Western gulls and
glaucous-winged gulls hybridise extensively in western
North America between Washington and Oregon. This particular hybrid is sometimes known as the "Olympic gull", or "Puget Sound gull".[1] The persistence and backcrossing of hybrids is believed to be due to hybrid superiority, where hybrids exhibit higher evolutionary fitness than parent species in the hybrid zone. [2]
Great black-backed gulls and
herring gulls have hybridized in eastern North America, particularly the Great Lakes. This hybrid is sometimes known as "Great Lakes gull".
Herring gulls and
glaucous gulls hybridise in Greenland, Iceland and Alaska. The offspring have been termed "Nelson's gull",[3] but are sometimes also known as "Viking gull".
Herring gulls and
kelp gulls have hybridized in Louisiana. This combination has been termed "Chandeleur gull". This hybrid is interesting as Louisiana is outside of the normal breeding range of both parent species.
Glaucous-winged Gull and
Slaty-backed Gull hybridize in western Alaska and possibly eastern Siberia. A name for this combination has been emerging as "Commander" Gull, after the Commander Islands off of eastern Russia. Some speculate most Glaucous-winged Gulls wintering in Asia have hybrid origins.
It is believed by some that the Kumlien's race of the
Iceland gull may be a hybrid population between
Iceland gulls and
Thayer's gulls. No pure Thayer's gulls are known to occur within the range of Kumlien's although many Kumlien's within their range are almost indistinguishable from Thayer's gulls, while others look like pure Iceland gulls with a range of variation in between.
Hybrids among the smaller gulls
The most common hybrid found among gulls in
Europe is between
black-headed gull and
Mediterranean gull. Hybrids of this combination are occasionally reported on the northwestern edge of the breeding range of Mediterranean gull.[citation needed]
Birds have also been reported in Europe which have been suspected of being Mediterranean gull ×
common gull hybrids; one such gull was seen in
Lincolnshire in 2002.[4]
A bird seen in December 2001 at
Belhaven Bay,
Lothian, and present each winter since (until at least 2005/6) is believed to be a hybrid between black-headed and common gulls.[5]
More rarely, hybrids have been reported between
laughing gull and
black-headed gull, laughing gull and
ring-billed gull and possibly black-headed and ring-billed gull. All have been reported from eastern North America.
^Tarrant, Mike (2002) An apparent hybrid gull in Lincolnshire Birding World Vol. 15 No. 6 p247
^Gillon, Keith (2006) An apparent hybrid gull at Belhaven Bay, Lothian Birding Scotland Vol. 9 No. 2 p92
^Charles, D. (2008) Ring-billed Gull breeding with Common Gull on Copeland Islands Co. Down. The first confirmed breeding record for Ring-billed Gull in the Western Palearctic. Northern Ireland Bird Report xviii p. 122.
Western gulls and
glaucous-winged gulls hybridise extensively in western
North America between Washington and Oregon. This particular hybrid is sometimes known as the "Olympic gull", or "Puget Sound gull".[1] The persistence and backcrossing of hybrids is believed to be due to hybrid superiority, where hybrids exhibit higher evolutionary fitness than parent species in the hybrid zone. [2]
Great black-backed gulls and
herring gulls have hybridized in eastern North America, particularly the Great Lakes. This hybrid is sometimes known as "Great Lakes gull".
Herring gulls and
glaucous gulls hybridise in Greenland, Iceland and Alaska. The offspring have been termed "Nelson's gull",[3] but are sometimes also known as "Viking gull".
Herring gulls and
kelp gulls have hybridized in Louisiana. This combination has been termed "Chandeleur gull". This hybrid is interesting as Louisiana is outside of the normal breeding range of both parent species.
Glaucous-winged Gull and
Slaty-backed Gull hybridize in western Alaska and possibly eastern Siberia. A name for this combination has been emerging as "Commander" Gull, after the Commander Islands off of eastern Russia. Some speculate most Glaucous-winged Gulls wintering in Asia have hybrid origins.
It is believed by some that the Kumlien's race of the
Iceland gull may be a hybrid population between
Iceland gulls and
Thayer's gulls. No pure Thayer's gulls are known to occur within the range of Kumlien's although many Kumlien's within their range are almost indistinguishable from Thayer's gulls, while others look like pure Iceland gulls with a range of variation in between.
Hybrids among the smaller gulls
The most common hybrid found among gulls in
Europe is between
black-headed gull and
Mediterranean gull. Hybrids of this combination are occasionally reported on the northwestern edge of the breeding range of Mediterranean gull.[citation needed]
Birds have also been reported in Europe which have been suspected of being Mediterranean gull ×
common gull hybrids; one such gull was seen in
Lincolnshire in 2002.[4]
A bird seen in December 2001 at
Belhaven Bay,
Lothian, and present each winter since (until at least 2005/6) is believed to be a hybrid between black-headed and common gulls.[5]
More rarely, hybrids have been reported between
laughing gull and
black-headed gull, laughing gull and
ring-billed gull and possibly black-headed and ring-billed gull. All have been reported from eastern North America.
^Tarrant, Mike (2002) An apparent hybrid gull in Lincolnshire Birding World Vol. 15 No. 6 p247
^Gillon, Keith (2006) An apparent hybrid gull at Belhaven Bay, Lothian Birding Scotland Vol. 9 No. 2 p92
^Charles, D. (2008) Ring-billed Gull breeding with Common Gull on Copeland Islands Co. Down. The first confirmed breeding record for Ring-billed Gull in the Western Palearctic. Northern Ireland Bird Report xviii p. 122.