Chroicocephalus ridibundus

Black-headed gulls are not fussy eaters. They like everything, from worms to bird eggs to fish. Furthermore, they also profit from all kinds of human sources of rubbish such as garbage barrels. Not all black-headed gulls earn their meal in an honest way. They steal worms from shorebirds and fish from terns. Nor are people always safe. Should your ice cream or french fries fall on the ground, it quickly disappears in the beak of these master thieves. You find black-headed gulls almost everywhere. They are a common shorebird, land-bird and city-bird.

These gregarious birds are usually seen in flocks or small groups (3). They feed on worms, other soil invertebrates, scraps, rubbish, carrion and fish (3) (5). During winter, black-headed gulls roost on open water, typically fresh water, although they may occasionally make use of sheltered estuaries (5). These gulls nest in colonies, within which pairs defend small territories. They will defend these territories from other birds using ritualised displays (7). Two to three eggs are produced which are incubated for up to 26 days. After a further 35 days the chicks will have fledged (3). Black-headed gulls are fairly long lived, with a maximum recorded life-span of 32 years (3).

The common name of this species is inaccurate, as adult black-headed gulls have a chocolate-brown head in summer (5). In winter, this brown hood retreats and the birds have a largely white head with a dark spot behind the eye (5). Other distinguishing features include the prominent white leading edge of the upper wing, which is visible from a fair distance, the tern-like slender wings and the reddish coloured bill and legs (2). Juveniles are different in appearance to adults; they have ginger-brown coloured upperparts and a yellowish bill with a black tip (2). This is a noisy species during the breeding season, producing a loud kwarr call and a short kwup (6).

N Palearctic; winters to Africa, s Asia and e North America.

Belgian Coast, Belgian Exclusive Economic Zone, De Panne, Djibouti, Eritrea, Eurasia, European waters (ERMS scope), Gulf of Maine, Kenya, Mozambique, North West Atlantic, Polish Exclusive Economic Zone, Portuguese Exclusive Economic Zone, Red Sea, Somalia, Spanish Exclusive Economic Zone, Tanzania, United Kingdom Exclusive Economic Zone, Wimereux

North America; Labrador to North Carolina

The Black-headed Gull breeds in north-east North America and across much of Europe and Asia, excluding the north of each continent (northern Scandinavia and north Russia), and south Asia. Some populations in North America and the milder areas of Europe are resident, with the remaining populations wintering to the south over a large range, encompassing much of the southern coast of Asia and Europe, and the central and northern coast of Africa¹.

The breeding range of Larus ridibundus is very broad, extending from the southern tip of Greenland and all of Iceland down through the majority of Europe and Central Asia. The Kamchatka Peninsula forms this species' eastern range; Ussuriland in Russia and Heilongjiang in northeast China lie at the extreme southeastern part of this range. Larus ridibundus is uncommon in northeastern North America.

The northern population of this species is migratory. Birds residing at lower latitudes, however, tend to be non-migratory. Most birds in the western Palearctic breed in central and north European wetlands and migrate to their winter grounds in the Mediterranean basin. Birds that breed in Scandinavia migrate to the Brittish Isles, and the majority migrate farther, flying along the Atlantic Coast to West Africa. Birds from Central Asia migrate south to India, Malaysia, and Philippines. North Africa, particularly Egypt, is a common destination for L. ridibundus (Howard and Moore, 1991; Cantos et al., 1994).

Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Non-breeding

Global Range: BREEDING: Iceland, Faroe Islands, Eurasia, southeastern Canada, northeastern U.S. European population expanded northward since the mid-1800s, probably due to amelioration of climate, increase in food supply resulting from human activities, and reduced persecution (Nikula 1993). Increasing numbers occurred in the 1900s in southeastern Canada and the northeastern U.S., where nesting has occurred in several areas (Labrador to Maine and Massachusetts) beginning in the 1970s; U.S. nestings have been unsuccessful and population expansion does not seem to be on-going (Nikula 1993). See also Brown and Nettleship (1984). NON-BREEDING: in North America along Atlantic coast from Labrador, Newfoundland, New Brunswick, and Nova Scotia south to New York (Long Island), rarely farther south and west, and in Old World. In North America, the largest numbers occur in the St. John's/Conception Bay area, Newfoundland, where a peak of a couple hundred occurs in November, and in Nova Scotia around the Sydney/Glace Bay area and around Halifax (Nikula 1993). Casual in Hawaii, Puerto Rico, and along Pacific coast of North America. Regular in spring in Aleutian and Pribilof Islands.

This gull is widespread in Britain, in inland areas as well as by the coast (5). It is particularly common at inland sites in north England, Scotland and Wales (3). In winter the British population is augmented by birds from continental Europe (5). This gull has a wide global breeding range that extends through the Palaearctic (4).

In accordance with its common name, L. ridibundus is distinguished by its dark brown or grayish-black frontal hood. Its eye crescents (primarily behind the eye), neck, and underparts are all white as is the tail. The upper wing coverts, secondaries, inner primaries, and back are gray. The secondaries are tipped with white; the white outer primaries have black tips and edges. Other identifying characteristics of L. ridibundus include its red legs and bill, and dark brown eyes. Non-breeding adults have a white head, with only some blackish coloring on their nape. Juvenile birds are recognized by the beige to darker brown markings on their back and upper wing coverts. Also, they have a black terminal tail band. The species is sexually monomorphic. Larus ridibundus ranges from 37 to 43 cm in length and has a wingspan from 94 to 110 cm (Howard and Moore, 1991).

Range mass: 195 to 325 g.

Length: 41 cm

Weight: 284 grams

Length: 38-43 cm, Wingspan: 91-94 cm

Length: 34-43 cm. Plumage: back and wings pale grey; rump and tail white; head white with black smudge behind ear; below white; breeding adult with black hood; spread wing shows white leading edge forming wedge at shoulder with white outer primaries; trailing edge white except outer primaries which are tipped black. Immature shows more brown in wings than adult and has a blackish band at tip of tail . Bare parts: iris dark brown or red-brown; bill red, orange-red with black tip in immature; feet and legs red, dull orange in immature. Habitat: coastal and inland waters. Palearctic migrant. <389><391><393>

Habitat and Ecology

Systems

• Terrestrial
• Freshwater
• Marine

Larus ridibundus inhabits the temperate zone to the rim of the Palearctic boreal forests. It is found mostly at low attitudes and in or around placid, shallow coastal or inland water bodies, including rivers and their estuaries. In some areas, such as Scandinavia, it has adapted to settle in salt marshes, clay pits, and coastal dunes and offshore islands. The distribution of this highly adaptable species has increased to encompass areas near canals or sewage treatment facilities (Howard and Moore, 1991; Cantos et al., 1994).

Habitat Regions: temperate ; terrestrial

Aquatic Biomes: lakes and ponds; rivers and streams; coastal

Wetlands: marsh

Other Habitat Features: riparian ; estuarine

Depth range based on 2859 specimens in 1 taxon.
Water temperature and chemistry ranges based on 1045 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 1.627 - 13.837
  Nitrate (umol/L): 1.206 - 16.868
  Salinity (PPS): 6.218 - 35.485
  Oxygen (ml/l): 5.914 - 8.325
  Phosphate (umol/l): 0.231 - 0.890
  Silicate (umol/l): 0.987 - 12.889

Graphical representation

Temperature range (°C): 1.627 - 13.837

Nitrate (umol/L): 1.206 - 16.868

Salinity (PPS): 6.218 - 35.485

Oxygen (ml/l): 5.914 - 8.325

Phosphate (umol/l): 0.231 - 0.890

Silicate (umol/l): 0.987 - 12.889
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: ALL SEASONS: Lakes, rivers, bogs, moors, grasslands, swamps, and coastal marshes. NON-BREEDING: seacoasts, estuaries, and bays (AOU 1983). In Europe, also city parks and agricultural fields (Nikula 1993). Strongly attracted to sewer outfalls (Nikula 1993). BREEDING: Nests usually on ground along seacoast, coastal islands, or in freshwater marshes (Terres 1980).

Coastal waters, protected bays, estuaries. Range: Europe and Asia, coast of Northern Africa. East coast of North America.

In winter, found in a wide range of habitats including coastal marshes, farmland, rubbish tips, urban parks, gardens and playing fields (5). Usual breeding habitats include marshes, ponds, lakes, bogs, gravel pits and dry sites next to water bodies, such as sand-dunes and moorland (4) (3).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Some may spend summer in winter range along east coast (Terres 1980). Often returns to same wintering locale in successive years (Nikula 19930.

Winters in warmer parts of range.

Aquatic and terrestrial insects, earthworms, and marine invertebrates compose the bulk of L. ridibundus diet. This species also feeds on fish and grains, although to a lesser extent. Studies have shown that adults store greater nutrient reserves (fat and protein depots) not only for migration, but for reproductive activity as well.

This species forages by swimming and snatching food from the water surface, or by submerging its head under the water surface. These birds forage along coastal areas. Adults have more efficient foraging skills than do immature birds. Due to this inefficiency, immature birds feed in areas separate from the adult sites. Immature birds also display greater aggression, often winning fights over food. Interestingly, they are also more brazen in approaching humans, thus gaining a better chance to secure food.

The gulls are also kleptoparasitic on occasion, meaning that they steal food that has already been caught by a member of the same or different species. For example, in the Netherlands, sandwich terns (Sterna sandvicensis) nearly always stake their breeding ground in close proximity to colonies of L. ridibundus. In this arrangement, the gulls help protect the terns by driving out both avian and ground predators. The gulls, though, are major predators of tern eggs and chicks, and steal fish that tern parents have procured for their chicks. Larus ridibundus prefers to eat tern chicks up to two weeks old. Several scientists have suggested that kleptoparasitism occurs more often when other food sources are scarce.

Larus ridibundus displays high flexibility in diet. In western Europe, for instance, it has come to rely on human trash as an artificial food source. Researchers have attributed the significant increase in distribution of L. ridibundus to this influx of readily available food (Howard and Moore, 1991; Cantos et al., 1994; Stienen and Brenninkmeijer, 1999; Nuyts et al., 1996).

Animal Foods: birds; fish; eggs

Primary Diet: carnivore (Piscivore )

Comments: Highly opportunistic. Hawks for insects, searches muddy places for worms, plunges and dips into water for food, eats weed seeds and waste grain in fields, grasslands, and marshes, scavenges in harbors or mudflats where sewage discharged (Terres 1980).

Insects, earthworms, marine worms, mollusks, crustaceans, small fish, carrion, seeds and small fruits.

Animal / parasite / endoparasite
fluke of Diplostomum gasterostei endoparasitises Larus ridibundus

Larus ridibundus (Larus ridibundis black headed full) preys on:
Sprattus sprattus
Clupea harengus
Platichthys flesus
Crangon crangon
Nereis diversicolor
Neomysis integer
Corophium volutator
Gammarus

Based on studies in:
Scotland (Estuarine)

This list may not be complete but is based on published studies.

Larus ridibundus (Larus ridibundis black headed full) is prey of:
Cryptocotyle lingua
Himasthla elongata
Renicola roscorita
Psilostomum brevicolle
Maritrema gratiosum

Based on studies in:
Scotland (Estuarine)

This list may not be complete but is based on published studies.

In North America, often associates with flocks of migrant and wintering Bonaparte's gulls or other gulls (Nikula 1993).

Average lifespan
Status: wild: 218 months.

Maximum longevity: 63 years (wild)

Information on the mating system of these animals is not available.

After returning to its colonies between late February and late March, L. ridibundus lays its eggs in late April and May. Females lay from one to three eggs and incubate them for 22 to 26 days. Larus ridibundus is strongly inclined to nest near vegetation. At the very beginning of the breeding season, male L. ridibundus congregate in larges areas close to the nesting colony before females arrive. In these areas, termed "clubs," each bird is semi-territorial in that it does not stay in one particular area for a considerable amount of time. A male first regards visiting females as a threat, showing his aggressive oblique display and making long calls. In response, the female extends her neck upward and faces away, a display that makes her sex and potential as a mate known. The male then mitigates his response. The mating process continues when females keep coming back to a selected male, staying with him for progressively longer periods of time. The potential pair exchanges mutual displays. Their courtship culminates in the male regurgitating food for the female, an act followed by copulation.

As soon the pair of L. ridibundus settle into their colony area, they become territorial and defend their area against intruders (primarily conspecifics). They clearly mark their pairing territories, which range in size from 9 to 11 square meters. Their territorial boundaries are subject to slight changes as dictated by daily disputes with neighbors or intruders.

Colonies of L. ridibundus are made up of 11 to 100 breeding pairs; however, a few colonies reach numbers greater than 10,000 birds. These colonies are loosely divided: a breeding bird will eventually become accustomed to its neighbors, but will become very aggressive towards birds that it cannot recognize.

Research has shown that L. ridibundus is a philopatric species in which individuals are inclined to return to breed in the subcolony in which they were born. This tendency is especially evident within a large colony located in a relatively unstable habitat. Philopatry encourages the establishment of kin groups and eventually heightened cooperation among neighbors (Howard and Moore, 1991; Moynihan, 1955; Prevot-Julliard et al., 1998; Gill, 1995).

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization

Average time to hatching: 22 days.

Average eggs per season: 3.

Lays clutch of 3 eggs. Incubation reportedly 20-24 or 23-26 days. Young first fly at about 35-40 days. One banded bird lived over 32 years. Usually nests in large colonies in Eurasian range.

Nesting occurs mostly in colonies, sometimes as isolated pairs. Nest is built by both sexes in vegetation on the ground. 2-3 eggs incubated by both sexes for 23-26 days. Young are fed by both parents. Capable of first flights at around 5 weeks old.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 14
Specimens with Barcodes: 20
Species With Barcodes: 1

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 14 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Canada

Rounded National Status Rank: N3B,N4N : N3B: Vulnerable - Breeding, N4N: Apparently Secure - Nonbreeding

United States

Rounded National Status Rank: N3N - Vulnerable

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Larus ridibundus is not globally threatened, with a population approximated at two million pairs or perhaps more. As many as 1,500,000 to 1,800,000 have been estimated in Western Europe alone. From 1950 to 1980, this species underwent an impressive increase in numbers and subsequent increase in distribution (Howard and Moore, 1991).

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Regular passage visitor and winter visitor.

Rounded Global Status Rank: G5 - Secure

No official conservation status.

Included in the Birds of Conservation Concern Green List (low conservation concern) (3). Receives general protection in Great Britain under the Wildlife and Countryside Act (4).

Major Threats

Not threatened at present.

Conservation action has not been targeted at this species.