Unless you are looking for The Chequered Skipper Pub, Lochaber and North Argyll is the only place in the UK to see The Chequered Skipper, a butterfly with a surprisingly limited distribution. What is so special about Lochaber, and just what is so special about this little butterfly?
Luckily, The Friends of Nevis have been holding a series of events promoting awareness of the wildlife and butterflies in and around Glen Nevis this summer, so we had an ideal opportunity to find out more. We were fascinated by an earlier talk on Spring butterflies by Dr Tom Prescott of Butterfly Conservation and were delighted by an opportunity to attend a day focusing on The Chequered Skipper on May 24th with The Friends of Nevis as part of the Wild Lochaber Festival.
The species was formerly present in other parts of the UK, notably around the woodlands of Peterborough, though was sadly declared extinct in England in 1976. The Chequered Skipper (or simply CS to it's friends) was first recorded in Lochaber in 1939 near Loch Lochy in the grounds of Inverlochy Castle. The Scottish race seems to be quite distinct from the former English race, emerging as butterflies earlier in the year and having a different larval (caterpillar) food plant. Whilst the CS around Lochaber feed on purple moor grass (Molinia caerulea), the extinct southern populations fed on False Brome (Brachypodium sylvaticum). These differences would no doubt have implications for any introduction of the species to former habitats south of the border.
On first thought, you would not think that Lochaber provides such a unique habitat for butterflies, but the wet, mild climate is an ideal habitat for purple moor grass, the food plant of the chequered skipper caterpillar. The Lochaber climate allows purple moor grass to stay greener for longer into the autumn and winter providing the caterpillar with enough sustenance and shelter to survive into the spring. The butterflies are on the wing in the middle May to June and feed on nectar rich plants such as bugle, bluebells and marsh thistles in sunny locations. The males set up territories and can often be spotted on bracken fronds or birch seedlings looking out for approaching females. The expectant males tend to chase after any flying insect/butterfly and this provides a good opportunity for spotting them.
After an interesting talk on the CS we headed out into the field to try and find them. We went up Glen Nevis to the top car park (for An Steall) and, equipped with butterfly nets, went out in search of the CS. This Spring, however, has been quite cold and unfortunately we did not find any butterflies. We did see a couple of moths, including the brown silver-line. Although we did not see any butterflies we did learn how to identify suitable habitat and left feeling inspired to find and record the Chequered Skipper in our local patch of Wild Lochaber.
Although well recorded in Lochaber, there are many gaps in the distribution maps of this species and The Butterfly Conservation Society are encouraging members of the public to get involved in recording the species and extending the distribution records. There has been recent work on modelling habitat requirements for the CS and the top 100 1km square have been identified. In 2012 over 50 volunteers helped survey these predicted sites and many new sightings were recorded. The survey is running again in 2013, so equipped with our recent experience we set off in search of the CS.
Having never seen a CS, we first headed off to Glasdrum NNR in North Argyll where there had been recent reported sightings. The clearings along side the electricity lines running through the lower south facing hills at Glasdrum make an ideal habitat to find CS with purple moor grass edging the woods and plentiful nectar plants in the sunny 'rides'. Before too long we were delighted to see a couple of genuine wild chequered skippers as well as the beautiful Pearl bordered fritillary and specked wood on the woodland edge.
Although not conducting intensive surveys we are constantly on the lookout for CS, equipped with our new field craft experience. Amazingly we spotted a chequered skipper in our front garden in Moidart this weekend. That's one of the many reasons we're just Wild About Lochaber.
For more information, or to take part in the CS survey please visit www.butterfly-conservation.org/chequeredskipper.
Andrew & Jayne