to see more of this rare butterfly next summer.