Here's a blog written by Tom, one of our warden interns.
Leighton Moss is well known throughout the country for all the impressive wildlife that relies on it. Everyone knows about the bitterns, marsh harriers, otters and bearded tits, but not as many people are aware of the work we do elsewhere in the surrounding area. Warton Crag is an impressive ridge of limestone grassland and scrub that provides amazing views of the Lake District and Morecambe Bay. With mossy outcrops of bare limestone and gnarled hawthorn trees, it is home to croaking ravens and peregrines; bounding stoats and deer. But the animals that are the reason for the ecological importance of this habitat aren’t birds or mammals; they are butterflies.
Morecambe Bay is one of the last remaining strongholds for a number of species of butterflies in a group called the Fritillaries. Two such species are the Pearl Bordered Fritillary and the High Brown Fritillary. The habitat they require is very specific: they are ‘edge specialists’; this means they like semi-shaded areas such as that found at the edge of a woodland or in a clearing or glade. This is because the foodplant of the caterpillars (usually dog violet or, in the case of limestone areas such as Warton Crag, hairy violet) grows in these places. Historically, this kind of habitat would have been incidentally maintained by the practice of coppicing – clearing areas of woodland on a cycle of between one and two decades to provide a renewable source of wood fuel. This practice has declined rapidly since the industrial revolution and the widespread use of coal as a fuel, and as a result so too has this important habitat.
The lack of suitable habitat for these animals is cause for concern. This is the reason why at Leighton Moss we are doing all we can to recreate the conditions in which they can thrive. The scrubby woodland, areas of bracken and population of hairy violet that has developed on Warton Crag is excellent for these butterflies, but as I mentioned earlier, they are edge specialists, so if you increase the area of woodland edge, you increase the suitable habitat! Enter the Leighton Moss reserve team. We have spent the last few winters clearing ‘rides’ – linear glades – through the scrub using a cut and burn technique. However, this requires a lot of manpower and we rely heavily on the help of volunteers.
So if you fancy spending a day enjoying the fresh air and beautiful views of Warton Crag, meeting some new people, while getting some exercise and contributing to the survival of these endangered butterflies, then get in touch! The next work party will be going out on Saturday the 18th of February. Everyone’s welcome, with no previous experience necessary.
For more information, you can contact me, Tom Pinches, by e-mail: thomas.pinches@rspb.org.uk or by phone: 01524 703 014.