Seabird Cities

Seabird cities present an opportunity for the study of a large number of birds that nest together in crowded colonies but with little competition between the different species. This factsheet gives brief details of the birds’ life histories.

Colonies provide safety and they are usually close to a good food supply. Other sea birds which breed in colonies can also be studied. Some interesting examples are many shearwaters, storm petrels, gannets, terns and gulls. A cross section through a cliff could make an interesting classroom display together with a map showing where the birds breed on our coast and where they move to in winter. It is hoped that these few suggestions and the factsheet will help you in your study of seabird cities.

Puffin: (Fratercula arctica)

Size: 30cm (20 cm high).
Food: Mainly sand eels, sprats – can hold up to 11 fish crosswise in its beak
Breeding: Single egg laid early May onwards. Nests in burrows. Egg is incubated for 6 weeks, by both parents. Chick is fed 6 – 9 times a day. After 40 days feeding stops and about 10 days later the chick will leave the nest.
Threats: Pollution and overfishing by man.
Decreasing in numbers.


        

Razorbill: (Alca torda)

Member of the Auk family.
Size: 41cm (25 cm high).
Food: Crustaceans and fish caught underwater. Dive to a depth of 7 metres, staying submerged for up to a minute – underwater they only use their wings.
Breeding: Single egg laid early may onwards. Nests in large crevices. Egg is incubated for 4 weeks by both parents. When the chick is two weeks old the parents encourage it to flutter down to the water, where the parents feed it for several more weeks.
Threats: Oil pollution and overfishing by man.
Decreasing in numbers.

 
        

Common Guillemot: (Uria aalge)

Size: 42cm (25 cm high)
Food: Mainly sprats, also crustaceans, worms and molluscs.
Breeding: Single pear shaped egg laid in late May. Nests on bare cliffs. Parents share incubation for 4 weeks and like the razorbill is enticed to the sea where both parents feed it for a time.
Threats: Oil pollution and overfishing by man.
Decreasing in numbers, particularly in the south of England.

 
        




Kittiwake: (Rissa tridactyla)

Size: 41 cm high
Description: Distinguished by a neat black triangle on the tip of its wing. Short three-toed feet are black, its beak yellow.
Call is onomatopoeic kitti-w-a-ak.
Food: Sprats mainly – they pick off the ocean in flight.
Breeding: breeding begins at 3 years. Bracket type nest made of green seaweed, excrement, mud and a final cup made of grass.
Two eggs, incubated by both parents for 26-28 days.
Chicks are fed for 40-45 days.
Threats: Overfishing by man.

 
        

Shag: (Phalacrocorax aristotelis)

Size: 76 cm.
Description: In spring has a tufted crest. Ark, glossy, green sheen to the coat.
Breeding: Nest is built of seaweed, sticks and debris. 3 pale blue eggs laid in April, incubated for four weeks. The chicks are brooded for two weeks. Fed on regurgitated food. At 6-7 weeks they leave the nest but are still fed at sea for a few more weeks.
Threats: Overfishing by man may be affecting numbers as with other seabirds, also oil pollution.

 
        

Cormorant: (Phalacrocorax carbo)

Size: 90 cm.
Description: Larger and blacker than the shag. White thigh patch in breeding season.
Food: Mainly fish.
Breeding; the male collects the nest building material and the female arranges it. 3-5 eggs are laid, incubation shared by parents for four weeks. Like the shag they are fed on regurgitated food. At 7-8 weeks they start to learn to fly, staying with their parents a few more weeks.
Threats: possibly overfishing and oil pollution.

 
        

Fulmar: (Fulmarus glacialis)

The name means ‘foul gull’ as it is able to eject rancid oil from its stomach for a distance
of about one metre when threatened at the nest!
Size: 47 cm.
Description: Looks like a stiff winged herring gull, shorter neck and stouter head.
Food: Mainly fish.
Breeding: Nest is situated on a broad, well vegetated ledge. One egg is laid, incubated by both parents for 41-57 days. Fed on regurgitated food and fledges at about 7 weeks.
Threat: Possibly overfishing by man.

 
 
Information supplied by the Young Peoples Trust for the Environment