Loch Uidh nan Corp, Brackloch (part 2)
We returned to this area north of Brackloch five weeks later, on 26th May 2020. The main objective was to collect more desmid samples for David Williamson.
This time we went straight up the hill north of the road to the un-named lochan (NC116246), taking a panoramic photo of the site from a nearby ridge (photo 12). A muddy pool at the north-west corner, where a tiny burn entered, had palmate newts (photo 13), toadpoles and the medium-sized diving-beetle Acilius sulcatus. Working around the edge of a bed of great fen-sedge we spotted some striking moss capsules on old mammal dung (photo 14), which were later identified as those of the slender cruet-moss Tetraplodon mnioides.
An open area in a great fen-sedge bed yielded the first desmid sample (photo 15) and also a stem of slender sedge Carex lasiocarpa whose short rootlets were clad in brown sheaths, a phenomenon still awaiting explanation. We started down the exit burn, looking for a spot in the sun, out of a slightly chilly wind, for lunch, and found a large boulder on the edge of the burn, which sufficed (NC116248). Whilst we were gathering our belongings up after lunch, we noticed some very colourful objects, rounded and about 3mm long, stacked along a stem of bog myrtle Myrica gale beside the boulder. They looked vaguely entomological, but quite unlike we had had ever seen.
Gwen’s close-up photos (photos 16-17) enabled their later identification, by Stephen Moran, as the skins of female scale insects of the species Eulecanium tiliae. Their offspring over-winter underneath them and were almost ready to emerge. There appear to be no Scottish records on NBN, although it has to be said that the group is not popular with amateur naturalists. Nearby we had our first large red damselfly Pyrrhosdoma nymphula of the year.
We then made our way back down the burn to the edge of the narrows between Loch Uidh nan Corps and An Ruadh Loch to its east (photo 18); taking further desmid samples both in the narrows and the latter loch (NC118250), where further toadpoles were noted. David Williamson has since reported finding an extremely rare desmid in the sample from An Ruadh Loch, of which more later. After leaving the loch-side, we decided to walk up what proved to be a rather a rather dull valley to the south-east, towards Lochan Fearna, the second objective for the day.
Just on the far side of a ridge, a bracken-covered slope (NC121248), presumably also on glacial till, provided a good range of grassland/woodland species, such as pignut Conopodium majus, bluebell Hyacinthoides non-scripta and yellow pimpernel Lysimachia nemorum. Nearby there was an old sheiling with clearance cairns.
This area afforded a good view over a broad wet valley to the east, with conspicuous sloughs of black bog-rush (photo 19), indicating base-enrichment of the water flowing down them. These sloughs were gathered together into quite a substantial slow-flowing burn. A pool in the burn (NC123248) yielded a handful of stonewort Chara virgata and Nordic bladderwort Utricularia stygia for further desmid sampling, and also, incidentally, a large horse leechHaemopsis sanguisuga.
We picked our way rather carefully across a boggy area to the westernmost part of Lochan Fearna (loch of the alder Alnus glutinosa, probably long gone), where a tea break was enjoyed. The loch had two more beds of great fen-sedgeon its margins (photo 20) and a little further south (NC124246) there was a further huge area of great fen-sedge, quite the largest in the parish, which Ian had once before visited, back in February 1993. From there we made our way in a south-westerly direction, around the edge of a large deer-exclosure, and down the exit burn from Lochan Fearna, noting a single frog on the way, until the burn disappeared under the road, on its way to Brackloch.
We had spent five hours on the hill, covered some new ground, recorded all the local amphibians and assorted moths (Angleshades larva, Common Heaths, Northern Eggar cocoon), collected five desmid samples, seen large quantities of great fen-sedge, and as a completely unexpected bonus, discovered some scale insects that were possibly ‘new’ to Scotland.
Note. Since this area appears to be rarely visited by anyone, including naturalists, we have given grid references for many of the landscape features.
Ian M. Evans and Gwen Richards