Fauna of Port Gaverne Main, North Cornwall
(from unpublished surveys and observations by Malcolm Lee up to August 2001)
In common with the cliff ledges north and south of Port Gaverne Main, the ledges here are home to locally important colonies of Fulmars, Jackdaws, Rock Pipits, and Herring Gulls.
A colony of some 50 Feral/Rock Dove breed at Pigeon Gug. An ancient site this, as Pigeon Gug has been so called for over 150 years.
Stonechats and the summer visitor Common Whitethroat regularly breed in the scrub on the Main. Pheasants probably breed in the long grass, as their chicks are regularly seen in summer as they mature.
The following species on seen the Main in fair numbers each year, and probably breed there; Small Skipper, Large Skipper, Small White, Large White, Green-veined White, Common Blue, Small Copper, Speckled Wood, Small Tortoiseshell, Peacock, Meadow Brown, Wall Brown, Ringlet and Gatekeeper. These species are seen in small numbers; Orange Tip, Holly Blue and Comma, with singles of Brimstone seen passing through, but not every year.
During daily walks over the Main between 1992 and 2001, just a single fresh Marbled White was seen on 23rd July 1999. This was undoubtedly a male moving through, although the nearest colony of this normally sedentary species is over 5 miles away.
Migrant species naturally vary in numbers from year to year, but Red Admiral and Painted Lady are seen every year, sometimes in abundance, with Clouded Yellows seen most years in ones or twos.
The most significant butterfly on the Main is the Brown Argus. In North Cornwall, this is a very local butterfly, with just a handful of sites mainly around the Camel Estuary. Numbers of this double-brooded species are very low here, with single specimens only seen in any year. Although the last was seen on 28th August 1998, it is likely that it still survives at low density, and management efforts to improve the habitat for this butterfly would be worthwhile.
There are a great many moths living on Port Gaverne Main, most of which are nocturnal and rarely observed. Of the more noticeable are the hairy larvae of several common species of ‘Eggar’ moths which are frequently seen wandering in the grass; Oak Eggar, Fox Moth and The Drinker. The larval webs of another ‘Eggar’, the Lackey Moth, often festoon the Blackthorn scrub. The distinctive black, yellow and white larvae of the Magpie Moth are commonly noted on the Blackthorn scrub. Two day flying burnet moths are seen each year; the Six-spot Burnet, and the much less common Five-spot Burnet.
The Main does hold colonies of some uncommon moths, several of which are ‘Notable’ nationally. The very distinctive day flying Scarlet Tiger is nationally a very local species found mainly in the south west, and breeds here in good numbers on the damper sections of the slopes overlooking the beach.
The Thrift feeding Black-Banded is Notable A (recorded nationally in between 16 to 30 10km OS squares) and regularly turns up in September. Another Notable A is the grass feeding Devonshire Wainscot that has been recorded once on 16th August 1996, and may breed at low levels. The Notable B (recorded nationally in between 31 to 100 10km OS squares) species recorded are; the fern feeding tiny Japanese micro-moth Psychoides filicivora that can often be disturbed from Sea Spleenwort in the cutting near the footbridge, the day flying Thrift Clearwing feeds on Thrift and is noted on several occasions each year in the cuttings of the Old Slate Road, and the Pyralid moth Mecyna asinalis feeds on Wild Madder and is recorded most years, with the distinctive larval feeding patterns noted on many plants.
Other Notable moths have been recorded at lights in Port Gaverne less that 100 metres from the Main, and most likely breed on the clifflands; the micro-moths Argolamprotes micella, Oegoconia caradjai, and Mompha divisella, and macro-moths Ruddy Carpet, Hoary Footman, Crescent Dart, L-Album Wainscot, and Feathered Brindle. Records of the latter species form the only modern sightings for North Cornwall. The Pyralid moth Dolicharthria punctalis has been recorded in the grassland at Welshman’s Quarry, only a few hundred metres from here, and may be on the Main. The Small Yellow Underwing is a nationally declining species that has been recorded on single occasions in the grassland behind the Headlands Hotel, and near Grammer’s Chair, and may also breed on the Main.
(c) Other insects
The Main holds a big colony of one of our largest insects, the Great Green Bush-cricket. This is predominantly a coastal species and is quite local in North Cornwall. The Speckled Bush-cricket is also regularly recorded on bramble in the cutting near the footbridge. A surprising absentee from the local fauna is the Dark Bush-cricket, which is commonly found in association with the Great Green Bush-cricket in our coastal valleys. Our most common UK grasshoppers, Field Grasshopper and Meadow Grasshopper, are both abundant on the Main. The New Zealand phasmid the Unarmed Stick Insect is common in Port Gaverne and Port Isaac, and has occasionally been recorded on the Main.
There are many beetles, of which the Devil’s Coach Horse, the Leaf Beetles Oedemera nobilis and Oedemera lurida and Phaedon tumidulus, Cockchafer, Violet Ground Beetle, and 7-spot Ladybird are the most noticeable. There are old records for the Glow-worm in Port Gaverne, and the winged male Glow-worms have been recorded almost annually at my outside lights in recent years. Although the glowing females have not been seen on the Main, they may well survive in low densities. A single Green Tiger Beetle on 29th June 2000 was probably just a casual.
Of the wasps and bees, the pretty Ruby-tailed Wasp Chrysis rudii has been confirmed here by Mike Edwards. This is a local species predominantly found in the South West. Chris Haes has confirmed the presence of the uncommon Cuckoo Bee Psithyrus (now Bombus) rupestris, where it preys on the common Bumble Bee Bombus lapidarius, which it mimics. The latter bumble bee can often be the most numerous species recorded feeding on the flowers on the Main.
Reptiles and Amphibians
The Common Lizard and the Slow Worm are regularly found on the Main. The Adder is not uncommon in Port Gaverne, and probably could be found on the Main, although its habit means it is rarely seen. The Common Frog and Common Toad are both present.
The Weasel has been seen on the Main, and the distinctive earth hills made by the Mole are common. Field Voles are abundant in the grassy clifftops. Pygmy Shrew has been recorded, and may well be common.
A surprising omission is the Rabbit which has never been seen on the Main in the last 10 years of almost daily walking over it. Before the advent of myxomatosis in the 1950s, this mammal was excessively abundant in North Cornwall, forming a most significant local export on the North Cornwall Railway, with around a million animals sent up country each year to the meat markets of London and Birmingham. Old pictures of the Main show much finer grasses and very little scrub. In the absence of regular grazing by domestic animals (of which there is little evidence in the 20th century) it is likely that rabbits were the most important factor in maintaining fine cliff land swards. Whether re-introduction of rabbits would bring back the short turf, or be desirable, requires serious consideration.