Caithness Field Club

Caithness Field Club Bulletin
2004

Some Highlights of Natural History in 2003
by Mary Legg and Ken Butler

The importance of the Dunnet Bay dune system was highlighted this year after the Butterfly Conservation Society and Scottish Natural Heritage monitored the colony of small blue butterflies at Dunnet. This species is undergoing a steady decline and is a UK Species of Conservation Concern. However its status in the Highlands and Western Isles is elevated to high priority due to its rarity in the region.

All the sites along the north and NE coasts were visited at the end of June and the only one that appeared to be thriving is the one at Dunnet dunes. One matter for possible concern is that the dune system is eroding at the seaward side and it may be that some conservation work such as seeding or transplanting any eroded kidney vetch (the foodplant of the butterfly) be undertaken to maintain the colony.

The best time for seeing the small blue is June or contact the ranger service as they take guided walks in the area of the colony.

At the other end of the scale its been a good year for killer whale sightings. The first sighting was off shore from the castle of old Wick on the 5th May when a group of 6 were seen; again from the same place 12 were seen on the 25thMay. On the 16th of July there were sightings from Durness (2) to John O Groats (7). Ten days later a pod of 7 were seen off Stroma pier where they spilt into a group of 2 and 5. And the group of five were later seen between Gills bay and Skarfskerry early evening to Dusk. The animals included a large male. They were very active in the water and appeared to be rounding up fish (possibly salmon) very close to the shore. The last sighting was of Wick when three were seen.

A more unusual sighting was off a 50-60 foot whale in the Pentland Firth by St John`s point. It had a distinctive directly upright blow. Large white flippers which struck the waters` surface .It breached and landed on its side rolling as it re entered. The description fits the humpback and there have been increased sightings of this species off Britain.

The ranger service would welcome any sightings of cetaceans. And for anyone interested in Caithness and Sutherland wildlife we are running a wild encounters week again this year May 22nd -30th. Leaflets will be available in library and TIO.

The warm dry weather made it a good summer for plants. Over the winter several collected specimens were examined by experts. Lemna trisulca - ivy-leaved duckweed - was found in Loch of Winless by Dr NF Stewart. This is the only site north of Inverness and it is generally scarce in Scotland. Specimens were confirmed to be Fumaria purpurea - purple ramping fumitory - from a field at John o' Groats found there by John Crossley and Ken Butler. This is a scarce plant in Britain. Two specimens of orache taken from Caithness beaches were accepted by the expert to be Atriplex x tascheraui - a hybrid orache which may well be fairly common but is not easy to recognise in the large colonies of Babington's orache that colonise the beaches in September. A much rarer hybrid orache Atriplex glabriuscula x prostrata was found on Dunbeath shore by Ken Butler. The plant conservation charity Plantlife promoted a countrywide study of the wild hyacinth and the invading Spanish hyacinth. This led to the discovery of two colonies of the Spanish hyacinth in Caithness not previously recorded. And who planted a white Spanish hyacinth, a Solomon's seal and a Star-of-Bethlehem by the roadside at a lay-by on the road up to Dunnet Head?

A visit to the county by Dr Heather McHaffie of the Royal Botanic Gardens in Edinburgh produced a string of new records. Chaenorhinum minus - the small toadflax - was found on the railway track in the SW of the county. The Canadian waterweed Elodea canadensis was floating on St John's Loch and the tall ramping-fumitory Fumaria bastardii was found in a field at John o' Groats (yes - while looking for the other rare fumitory mentioned above). The west shore of St John's Loch was found to have a very large colony of the narrow smallreed Calamagrostis stricta (which is nationally very rare) and a very large colony of the hybrid horsetail Equisetum x litorale plus a small quantity of a hybrid horsetail that experts have not yet identified.

Ken Butler's ice house has a turf roof and for the first time he noticed the grass Trisetum flavescens growing in it. It is a common grass in England but scarcer in Scotland.

And as the first frosts of winter were arriving, Chris Ferreira noticed a plant from the south of England, Picris echioides - bristly oxtongue - bravely flowering on the banks of the River Thurso. It may have come from scattered birdseed which had prospered in our warm summer.