Managing the land
After observing such a dramatic decline, it was apparent that there was little option other than direct and robust habitat management to try and restore the fortunes of the Heath Fritillary on Exmoor.
Key to the butterfly’s recovery would be the abundance of Cow-wheat which had since been shaded out by competing vegetation and bracken litter due to under-management of their favoured sites.
Cow-wheat is an annual plant, semi-parasitic on bilberry and the key larval food plant for the Exmoor heath fritillaries.
Positive results
Since 2005 the Heath Fritillary has continued not only to increase in numbers at key sites but also re-colonised some historic sites, particularly in the combes on the lower slopes on the northern side of Dunkery Beacon.
During 2020, not only have good numbers been recorded at their key sites but there has also been widespread dispersal of individuals searching out new habitat.
Modern technology lends a helping hand
The Bromford flailbot has quickly become a valuable addition to the Holnicote Estate. This remote-controlled flail mower has allowed the rangers to take a different approach to the management of some of our most valuable sites, from orchards to heathlands.
Flailbot can access remote sites which are hard get to with vehicles and traditional machines. Many of these places would be unsafe to use a tractor on, whereas the flailbot can be used when working on steep slopes and coastal areas with a reduced risk to safety.
On Holnicote Estate our health fritillary population is found on steep slopes in woodland edge habitat. The rangers use flailbot to manage their habitat by breaking up the vegetation, cutting back scrub which allows light in for common cow-wheat, the main food source for the caterpillars.