Kittiwake breeding distribution 2008-11 (Click to zoom)
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If you were asked to name our most abundant breeding gull species then I suspect that your answer wouldn’t be the Kittiwake. However, with some 380,000 breeding pairs, the Kittiwake is considerably more numerous than our other breeding gulls; in fact it is the most numerous gull species globally, with the United Kingdom holding about 8% of the World population. One possible reason for the Kittiwake not being an obvious answer to this question is that the species spends much of the year at sea, only venturing into our coastal waters during the breeding season, and it is rarely seen inland.

Sheer numbers

Kittiwakes breed on sea cliffs, so the vast majority of our colonies are to be found in the north and west of Britain and Ireland, where the sheer cliffs tower high above the sea. Perhaps a little surprisingly, Kittiwakes have also taken to nesting on some human-made structures along some North Sea coasts; the Newcastle-Gateshead quayside has been used as a breeding site for a number of years and there is even a colony on the BALTIC Centre for Contemporary Art, the birds nesting here being the furthest inland colony in the World.

The nest, which is typically placed on a narrow ledge, is a compact structure made of seaweed, mud and some grass. The material used in construction is trampled into shape and used to form a deep cup within which the clutch of two eggs (rarely 1 or 3) is laid. These are not the most hygienic of birds and the nest soon becomes soiled with droppings, becoming increasing white in colour and adding to the characteristic stench of a seabird colony.

Amber listing

Information on breeding numbers comes from the Seabird Monitoring Programme, coupled with periodic national seabird surveys. These show a decline in abundance over the last 30 years, with the Seabird Monitoring Programme index for 2014 being just 28% of that for 1986, when the programme started. The scale of this decline is one of the reasons for the Kittiwake being added to the amber list of birds of conservation concern.

The main factors in the decline appear to be linked to changes in the marine in environment, most notably changing prey abundance. Kittiwakes take sandeels and other small shoaling fish; energy-rich foods that are important for a productive breeding season. The start of the Kittiwake breeding season may be delayed by several weeks in those years when prey is scarce, and many pairs may not go on to make a breeding attempt at all. Productivity – the number of chicks produced per nest – has declined over time, though there is significant variation between breeding seasons, and by 2008 just a single chick was being produced, on average, from every four nests – this figure was closer to one chick per nest back in the late 1980s.

BTO-led research has revealed that some Kittiwake colonies have fared better than others, with western colonies significantly outperforming those on the east coasts of Scotland and England. A large sandeel fishery on Dogger Bank is within the foraging range of many colonies. In years when a greater proportion of the North Sea’s sandeels is fished, rates of breeding failure rise.

All at sea

The Kittiwake is the most oceanic gull and the individuals from our breeding colonies spend roughly half of the year at sea. The species is probably nomadic in its habits outside of the breeding season, wandering across large areas of the Atlantic Ocean, south to about 30°N (roughly the latitude where the Canary Islands sit). Ringing information shows that the movements of British and Irish-ringed birds have a strong westerly component; there are records, for example, of British Kittiwakes reaching Greenland within six weeks of leaving the nest. These young birds will remain at sea for several years and, while some youngsters may begin to visit breeding colonies from two years of age, some do not breed until six years of age.

Catching up with this small gull

In addition to the opportunities afforded by visiting the seabird colonies at which these small gulls breed, birdwatchers can also catch up with Kittiwakes when seawatching. Large numbers of Kittiwakes can be blown close inshore during gales and some may even be blown far inland, turning up at larger waterbodies.

Young Kittiwakes have a distinctive wing pattern, which helps identification, but some rare gulls look not dissimilar so it is worth brushing up on your identification skills with the BTO ID video for Kittiwake and other small gulls.

More BirdFacts for this species Seabird Monitoring Programme

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