Ray Collier Country Diary - River Nairn

21st August 2007 -River Nairn

The source of the River Nairn lies in the hills above Dunmaglass a few miles south of Inverness. A number of burns tumble down the hillsides and eventually join to form the river whose upper parts flows through Strathnairn. Some of the river banks support alder trees and at one time they were very much in demand as the traditional wood for making clogs. The river also flows through conifer plantations, moorland, grassland and arable fields, the combination of which support a wide range of wildlife. In the summer sand martins breed in holes in banks that they excavate themselves but their numbers are limited. This is a spate river and unless the banks are high, which only happens in a few places, the nest holes would get washed out when the water rises. Grey wagtails, considered by some to be one of the more attractive birds in the Highlands, build their neatly cupped nests in crevices high in a bank. The common sandpiper forms a cup in grassland close to the bank and relies on its camouflage to outwit predators such as crows, foxes and pine martens.
These birds are moving south at this time of the year but there are still plenty of birds to see during the coming months. The most obvious water bird is the dipper, sometimes still called the water ouzel. These are one of the few birds that sing nearly all the year round and its sweet rippling warble can be heard in most months including the autumn and winter. Their sharp call notes can be heard above the noise of the river. Their territory may be up two kilometres long and will be maintained for the winter months unless the river freezes over. In such conditions the birds move to the coasts of the firths around Inverness but they return as soon as conditions allow. Flocks of small birds flitting amongst the branches of alder trees are likely to be lesser redpolls feeding on the alder seeds. Flocks of these attractive birds used to be commonplace in the Highlands but since the early 1970s there has been an overall decline of 90% and nobody seems to know why.
This is a good time of the year to see the very elusive otter as although the days are getting shorter there is less cover along the banks. Many books say that the otter is entirely nocturnal but in areas where they are not disturbed they can be seen feeding during the day. The best approach is to find out if otters are present and this is easily done by looking for their tracks or their droppings. Any stretch of the River Nairn is good for tracking especially where there are ox-bows where the water course turns back on itself. When the otter is moving along the river it often cuts across these oxbows so leaving tracks in mud or sand. The tracks show five toed webbed feet about 60 mm in length and about as wide as they are long. The droppings, called spraints, are dark and slimy with a strong fishy smell and fish scales and bone fragments may be visible. Otter holts, or dens, and lying up places called hovers are often under river side tree roots and the fact that alder trees often have their roots showing means they are favourite places on the River Nairn. The best time to otter watch is at first light and at dusk but if you are lucky you may see one during the day.

Ray Collier Highland Country Diary - Brook Lampreyl

Brook Lamprey 13th August 2007

The brook lamprey, found in many parts of the Highlands, has one of the most extraordinary life cycles and one that means that we very rarely see them. They are the most primitive of living animals and are related to fish although there are characteristic differences between them. The brook lamprey has no jaws like other fish but instead there is a round sucker like disc within which there are many strong, horny, rasping teeth. The adults are eel shaped but have neither paired fins or scales. They have no bones and all the skeletal structure is made up of strong, but flexible, cartilage. They have only one nostril, situated on top of the head just in front of the eyes but the eyes are rarely functional and are not visible in the young. The gills open directly to each side of the head and form a row of seven gill pores behind each eye. Adult lampreys have two dorsal fins which are often continuous with the elongated tail fin and they only grow up to 17 cm. The young lampreys are worm like, grey brown and they are blind.
If the structure of lampreys seems extraordinary then so is their life style. The juveniles, called prides, immerse themselves in silt and filter fine organic particles and they remain there for up to six years. Then in the autumn they change into adults but still buried in silt and if by any chance they are disturbed they swim around rapidly until they find suitable silt and then they bury themselves in seconds. Then they emerge around May to mate and spawn. As adults they do not feed and as soon as the eggs are laid they all die. The nest in which the eggs are laid is normally an oval depression in gravel up to 40 cm across and 10 cm deep. Each female produces around 1,500 eggs and as soon as they hatch the young larvae leave the nest and spread out by drifting downstream and eventually burrowing into suitable areas of silty sand. Then the lengthy life of the young ones and short life of the adults starts again. Brook lampreys are scattered throughout the Highlands although at one time they were not thought to occur north of the Great Glen. Recent records refuted this claim and this was one of the reasons for current surveys which have indicated they are more widespread than previous records suggested. The resulting, revised distribution maps should be out shortly.
When the brook lampreys gather to mate they simply throw caution to the winds and for a short time the seething mass of activity regularly attracts predators such as gulls, larger waders such as curlew, herons and ducks such as mergansers. Predatory mammals include otter and mink. Because of their life style and comparatively small size, brook lampreys, unlike their close cousins, river and sea lampreys, have not been caught commercially. The best chance of seeing a brook lamprey around Inverness is to look along the banks of rivers and burns in late summer to find dead specimens. These lampreys are numerous on Loch Ness, the River Findhorn and River Nairn and all their contributories. In some areas, for some unknown reason, the adult brook lampreys are much smaller than in others and one such area is on Skye where they have been seen spawning in small burns with the adults only 10 cm long. The photograph was taken of a dead fish found on the banks of the River Farnack a few miles south of Inverness and the seven gill openings behind the eye can be seen.

Ray Collier Highland Country Diary - Bog Asphodel

Bog Asphodel - 7th August 2007

The long, slender, often curved leaves rising from the bottom of the bog asphodel surround the upright and leafy stems. This is topped by a dense spike of up to 20 flowers with whorls of narrow yellow lobes, sometimes 15mm across and with orange stamens. The plant is often so numerous that it can dominate the bogs and marshes where, as the name suggests, it grows. Various books describe the flowers as yellow, golden yellow and yellow orange. Although there isn’t, in fact, much colour variation between plants, this member of the lily family changes it colour in late summer. After flowering, the whole plant turns to a deep orange colour, described by some as dark saffron. In large numbers this can be just as dominating as the yellow flush of the plant in summer. At one time it was regarded as a true miniature asphodel, a lily of the field with a different Latin name. Despite its preference for wet conditions the bog asphodel is surprisingly widespread over the whole of the mainland of the Highlands plus the Western and Northern Isles. Ursula Duncan in her book "Flora of East Ross-shire" describes the plant as very common and mentions a number of sites. She then goes on to say that it grows "wherever there is wet peat from near the mountain summits down to the coast". The plant has, in fact, been found flowering at altitudes above 3,000 feet. It can grow, and dominate, the widest tracts of wet moorland to the smallest wet areas on the side of the road. However, it must have been adversely affected by the great conifer plantations of the flow country as it is intolerant of shade. Although bog asphodel is slightly toxic, in many upland areas it is still heavily grazed. The second part of the plant’s Latin name is "ossifragum" which means "bone-breaking". It was given this name because it was thought that the plant caused brittleness of the bones of sheep that ate it. This is now known to be untrue as the bone problem is the result of grazing sour, calcium poor areas. In the past women collected the plants from the moorland and used them to dye their hair yellow, hence the local name of "maiden hair". It is also said to have been used in Shetland as a substitute for saffron which is normally obtained from a Mediterranean crocus. Unusually, for such a striking and widespread plant, no clan seems to have used it as a plant badge. The Gaelic name is "bliochan" meaning "milk plant" from "bliochd" meaning milk, but the reason for this name is obscure. Another local name is "cruppany grass", again from the mistaken belief that it gave sheep "cruppency" or bone stiffness. Because of it abundance the future of the bog asphodel seems assured, despite the worry in the past of drainage and the once lucrative practice of planting up with trees for the tax grants. The conversion of large tracts of the coniferised "flow country" to treeless areas and reversion to wet moorland and associated bog pools means that the plant may be restored to its former glory. Despite the huge tracts of wetland in the Highlands there is still evidence of local development and drainage causing problems to wetland plants in general. At one time any wetland area was seen as potential conifer or alder planting sites but at last common sense seems to have prevailed.