DESCRIPTION:
Herring Gull is a large gull, very common in coastal areas.
Adult in breeding plumage has pale grey upperwing and mantle, with some variations of grey. Wings are black-tipped with white-spotted pattern.
Underparts and tail are pure white.
Head is white with powerful yellow bill. We can see a red spot on the lower mandible. Eyes are pale yellow with orange eye-ring. Legs and feet are pink.
Adult in winter plumage has dusky streaks on head and neck. The bill is duller yellow with narrow black ring.
Both sexes are similar in plumage, but male is larger than female.
Juvenile has grey-brown with white spots plumage. Primaries and tail feathers are blackish.
It reaches the adult plumage at about 4-5 years.
SUBSPECIES:
We find four subspecies:
L.a. smithsonianus, from North America.
L.a. argenteus, from Iceland, Faeroes, British islands, West France to West Germany.
L.a. argentatus, from Denmark, Fenno-Scandinavia to Kola Peninsula.
L.a. vegae, from North-east Siberia.
HABITAT:
Herring Gull frequents mainly coastal and near-coastal areas. It may be seen inland at large lakes, in fields and at rubbish dumps.
This species breeds on islands, sea cliffs, marshes, sandy dunes and buildings.
It frequents a wide variety of areas such as estuaries, bays, harbours and farmlands. It roosts mainly on islands or coastal and inland lakes. It adapts to inland cities little by little.
RANGE:
Herring Gull is very common and widespread along the coasts of Asia, West Europe and North America.
The birds of the northernmost parts of the range and colder areas migrate southwards in winter.
BEHAVIOUR:
Herring Gull is highly opportunistic, taking advantage of abundant food resources is available. It is a powerful predator.
It feeds on numerous marine invertebrates, but also molluscs, worms and crabs on tidal flats.
It often scavenges at rubbish dumps and follows the fishing boats.
Herring Gull is a predator of birds, eggs and young, but it also takes rodents, insects and consumes berries when inland.
It feeds by walking along mudflats, plunge-diving and surface-dipping, as other gull’s species. It drops bivalves on hard surface in order to break open the shells. It also steals food from other seabirds.
Herring Gull is very gregarious, living and nesting in colonies. Outside breeding season, they rest, forage and roost in groups. But each gull has its own territory and maintains a safe distance from the other birds. Fighting may occur between close neighbours.
FLIGHT:
Herring Gull has great mastery of the air and flies easily thanks to the large wings.
REPRODUCTION:
Breeding season occurs from May to June.
Herring Gull gathers in large colonies for nesting, rarely solitary or at the edge of other seabird colony. In some colonies, the density is very heavy, and aggression and cannibalism are increasing.
The nest is built by both mates on the ground, sheltered by rocks or vegetation. It is a shallow depression lined with soft materials such as grass, feathers and varied items such as plastic, paper… The bulky nest may be located on cliff ledge or locally on roofs.
Female usually lays 2-3 eggs. Incubation lasts about 28-30 days, shared by both parents.
At hatching, chicks are covered with cryptic greyish and brownish down. They are fed by regurgitation by both adults. They leave the nest very soon, but they fledge about 40-45 days after hatching, and become independent 10 to 15 days later.
This species produces one brood per year.
DIET:
Herring Gull feeds on marine invertebrates such as fish, crabs, molluscs, worms, mussels and numerous bivalves. It is often found at rubbish dumps inland, and it also takes rodents, birds, eggs and young, insects and berries.
PROTECTION / THREATS / STATUS:
Herring Gull is one of the most abundant species in the range. Populations have increased strongly, thanks to protection from persecution and egging.
But the Herring Gull is regarded as pest and threat to many colonial species.
However, populations expanded greatly in the 20th century.
Sources :
HANDBOOK OF THE BIRDS OF THE WORLD Volume 3 by Josep del Hoyo-Andrew Elliott-Jordi Sargatal – Lynx Edicions – ISBN : 8487334202
THE COMPLETE BOOK OF BRITISH BIRDS – Written by “Royal Society for the Protection of Birds” experts – Préface de Magnus Magnusson – Michael Cady- Rob Hume Editors – ISBN: 0749509112
THE HANDBOOK OF BIRD IDENTIFICATION FOR EUROPE AND THE WESTERN PALEARCTIC by Mark Beaman, Steve Madge – C.Helm – ISBN: 0713639601