Common Gull

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For the butterfly, see Cepora nerissa.
Common Gull
Adult Mew Gull. Anchorage Coastal Wildlife Refuge, Alaska.
Adult Mew Gull. Anchorage Coastal Wildlife Refuge, Alaska.
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Laridae
Genus: Larus
Species: L. canus
Binomial name
Larus canus
Linnaeus, 1758, Sweden

The Common Gull or Mew Gull (Larus canus) is a medium-sized gull which breeds in northern Asia, northern Europe and northwestern North America. It migrates further south in winter.[1]

Adults are 40-46 cm long, obviously smaller than the Herring Gull, and slightly smaller than the Ring-billed Gull, also differing from this in its shorter, more tapered bill with a more greenish shade of yellow, as well as being unmarked during the breeding season. The body is grey above and white below. The legs are greenish-yellow. In winter, the head is streaked grey, and the bill often has a poorly-defined blackish band near the tip (sometimes sufficiently obvious to cause confusion with Ring-billed Gull). They have black wingtips with large white "mirrors". Young birds have scaly black-brown upperparts and a neat wing pattern, and grey legs. They take two to three years to reach maturity. The call is a high-pitched "laughing" cry.[1][2]

Contents

[edit] Taxonomy

There are four subspecies, two of them considered distinct species by some authorities:[1][3]

  • Larus canus canus Linnaeus, 1758. Common Gull. Europe and western Asia. Small; mantle medium grey (palest subspecies); wingtips with extensive black; iris dark. Wingspan 110-125 cm; weight 290-480 g.
  • Larus canus heinei Homeyer, 1853. Central northern Asia. Medium size; mantle dark grey (darkest subspecies); wingtips with extensive black; iris dark. Weight 315-550 g.
  • Larus canus kamtschatschensis (Bonaparte, 1857); syn. L. kamtschatschensis. "Kamchatka Gull". Northeastern Asia. Large; mantle medium-dark grey; wingtips with extensive black; iris pale. Weight 394-586 g.
  • Larus canus brachyrhynchus Richardson, 1831; syn. L. brachyrhynchus. Mew Gull or "Short-billed Gull". Alaska and western Canada. Small; mantle medium-dark grey; wingtips with little black and much white; iris pale. Wingspan 96-102 cm; weight 320-550 g.

[edit] Ecology

Both Common and Mew Gulls breed colonially near water or in marshes, making a lined nest on the ground or in a small tree; colony size varies from 2 to 320 or even more pairs. Usually three eggs are laid (sometimes just one or two); they hatch after 24-26 days, with the chicks fledging after a further 30-35 days. Like most gulls, they are omnivores and will scavenge as well as hunt small prey. The global population is estimated to be about one million pairs; they are most numerous in Europe, with over half (possibly as much as 80-90%) of the world population.[4] By contrast, the Alaskan population is only about 10,000 pairs.[1]

[edit] Vagrancy

The Common Gull occurs as a scarce winter visitor to coastal eastern Canada and as a vagrant to the northeastern USA,[5] and there is one recent record of Mew Gull in Europe on the Azores.[6]

Common Gull Larus canus canus, Finland

Common Gull in winter plumage. Tallinn, Estonia.
A five part sequence depicting a Common Gull capturing a small fish in Helsinki, Finland.
A five part sequence depicting a Common Gull capturing a small fish in Helsinki, Finland.

[edit] References

  1. ^ a b c d del Hoyo, J., et al., eds. (1998). Handbook of the Birds of the World 3: 621. Lynx Edicions ISBN 84-87334-20-2.
  2. ^ Snow, D. W. & Perrins, C. M. (1998). The Birds of the Western Palearctic Concise Edition. OUP ISBN 0-19-854099-X.
  3. ^ Olsen, K. M., & Larsson, H. (2004). Gulls of Europe, Asia and North America. Helm ISBN 0-7136-7087-8.
  4. ^ Hagemeijer, W. J. M., & Blair, M. J., eds. (1997). The EBCC Atlas of European Breeding Birds. Poyser, London ISBN 0-85661-091-7.
  5. ^ Sibley, D. (2000). The Sibley Guide to Birds. ISBN 0-679-45122-6.
  6. ^ Alfrey, P., & Ahmad, M. (2007). Short-billed Gull on Terceira, Azores, in February-March 2003 and identification of the 'Mew Gull complex'. Dutch Birding 29 (4): 201-212.
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