Features

Coastal Wildlife Communities

The seaside in summer provides magical stimulation for all the senses writes Martin Brennan.

Summer is here and the landscape is once again clothed in fresh new greenery. Flowering plants add colour and fragrance, most noticeably hawthorn decorating the countryside with ribbons of white along almost every roadside and hedgerow, to be replaced by the cream-coloured flowers of elder as the hawthorn blossom fades towards the end of May. Carpets of bluebells and wild garlic brighten broadleaved woodland. Insects are busy adding to the hum, colour, spectacle and movement of the summer season, and birdsong, at its peak in early May, brings joy to our wakening hours.

Crowded colonies

In addition to all that, some truly spectacular wildlife sights are put on display at this time of year, the most impressive being that of the breeding seabird colonies on cliffs and islands around the coast. The birds come ashore and congregate in huge numbers to nest and rear young, with the greatest concentration of activity occurring in May. Forming mixed colonies each species has its own requirements relating to physical characteristics and location on the varied cliff structures, with row upon row of birds completely covering them and utilizing every available space. Nesting techniques vary also.

The middle and upper parts of the cliffs are occupied by Guillemots, almost defying gravity as they nest on narrow ledges. Like the related Razorbill (both auks), they do not build a nest but lay their single eggs directly onto the bare rock. This most exposed space is shared with Kittiwakes, a gull-like bird with distinctive black legs and bright yellow bill. They however, cement their perilously positioned nests of vegetable matter to the cliff with guano (excrement), and usually lay two eggs. Eggs of cliff nesting birds are generally elliptical in shape, particularly that of the Guillemot, which is described as pyriform - very narrow or pointed at one end so that it rotates in a tight circle and does not roll off the ledge.

Varied nesting sites

Sheltered ledges lower down are colonized by Razorbills. With black upper, and white lower plumage it is similar in appearance to the Guillemot, but has a laterally flattened bill with vertical white lines, compared to the pointed black bill of the latter.

Shags, large birds, similar in appearance to Cormorants, but with stunning green eyes and a glossy green sheen to its dark brown plumage, also select more sheltered positions at this level. Building a nest of seaweed and other plant material, it has a larger clutch of 3 to 4 eggs.

Fulmars and Gannets are most typical of the upper slopes, with the latter spreading out over the top. Fulmars, somewhat gull-like, have a very distinctive tubular nose through which nasal glands secrete excess salt. It constantly patrols the cliffs in a figure of eight flight pattern, and uses only a minimum of nest material, if any, for its single egg.

Gannets are the largest and most impressive of these sea birds. They have white plumage with black wing tips, a large delicately painted pale blue beak, with grey eyes and heads washed with cream. Unusually among birds, both eyes face forward enhancing the bird's expertise when hunting for fish which are caught in a most spectacular dive. The wings are folded back and like an arrow it plunges headlong into the sea, often from an height and at speed. Hunting in large numbers they provide a deadly show of skill and accuracy in rough marine waters. They build substantial nests for a single egg, and have elaborate courtship and greeting ceremonies providing endless interesting behavioural displays.

Puffins the most colourful of the auks with their characteristic, parrot-like, multi-coloured bills nest in underground burrows akin to rabbit warrens. Storm Petrels and Shearwaters likewise burrow into grassy banks to lay their eggs and rear their young hidden from public gaze. These latter two remain at sea during the day, returning to feed their young at night, crooning and crowing in an effort to locate their mates on the nest. Both, like the aforementioned Fulmar are tube-nosed.

Tower of Babel

Coastal habitats and islands, where human disturbance is at a minimum, may support a range of other ground nesting bird species, either in colonies or individually. Terns, gulls, plovers and some waders are typical, making walking an exciting experience, but requiring the careful placing of footsteps an imperative. Plovers attempt to divert attention from their nests by feigning injury, but terns are more aggressive, attacking and dive-bombing human intruders. In addition the glossy black Chough with its curved red bill and red legs can be seen searching for food in well-grazed grassland.

It is not just the spectacle of such vast numbers of birds which creates the impact, but their colour and variety, the constant cacophony of sound and commotion, the displays of visual and vocal communication, the fighting, bickering and stealing, competition for limited space, the tender care of young, the overall display of animal societal behaviour, and the interaction between individual birds and their neighbouring species. The air is a blur of birds performing aerial displays in the updraughts.

Stimulating environment

There is the added beauty and character which the marine environment contributes, with the constant soothing rhythmic background sound of the ocean and wave action. There is the blue sea and sparkling water (on a good day), the vast open skies and the intensity of reflected light ensuing. There is the colour and texture of the rocks, some coated by bright orange, among a range of other coloured lichens, adding to the rich pattern. Then there is the unique coastal flora, which has adapted to this harsh and inhospitable environment. Cushions of thrift add bright splashes of pink as they colonise suitable ground on cliff top and sides, and sea campions introduce carpets of white adding to the mosaic. There is the salty taste of the ocean carried on the wind, and the unique smell, a potent mix of the ocean, sea weed, terrestrial vegetation and the bird colonies themselves, all adding to the intoxicating effect. It is a most exhilarating experience which, I believe can be attributed to the fact that there is stimulation for all five senses as one clambers about.

It is this confluence of marine and terrestrial environments and the ensuing physical features which make these areas unique, providing niches for a rich diversity of wildlife influenced by the coastal climate and associated conditions - salinity, humidity and temperature. The ecology and character of a range of habitats - cliffs, caves, salt marshes, mud flats, dunes and grassland including machairs - are a consequence of the features, circumstances and conditions where land and sea meet.

Life on the shoreline

The pace and nature of life on the rocky shore and associated pools is dictated by the daily tidal flows. Sea anemones, just a soft jelly-like mass when the tide is out are transformed on its return to appear almost flower-like with their many delicate tentacles waving about in search of food. This beauty is deceptive. Anemones are effective carnivores feeding on zooplankton, and some even on crustaceans and small fishes. The tentacles are stimulated by the touch of potential prey, which they trap and inject with venom to subdue and digest it. Other creatures include starfish, whelks, crabs and small fish. Tiny barnacles cover the rocks and operate in a somewhat similar way to the anemone. Plates on the shell form a trap door through which its modified legs are extended when the tide is in, to catch food which is passed to the mouth. Limpets cling tightly to the rocks when the tide is out, often in a depression which they have created, and into which they neatly fit. At high tide they move about grazing algae on the rocks. There is also the diversity in texture, shade, shape and form of the varied sea weeds waving in the water, and providing cover and food for a range of creatures.

There is so much more to impress and fascinate, but these are the most visible and impressive facets of the intricate and interdependent ecological systems to be found around the coast in early summer. The coastline and offshore islands are magical places where animal communities, specifically birds, display communal living at its most concentrated, with a beauty and intensity capable of stimulating the full range of human senses making for a most exhilarating experience.

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