Animal Diversity Web

Ge­o­graphic Range

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). (Can­tos, et al., 1994; Howard and Moore, 1991)

• Biogeographic Regions
• nearctic
  • native
• palearctic
  • native
• oriental
  • native

Habi­tat

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). (Can­tos, et al., 1994; Howard and Moore, 1991)

• Habitat Regions
• temperate
• terrestrial

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• coastal

• Wetlands
• marsh

• Other Habitat Features
• riparian
• estuarine

Phys­i­cal De­scrip­tion

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). (Howard and Moore, 1991)

• Other Physical Features
• endothermic
• bilateral symmetry

• Range mass

  195 to 325 g

  6.87 to 11.45 oz

Re­pro­duc­tion

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). (Gill, 1995; Howard and Moore, 1991; Moyni­han, 1955; Pre­vot-Jul­liard, et al., 1998)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• oviparous

• Average eggs per season

  3

  AnAge

• Average time to hatching

  22 days

  AnAge

Lifes­pan/Longevity

• Average lifespan
  Status: wild

  218 months

  Bird Banding Laboratory

Be­hav­ior

Three dis­plays sig­nal­ing ag­o­nis­tic be­hav­ior spe­cific to L. ridi­bun­dus have been iden­ti­fied in its young: the oblique, in which an erect pos­ture com­ple­mented by a se­ries of loud and stri­dent calls that de­crease in length; the for­ward, in which the neck is ex­tended, the head is in front of the body, and the bill is hor­i­zon­tal to the ground; and chok­ing, in which the bird leans to­ward the ground, points its bill down­ward and pro­ceeds to emit a soft call of short notes in rapid suc­ces­sion.

Ac­cord­ing to one study, at least six vari­ables de­ter­mined the out­come of a fight in L. ridi­bun­dus: own­er­ship (i.e. who ini­ti­ated the fight), semi­ter­ri­to­ri­al­ity, age, body mass, food avail­abil­ity, and lo­ca­tion. Sci­en­tists pro­pose that a bird might learn to shift from ob­vi­ous ag­gres­sion to the afore­men­tioned dis­plays when it re­al­izes that the lat­ter are just as ef­fec­tive in ward­ing off op­po­nents. This find­ing may help ex­plain why im­ma­ture L. ridi­bun­dus that have not yet learned the art of dis­play in­sti­gate and win more fights than adults, and also take more risks in in­ter­ac­tions with other species. It has been hy­poth­e­sized that fight­ing can be ben­e­fi­cial to im­ma­ture birds in that it helps them to gain "self-knowl­edge," (i.e. be­come aware of their own strengths).

In order to pro­tect it­self from preda­tors, L. ridi­bun­dus dis­plays both ag­gres­sive and flee­ing be­hav­iors. The type of be­hav­ior de­pends largely on the spe­cific preda­tor. For in­stance, preda­tors that pri­mar­ily take chicks and eggs, such as crows and larger gulls, war­rant ag­gres­sive be­hav­ior. At­tacks on adult birds by pere­grine fal­cons (Falco pere­gri­nus), how­ever, cause dense flocks to fly away. Threats to both adults and the brood, such as hu­mans and foxes, pre­cip­i­tate both ag­gres­sive and flee­ing be­hav­ior. Fac­tors like colo­nial nest­ing and breed­ing syn­chro­niza­tion help to keep preda­tors at bay (Groothuis and Van Mulekom, 1991; Nuyts et al., 1996; Kruuk, 1964). (Groothuis and Van Mulekom, 1991; Kruuk, 1964; Nuyets, et al., 1996)

• Key Behaviors
• flies
• motile
• migratory
• sedentary
• territorial
• colonial

Com­mu­ni­ca­tion and Per­cep­tion

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

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). (Can­tos, et al., 1994; Howard and Moore, 1991; Stienen and Bren­ninkmei­jer, 1999)

• Primary Diet
• carnivore
  • piscivore

• Animal Foods
• birds
• fish
• eggs

Con­ser­va­tion Sta­tus

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). (Howard and Moore, 1991)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  Protected

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

Al­though this is a Palearc­tic species, the num­bers of L. ridi­bun­dus in east­ern North Amer­ica have risen from the 1950s; it first bred in east­ern Canada in 1977. Today there are four known breed­ing sites of L. ridi­bun­dus in Canada and New Eng­land, but fewer than 20 breed­ing pairs (Howard and Moore, 1991). (Howard and Moore, 1991)

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Stephanie Hitz­taler (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Terry Root (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Can­tos, F., A. Alonso-Gomez, M. Del­gado. 1994. Sea­sonal changes in fat and pro­tein re­serves of the black-headed gull, Larus ridi­bun­dus, in re­la­tion to mi­gra­tion. Com­par­a­tive Bio­chem­i­cal Phys­i­ol­ogy, Vol. 108A, No. 1: 117-122.

Gill, F. 1995. Or­nithol­ogy. Sec­ond edi­tion.. W.H. Free­man and Com­pany.

Groothuis, T., L. Van Mulekom. 1991. The in­flu­ence of so­cial ex­pe­ri­ence on the on­to­ge­netic change in the re­la­tion be­tween ag­gres­sion, fear and dis­play be­hav­iour in black-headed gulls. An­i­mal Be­hav­iour, 42: 873-881.

Howard, R., A. Moore. 1991. A Com­plete Check­list of the Birds of the World. Sec­ond edi­tion.. Lon­don, San Diego: Aca­d­e­mic Press.

Kruuk, H. 1964. Preda­tors and Anti-Preda­tors of the Black-headed Gull (Larus ridi­bun­dus L.). Lei­den, The Nether­lands: E.J. Brill.

Moyni­han, M. 1955. Some As­pects of Re­pro­duc­tive Be­hav­ior in the Black-headed Gull (Larus ridi­bun­dus L.)and Re­lated Species. Lei­den, The Nether­lands: E.J. Brill.

Nuyets, E., A. Buit, E. Van der Zee. 1996. The in­flu­ence of age on the ac­quire­ment of a perch in the black-headed gull (Larus ridi­bun­dus L.): new data and a re­view of the lit­er­a­ture. Cana­dian Jour­nal of Zo­ol­ogy, 74: 1713-1720.

Pre­vot-Jul­liard, A., R. Pradel, J. Le­bre­ton, F. Cezilly. 1998. Ev­i­dence for birth-site tenac­ity in breed­ing Com­mon Black-headed Gulls, Larus ridi­bun­dus. Cana­dian Jour­nal of Zo­ol­ogy, 76: 2295-2298.

Stienen, E., A. Bren­ninkmei­jer. 1999. Keep the chicks mov­ing: how Sand­wich terns can min­i­mize klep­topar­a­sitism by black-headed gulls. An­i­mal Be­hav­iour, 57: 1135-1144.