Black-headed Gull Larus ridibundus
- IdentificationVisual tips about this species
- BehaviourHabitat, behaviour, and food
- PopulationSubspecies and numbers
- ReproductionNesting and eggs
Identification
Novice birdwatchers are often perplexed when they see gulls in winter with mostly white heads which are called Black-headed Gulls, then even more puzzled when you explain that in summer the heads actually become brown, although they often look black from a distance. In summer plumage, the dark hood only just covers the face and doesn't go down the nape as in the other dark-headed gulls. In winter plumage you have to look carefully at the distribution of black on the head and compare it with the dark eye-mask of a Mediterranean Gull and the sooty skull-cap of a Little Gull. Black-headed Gulls in all plumages have a white forewing, making a triangular white panel in the leading edge of the primaries.
Ageing
A two year gull. First winters differ from juveniles in their greyer mantle and generally less brown plumage. First summer birds are similar, but with a partial brown hood. After moulting in August-October they then look like adults.
Voice
Black-headed Gulls have a grating 'grak grak' call, which is often given.
Sexing
Sexes similar.
Length
38cm
Behaviour
The dark hood which develops in summer is a symbol of aggression, so that two competing males will face each other to show as much of the hood as possible. However, to reduce aggression between members of the same pair, they have developed ritualistic displays in which the head is suddenly turned away so the partner only sees the white of the back of the neck.
Migration
Except in Ireland where there is only a little dispersal, most European birds migrate to the south or south-west for the winter.
Habitat
Breeds on coastal and inland marshes, moorland and gravel pits. Winters on estuaries, lakes, reservoirs, coasts and rubbish tips.
Food
Fish, insects, worms, carrion, refuse and marine invertebrates.
Population trends
There has been a marked increase in western Europe, particularly in the last century due to protection and possibly climatic change enabling these birds to spread northwards and westwards. They reached Iceland in 1911 and Spain in 1960. In Sweden it was a rare breeding bird at the turn of the century but by 1970 there were over 270,000 pairs. However, here, as in several other parts of Europe, numbers have since fallen by about 20%. They are susceptible to changes in weather conditions; too little rainfall can reduce the availability of food, too much can flood out the breeding sites.
Subspecies
Monotypic.
Population in Britain and Ireland
167000 breeding pairs in Britain, a further 53 800 in Ireland. This is one of the most 'inland' of the gulls, often seen far from the coast. Winter figures are probably in excess of 1900000 birds.
Where in Britain and Ireland
The commonest British gull, found virtually everywhere.
Population in Europe
About 2 million pairs in Europe
Where in Europe
Widespread and common in many parts of Europe.
Nests
Colonial. Builds nest on ground using a wide range of plant material.
Eggs
3, buffy, with black spots, laid in April to May. Incubation takes 21-27 days. Young fledge after around 35 days. 1 brood per year.
Powered by