NORTH WALES WILDLIFE TRUST

Rhiwledyn Nature Reserve

Rhiwledyn nature reserve forms part of a limestone outcrop that extends from Anglesey along the North Wales coast and south to Llangollen and covers 12 acres of land on the Little Orme headland. It covers a number of diverse habitats including limestone grassland, unimproved meadow, scrub-covered slopes, cliffs and bare rock areas.

Limestone Grassland

The grassland areas of the reserve have been grazed by sheep and rabbits for many years. Grazing removes nitrogen and allows the growth of fine leaved grasses and low growing plants, which would normally be out-competed by coarse grasses or scrub. Too much or too little grazing is harmful. Recent European and HLF money has enabled the site to be stock-proofed, giving NWWT control over the sheep grazing.

The reserve is botanically rich, with examples of plants typical of both calcareous grassland and coastal habitats. Calcareous grassland plants found on the reserve include Quaking Grass (Briza media), Dropwort (Filipendula vulgaris), Carline Thistle (Carlina vulgaris), Bloody Cranesbill (Geranium sanguineum), Kidney Vetch (Anthyllis vulneraria), Ploughman’s Spikenard (Inula conyza), Yellow-wort (Blackstonia perfoliata), Spiked Speedwell (Veronica spicata) and White Horehound (Marrubium vulgare). Plants more typical of coastal grassland include Wild Cabbage (Brassica oleracea) and the nationally uncommon Hoary Rockrose (Helianthemum canum).

Unimproved Meadow

The small meadow is bounded by remains of stone walls which were probably made from stones cleared from the field. Heavy grazing by sheep and rabbits has resulted in patches of bare soil and short grass dominated by Ground Ivy (Glechoma hedera). This area is exposed to strong, salt laden winds which slow the spread of Blackthorn scrub. There are several anthills of the Yellow Meadow Ant (Lasius flavus) in this area, showing that the meadow has not been cultivated for some time.

Scrub-covered Slopes

This area is covered with a fairly dense growth of Blackthorn, with some Sycamore, Elder, Holly, Juniper and Wild Privet. Wild Clematis (Old Man’s Beard) climbs the trees and nettles grow in the dense shade. Birds find this an attractive, sheltered nesting and feeding place.

Cliffs, Bare Rock

Here Fulmar nest on ledges and the Rock-Rose (Helianthemum chamaecistan) adorns the cliff face. The inaccessibility of these areas of the reserve allow for an undisturbed habitat.

Invertebrates

There is a wide range of invertebrates on the reserve. The calcareous soil is especially good for snails which require calcium to produce their shells. The most common snails are the Brown-lipped Snail (Cepaea nemoralis) and the Garlic Glass Snail (Oxychilus alliarius). Unless conditions are damp, snails are best found in the clefts in the limestone, where they are hidden from predators and the sun. Butterflies such as Speckled Wood, Peacock, Gatekeeper, Meadow Brown, Grayling and various moth species may be seen on the reserve. Butterflies and moths are often associated with specific plants. The variety of plants found on the reserve support the food needs of the adults and larvae (caterpillars) of many species.

Birds

Birds can be seen throughout the reserve. Coastal birds, such as Fulmars, nest on the rocky cliffs within the reserve. These compact birds have long narrow wings adapted for gliding and are most easily identifi ed by their tube noses and stiff-winged flight. Fulmars have the ability to spit foul smelling oil at intruders. During the breeding season Cormorants, nesting on the nearby sea-cliffs, collect nesting material from the reserve. Ravens and Jackdaws can be seen on the rocky outcrops and cliffs. Within the scrub Wrens, Blue Tits, Great Tits, Thrushes and Blackbirds abound. The patchy Gorse on the limestone grassland provides protection and nesting sites for Linnets and Goldfinches. Buzzards, Sparrowhawks and Kestrels can often be seen hunting over the reserve. Sparrowhawks and Kestrels are most often seen at the foot of the reserve, within the scrub. Female Sparrowhawks, which are about a third bigger than the males, eat medium sized birds such as Blackbirds or Thrushes. The males eat smaller birds such as Sparrows, Blue Tits and Wrens. The difference in diet between the sexes prevents competition and enables a pair to hunt over a smaller territory.

Mammals

As well as Rabbits, which play an important role in grazing the site, the reserve supports Bank Voles and Stoats. Bank Voles are shy and timid and feed upon shoots, berries and seeds. Stoats hunt for Rabbits, Voles and young birds.