Nature Notes from Skye
(and occasionally other places)
Sat 14 Feb 2004
Sunny all day! Went along shore of Varragill estuary from Aros to the Bridge, then down the road to Penifiler, then wandered around on the hill and finally returned the same way. Primarily looking for interesting lichens. As I'm a beginner I'm only bothering with distinctive-looking ones at the moment, as there is more chance of identifying these.
There were a few unseasonal cobwebs among the heather stems near the shore. The white blobs are last year's withered heather flowers which remain on the plant all winter together with the leaves.
The Hard Fern (Blechnum spicant, above right) keeps in even better shape all winter, its green sterile leaves looking very summery. The brown fertile leaf, just behind and to the right of the middle green leaf, with narrow lobes, is more in keeping with the season and merges with the bracken around it.
Wasn't long before I found a beautiful lichen, which turned out to be Cladonia fimbriata (below, left). It was growing on a wet rotting tree stump, on the shaded side.
The right-hand picture above shows the effect of sun and ice on the saltmarsh pools. It was shortly after 11 a.m. and the ice had melted at the edges of each pool but remained as a very thin layer over the rest. The angular patterns were not visible in the surface ice but were cast on the bottom of the pool by the sun shining through the ice. They were blurred by having to look at them through the surface ice but you can see them well enough. I wonder why an angle of around 60º is so frequent, something to do with six-sided crystals?
Didn't stop to count the birds at the estuary high-tide roost, but the above left picture shows a few of them. There were also some seals hauled out on a shallow bank a long way out from the water's edge (above right)
Up on the hill now, and this picture shows a rock where the Hooded Crows bring the shells from the beach to drop them from the air and crack them open. There were about 75% mussel shells and 25% dog whelks, did not find any other species. The place was over 40 m above sea level and there were others considerably higher.
I had a look round to see if I could ascertain whether some rocks are consistently favoured and other equally suitable ones ignored. This seemed to be so to some extent, but there were many intermediate sites with just a few shells. As there are plenty of rocks on the shore, presumably the hoodies bring the shells up into the hills in order to get away from other hoodies who would dive in as soon as the shell was cracked and snaffle the contents. In that case, it would defeat the purpose of the exercise to have traditional shell-cracking rocks, as other hoodies would get to know them, so I expect they just fly inland until there are no other birds in sight and then drop their shell on the first rock they see.
Even so, some of these rocks must have had a huge amount of calcium dumped on them over the centuries, and I wondered if this would ever be sufficient to give the soil around the rock an alkaline quality. There is no sign of this in the vegetation, so I guess it leaches away as quickly as the shells decompose.
You don't expect to see many caterpillars on moorland in February, but I found three. The first was this Ruby Tiger which insisted on remaining curled up despite every inducement to unroll. The second, later on, was similar but more active, and the third was a different species which we'll come to.
The above right picture is a close-up of the lichen Cladonia portentosa; thanks to Howard Fox for this id. This lichen is common on wet moorland and forms large cushions or balls. This one was growing around Deergrass and Cross-leaved Heath.
Had lunch overlooking the sandy beach in Camus Bàn. Didn't go down there as it was in shade and I wanted to soak up as much sun as possible after six weeks with virtually none. The bay must get very little sun in winter. There was a lone Oystercatcher on the sand, two Great Blackbacks close inshore together with a very mottled-backed seal swimming to and fro, and a bit further out 6 eiders, 3 male and 3 female.
Wondered at the significance of a single Oystercatcher on all that sand, when just round the corner there were dozens of them standing shoulder to shoulder on the spits of rock in the estuary. Is it just that the rich estuary mud can support 50-100 Oystercatchers for every one the sand can support, and so they naturally divide up that way? Or were the others a "flock" to which this solitary individual did not belong? They could be resident and this one a migrant passing through. Or vice versa. Perhaps this one had a mate and was occupying a breeding territory. As if in answer to this latest theory, another Oystercatcher flew across from the rocky part of Camus Bàn to join the first on the sand.
Here are a couple more lichens, from rocks that water seeps over.
They may both be the same species, in which case I think it's yet another Cladonia. The first has red cups with green balls in, and green squamules at the base, the whole thing in scattered patches on a black substrate which may be dead material from the same species or a different species. The second is a much neater affair, being a cushion of green squamules without cups or gaps. Tufts of moss are growing through the cushion.
Very few birds about on the uplands, but saw a pair of Stonechats, moving about between heather tufts, keeping close together. Both sexes always chose somewhere prominent to perch, obliging birds that they are.
At around 120 m the Fir Clubmoss (below left) started to appear, in among Deergrass and Heather in very wet peat. You can see the white spore-cases in the axils of the upper leaves. To me there's something unique about this plant in that it is virtually never found at or near sea level, yet it kicks in at a much lower height than the average montane species. If you're climbing a mountain your first sighting of this plant is a sign that you've come a good way but you've still got a long way to go.
One thing I'm determined to learn more about is tracks and signs of mammals, so I took photos and notes of the above "spraint", but I rather think it might be a bird pellet. Would welcome any enlightenment from those who know these things. The bulk of it was made up of matted white hairs. but there were also bits of bone, and white items which looked like feather shafts. The first picture is in situ and the second shows it turned over. At first I thought it was a mammal territory marker as it was placed in the middle of a bare rock, but I can't find any in my book that matches it, and the complete lack of any smell suggets a bird pellet.
Soon after this I put up a Red Grouse, the only bird I saw up there apart from the Stonechats, not couting any Hoodies which my memory will have filtered out.
Was surprised to find Sanicle growing in a rock crevice (below left), and Hard Shield Fern close by. Definitely worth a botanical visit in the summer. But winter is best for waterfalls...
Finally, this Drinker Moth caterpillar was on dead Purple Moor Grass, among Heather. They overwinter as caterpillars and appear in Spring to feed up until pupation in June.
Back to Penifiler, where there is a TV mast or something of the sort, and at the top a small circular structure where a dozen or so Starlings were roosting, all sitting around in a circle. Every so often one of them would do a brief flight a few yards out and back again. Dusk was about to begin. The sky was perfectly clear except for a small pink cloud above the Cuillin and a wispy white mantle on the back of the Storr. Scattered snow patches on the Cuillin, less than 10% cover.
By 6 pm it was halfway between day and night, and I was making my way back along the shore from the Varragill bridge towards Portree, the tide now out and the waders and gulls scattered over the mudflats. A mixed flock of over 100 Rooks and Jackdaws swung out over the water, the Jackdaws vociferous, the Rooks silent. It was getting increasingly difficult to see where I was putting my feet. By 6.38 pm six stars were visible, as well as one very bright planet. At intervals, moths fluttered across my path, out of the waterside vegetation and over the stony beach. They were all the same kind, a medium-sized species, all travelling from land to sea, never the reverse direction. As I reached the path that leads up to the road, some Curlews a little further along the shore, hearing my footsteps, began their bubbling chorus.