Kittiwake

The kittiwake is a member of the gull family that is generally only seen during the breeding season. It spends the winter far out to sea.

Distribution

European kittiwakes spend much of their life at sea, far from land in the mid-Atlantic or the North Sea. During the breeding season they can be found along the coasts of Norway, Iceland and the British Isles. They do not venture inland, although nesting birds will sometimes use fresh water near the shore for bathing.

Appearance

The kittiwake (Rissa tridactyla) is similar in size and appearance to the common gull, but slighter, slimmer, and with black legs instead of yellow. It also has a smaller head and can be distinguished in flight by its black wingtips, which give the impression that the wings have been dipped in ink.

The kittiwake is around 40 centimetres (16 inches) long. The head, chest and underparts are white and the back and wings grey, apart from the wingtips mentioned above. The bill is small and yellow, and the eyes black with orange-red rings. Males and females have similar plumage.

Behaviour and feeding

In flight, the kittiwake beats its wings rapidly. Lines of kittiwakes can be seen over the sea, feeding from the surface. They will also dive from a settled position, or plunge in a similar way to terns.

The bird takes its name from its call, a rhythmic “kitti-week” that is heard when nesting. A recording of the call, plus a lot more information, is available on this page of the RSPB website.

Kittiwakes feed on fish and marine invertebrates such as crustaceans and molluscs. Sand eels are a regular food, and kittiwake numbers in Great Britain fluctuate depending on the availability of this food source. At present they have amber conservation status for this reason, which is possibly the result of climate change.

Breeding

Kittiwakes breed in colonies, which they reach any time from February and stay until August. These are mainly ledges on steep cliffs, but in some places, such as Norwegian fishing ports, they have also taken to nesting on the ledges of artificial cliffs, namely tall buildings.

The nest is quite a sturdy structure, constructed by both partners from plant matter such as seaweed, moss and lichen, held together with mud or clay. The eggs, usually two but sometimes three, are laid in a hollow dug into the top of the nest mound. Laying takes place in May or June and both birds incubate in turn, for up to 24 days. Kittiwakes are unusual among gulls in that the chicks stay in the nest until they are ready to fly, which can be as long as 36 days, being fed by the parent birds for the whole of this time.

When all the chicks have fledged, the whole colony will leave for the open sea, with only one brood being raised per season.

 © John Welford