Great Black-backed Gull
Larus marinus (Linnaeus, 1758)
Family: Charadriiformes > Laridae
This impressive gull can be seen at coastal locations throughout the year, but it is less commonly encountered at inland sites.
Although Great Black-backed Gulls breed at coastal sites around much of our coast, they are absent from most of the North Sea coast. The highest breeding season densities are to be found around the Northern Isles, north-west Scotland and the Atlantic coast of south-west Ireland.
The pronounced pattern of winter abundance, which is greatest in the eastern half of Britain, underlines the arrival of wintering individuals from Scandinavia. Ringing data link these birds with populations in Norway and Sweden.
Select a topic for more facts and statistics about the Great Black-backed Gull
Great Black-backed Gull identification is sometimes difficult. The following article may help when identifying Great Black-backed Gull.
On paper Lesser and Great Black-backed Gulls are straightforward to separate but, in reality, many of us struggle - especially as the light conditions can alter their colour and size is not always apparent. Watch our video to tell these two species apart, as well as differentiate them from Herring Gull.
Listen to example recordings of the main vocalisations of Great Black-backed Gull, provided by xeno-canto contributors.
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Status and Trends
Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.
This species can be found on the following statutory and conservation listings and schedules.
Numbers of Great Black-backed Gull remained relatively stable between the 1969–70 Census and Seabird 2000 (1998–2002), with a very shallow decline of 11% (JNCC 2022 or link to website). Since Seabird 2000, annual monitoring suggests that this shallow decline may have continued although this is uncertain due to wide confidence limits and the recent trend may be stable: the latest Census results (2015–2021) may help clarify the trend once they are available (JNCC 2022 or link to website). The Great Black-backed Gull remains almost exclusively a coastal-breeding species, although a very small number of pairs have been recorded at inland colonies (Balmer et al. 2013).
|UK winter population||-42% decrease (1995/96 to 2020/21)|
Wintering Great Black-backed Gulls occur all around the coast of Britain & Ireland, as well as at inland, lowland sites in England and Scotland. Breeding birds have a predominantly coastal distribution around both Britain and Ireland, though they are largely absent from most of the North Sea coast between Lothian and Kent.
Occupied 10-km squares in UK
|No. occupied in breeding season||699|
|% occupied in breeding season||23|
|No. occupied in winter||2047|
|% occupied in winter||68|
European Distribution Map
Breeding Season Habitats
|Most frequent in||Open Shore|
Relative frequency by habitat
There has been a substantial 30% range contraction in Ireland since the 1968–72 Breeding Atlas, though much of this loss occurred between 1968–72 and 1988–91. A recent contraction is apparent in western Scotland but is outweighed by gains elsewhere in Britain, especially along the English south coast. Since the 1988–91 Breeding Atlas there has been a 7% increase in the number of 10-km squares occupied in Britain & Ireland.
Change in occupied 10-km squares in the UK
|% change in range in breeding season (1968–72 to 2008–11)||+2.7%|
|% change in range in winter (1981–84 to 2007–11)||--5.6%|
Great Black-backed Gulls are recorded throughout the year.
Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.
Lifecycle and body size information about Great Black-backed Gull, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.
View number ringed each year in the Online Ringing Report
|Maximum Age from Ringing||26 years 8 months 8 days (set in 2015)|
|Wing Length||Adults||473.9±20.3 | Range 438–513mm, N=215|
|Juveniles||473.6±15.9 | Range 446-495mm, N=26|
|Body Weight||Adults||1.56±0.21 | Range 1.29–1.92kg, N=185|
Feather measurements and photos on featherbase
|Field Codes||2-letter: GB | 5-letter code: GBBGU | Euring: 6000|
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Interpretation and scientific publications about Great Black-backed Gull from BTO scientists.
Causes of change
The Great Black-backed Gull has not suffered the substantial declines in populations that have recently affected several other UK seabirds including coastal breeding Herring and Lesser Black-backed Gulls. It has been surmised that this species out-competes other species when scavenging for fishery discards and offal and therefore may continue to be able to benefit from these resources despite reductions in availability which have affected other species (Mitchell et al. 2004).
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