Spring Butterflies in Lochaber

Published: 12th June 2017

At this time of year our attention becomes fixed on our local butterfly populations, particularly those of the chequered skipper. Found only within a thirty-mile radius of Fort William, these handsome little yellow and chocolate brown skippers are a major draw for butterfly enthusiasts from around the UK. As well as, hopefully, showing guests where these can be found we also try and do our bit by monitoring the population along local transects. All of this, is of course, weather dependant. Transects, for us, can only be walked when we are not entertaining guests, and then the weather needs to play its part. After a wonderful early dry, sunny patch in the first three weeks of May, the weather has turned decidedly mixed for the skipper season. Fortunately, these doughty little butterflies do not need much sunshine to appear, and breaks in the clouds have been accompanied by sudden abundances of butterflies of many species. We have also found that butterflies have been much easier to photograph on cloudy days with bright spells. On the one day we achieved close to record temperatures and bright sunshine, fritillaries, in particular, were flitting about at rate fantastic, and rarely stopped to nectar. Skippers also took up territories and were very quick to fly up to see off intruders. This weather has proved the exception rather than the norm, and after an early start to the season, conditions of cool, cloudy days are more reminiscent of last year, when transects had to be walked in rather suboptimal conditions. A notable difference from last year is that the spring flowers have been over very quickly, and that bluebells have long gone over from most coastal locations, such as Glasdrum

As I write skippers are still flying, and have been in good number in most locations visited, but particularly in Glen Loy, where bluebells are still flowering in sheltered locations. Just as notable have been the small pearl-bordered fritillaries, which seem to be having a great year in Glen Loy. They seem to favour nectaring on bird’s-foot trefoil, which has also made an early appearance. Conversely, pearl-bordered fritillaries appear to be in short supply, but we did see good numbers of these earlier butterflies nearby at a site near Loch Arkaig, and a few at Glasdrum. Small heaths also seem to be doing well this year, with plenty flying in the glen. In all we have seen a total of 15 different species of butterfly in the last couple of weeks; not at all bad, considering the patchy weather. These have included the first marsh fritillary of the year at Cuil Bay on 26th. May, and a few very early dark-green fritillaries near Salen on 7th. June. The first common blues are also out. Perhaps the most surprising was a rather faded painted lady on Muck. Orange-tips were still flying today (11th. June), and green hairstreak are still accompanying the skippers.

Moths have also been good, mirroring the fortunes of local butterflies. Large numbers of argent-and-sable are flying in the glen, as well as small argent-and-sable. I was particularly pleased to find a couple of Mother Shiptons nectaring along with blues and fritillaries in the glen, a first for my local list. Another attractive moth that we found on our transect walk is the beautiful purple and gold Pyrausta ostrinalis, rather a rarity in our part of the world. We also found a huge eggar female accompanied by a hopeful male in rather unpromising conditions at Creag Meagidh. Chimney sweeps have just hatched and can be seen in great numbers locally. Other moths of note that we have caught in the trap have included a striking saxon, green silver-lines, Welsh wave, satin lutestring and the ever-popular elephant and poplar hawk-moths.