The Black-headed Gull is one of the most common gulls in Europe, in parts even endemic. This gull is not shy and follows into urban areas where it is, by now, also a very common apperance.
The Black-headed Gull is a medium sized gull at 34-43 cm length and a wingspan of c. 94-110 cm. Most prominent features of the adult summer moult are the dark head pattern, the red/brown-red pointed bull and the rather longish red-brown legs.
This article provides in-depth insight into breeding, distribution and threats on the Black-headed Gull.
Taxonomy:
Order: Charadriiformes
Family: Laridae
Genus: Larus
Species: Black-headed Gull
Scientific Name: Larus ridibundus
Name in German: Lachmöwe
Name in Czech: Racek chechtavý
Name in Slovak: Čajka smejivá
Name in Hungarian: Dankasirály
Name in Croat: Riječni Galeb
Name in French: Mouette rieuse
Name in Spanish: Gaviota Reidora
Name in Portuguese: Guincho-comum
Name in Dutch: Kokmeeuw
Name in Italian: Gabbiano comune
Name in Iceland: Hettumáfur
Name in Greenland: Nasalik
Name in Faroer: Fiskimási, Fiskimási
Name in Finnish: Naurulokki
Name in Danish: Hættemåge
Name in Swedish: Skrattmås
Name in Polish: Śmieszka
Name in Russian: Озёрная чайка
Name in Hebrew: שחף אגמים
Name in Arabic: النورس أسود الرأس, النورس أسود الرأس الجنة, نورس اسود الرأس
Name in Greek: Καστανοκέφαλος Γλάρος, Χωραφόγλαρος
Name in Turkey: Karabağ martı, Karabaş Martı, karabaş marty
Name in Kazahk: Кєл шағаласы
Name in Mongol: Хүрэн толгойт цахлай, Хүрэнтолгойт цахлай
Name in Japanese: Miyako-dori, yuri kamome, yurikamome, Yuri-kamome
Name in Korean: 붉은부리갈매기
Field Characteristics: Two-age groups. White leading edge to outer wing, when flying; also obvious blackish area bordering white leading edge of underwing, pointed wings. Upright posture when standing. Head pattern: dark brown hood in summer, in winter bold dark ear-spot. Longer neck and shorter tail. Red or brown-red legs and bill.
Bill: red or brown-red with dark tip.
Legs: red or brown-red.
Iris: dark.
Size: 34-43 cm
Weight:
♂: 195-300 g
♀: 250-400 g
Wingspan: 94-110 cm
♂: 28.2-32.3 cm
♀: 22.9-27.2 cm
Voice: Very noisy in colony and when feeding in flock. Utters sound like a shrill “kreareearr”.
Maturity: first breeding in third year.
Mating Season: monogamous breeding pair.
Clutches per breeding season1 clutch
Breeding: nest building begins c. 25 days before laying. In central Europa laying starts from early April at the earliest, mainly mid-April to end-April.
Nest: nest on dry platform, even on swimming platform in water, mainly in dry vegetation and on naked earth; nest made form large sticks, and green leaves. ♂ begins building nest, on which building continuous until end of breeding season.
Clutch: (1-2) 3 (rarely -4) eggs
Eggs: light creme-coloured broad oval egg with speckles and stains.
Egg Measurements:
Length: 41.0-69.0 mm
Width: 30.1-41.0 mm
Ø: 51.5x36.7 mm (n=1246, NL)
Egg weight: 26.0-42.0 g
shell weight: 1.55-2.72 g; Ø 2.03 g (n=500)
Recurrent Clutch: possibly when clutch is lost in the early days, in that case the nest site will be re-located.
Laying Interval: ca. 24 hours.
Begin of incubating: after laying the first egg.
Incubation: 1 egg = 25 days, for 2nd egg = 23.6 days, for third egg 21-27 days per egg, mainly 22-23 days on average. Both parents share the task of incubating.
Hatching: Hatchings takes about 48 hours per egg. On average it takes 12 hours between the first and second chicken hatching and 24 hours between second and third chicken hatching.
Fledging: Fledging after 26-28 days.
Dependency: Juveniles gain independence after c. 35 days.
Food: large variety: mainly omnivorous but also vegetarian, depending on food abundance; earth worms, insects such as beetles, bugs, larvae of click beetles (Elateridae), craneflies etc., flying insects, small fish, polychaetes, crustaceans, rubbish, carrion from small animals. Follows ships on sea in search of rubbish.
Longevity: The oldes known ringed bird of a Black-headed Gull reached an age of >32 years, also >30, 28 and 26 years.
Mortality: Mortality of c. 38% during first year, later mortality of c. 23% per annum.
Threats: Loss of habitat through ground melioration, conversion of grasslands into arable land, raising of water levels in swamps, siltation, destruction of siltation zones. Direct persecution. Heavy metals and biocides. Hunting, collection of eggs, poisoning. Loss of food in large areas, especially during breeding season. Predators such as large gulls, rats, foxes. Disturbances at colonies.
Bauer, Hans-Günther, Bezzel, Einhard et. al. (HG), Kompendium der Vögel Mitteleuropas, Band 1+2, Sonderausgabe 2012, Aula Verlag, Wiebelsheim
Bauer, Hans-Günther, Bezzel, Einhard et. al. (HG), Kompendium der Vögel Mitteleuropas, Band 3, Literatur und Anhang, Aula Verlag Wiebelsheim, 2. vollständig überarbeitete Auflage 1993
Bezzel, Einhard, Kompendium der Vögel Mitteleuropas, Non-Passeriformes, Band 1, AULA-Verlag Wiesbaden, 1985
Bruun/Singer/König/Der Kosmos Vogelführer, Franck'sche Verlagshandlung Stuttgart, 5. Auflage 1982
Glutz von Blotzheim, Urs et. al (HG), Handbuch der Vögel Mitteleuropas, Band 8/1, Charadriiformes (3. Teil), Akademische Verlagsgesellschaft Wiesbaden, 1982
Svenson, Lars et. al, Der Kosmos Vogelführer, Franck-Kosmos Verlag GmbH & Co. KG, Stuttgart, 2. Auflage 2011
Egg of Black-headed Gull - Source: by Algirdas, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1460012