Thick-billed Murre
| Thick-billed Murre | |
|---|---|
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| Adults in breeding plumage | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Subclass: | Neornithes |
| Infraclass: | Neognathae |
| Superorder: | Neoaves |
| Order: | Charadriiformes |
| Suborder: | Lari |
| Family: | Alcidae |
| Subfamily: | Alcinae |
| Tribe: | Alcini |
| Genus: | Uria |
| Species: | U. lomvia |
| Binomial name | |
| Uria lomvia (Linnaeus, 1758) |
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| Synonyms | |
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Alca lomvia Linnaeus, 1758 |
The Thick-billed Murre or Brünnich's Guillemot (Uria lomvia) is a bird in the auk family (Alcidae). This bird is named after the Danish zoologist Morten Thrane Brünnich. The very deeply black North Pacific subspecies Uria lomvia arra is also called Pallas' Murre after its describer.
It breeds on coasts and islands in the High Arctic of Europe, Asia and North America, where it is one of the most numerous bird species.
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[edit] Description
Since the extinction of the Great Auk in the mid-19th century, the murres are the largest living members of the Alcidae.[2] The Thick-billed Mure and the closely related Common Guillemot (or Common Murre, U. aalge) are similarly-sized, but the Thick-billed still bests the other species in both average and maximum size. The Thick-billed Murre measures 40–48 cm (16–19 in) in total length, spans 64–81 cm (25–32 in) across the wings and weighs 736-1481 g (1.6-3.3 lb).[3][4][5] The Pacific race (U. l. arra) is larger than the Atlantic race, especially in bill dimensions.[6]
Adult birds are black on the head, neck, back and wings with white underparts. The bill is long and pointed. They have a small rounded black tail. The lower face becomes white in winter. This species produces a variety of harsh cackling calls at the breeding colonies, but is silent at sea.
They differ from the Common Murre in their thicker, shorter bill with white gape stripe and their darker head and back; the "bridled" morph is unknown in U. lomvia - a murre has either a white eye-stripe, or a white bill-stripe, or neither, but never both; it may be that this is character displacement, enabling individual birds to recognize conspecifics at a distance in the densely-packed breeding colonies as the bridled morph is most common by far in North Atlantic colonies where both species of guillemots breed. In winter, there is less white on the Thick-billed Murre's face. They look shorter than the Common Murre in flight. First year birds have smaller bills than adults and the white line on the bill is often obscure, making the bill an unreliable way to identify them at this age. The head pattern is the best way to distinguish first-year birds from Common Murres.[7]
[edit] Ecology
These birds breed in large colonies on coastal cliffs, their single egg being laid directly on a cliff ledge. A description of the species breeding biology is given in detail by Gaston and Nettleship (1981).[8]
[edit] Migratory patterns
They move south in winter into northernmost areas of the north Atlantic and Pacific, but only to keep in ice-free waters. They are rare in temperate waters, staying below the 8 degree Celsius isotherm.
[edit] As a vagrant
Brünnich's Guillemot is a rare vagrant in European countries south of the breeding range. In Britain, over 30 individuals have been recorded, but over half of these were tideline corpses. Of those that were seen alive, only three have remained long enough to be seen by large numbers of observers. All three were in Shetland - winter individuals in February 1987 and November/December 2005, and a bird in an auk colony in summer 1989. The 1989 and 2005 birds were both found by the same observer, Martin Heubeck.
The species has been recorded once in Ireland,[9] and has also been recorded in the Netherlands. In the western Atlantic, they may range as far as South Carolina, and in the Pacific to California.[2] Before 1950 large numbers appeared on the North American Great Lakes in early winter, passing up the St. Lawrence River from the East coast. Such irruptions have not been seen since 1952.[10]
[edit] Flight and feeding characteristics
The Thick-billed Murre's flight is strong and direct, and they have fast wing beats due to the short wings. These birds forage for food like other auks, by using their wings to 'swim' underwater. They are accomplished divers, reaching depths of up to 150 m and diving for up to four minutes at a time; usually however birds make either shallow short dives or dive down to 21–40 m for longer periods.[11] Adults mainly eat invertebrates and a few fish and provision their chicks with fish, squid, some crustaceans and other small invertebrates.[12] They carry these prey items to their chicks, one at a time, in their bill. Birds will make long trips to get to favorite feeding grounds; while they usually forage several dozen km from their nest sites, they often travel more than 100 km to fish[13].[2]
The diving depths and durations regularly achieved by these birds indicate that they, and similar auks, have some - as yet unknown - mechanism to avoid diving sickness and lung collapse when surfacing.[11] It is postulated that auks temporarily absorb excess gases into the vascular structure of their bones. From there, it is gradually released from temporary storage in a controlled process of decompression.
[edit] Status and conservation
Egg harvesting and hunting of adult birds are major threats in Greenland, where populations fell steeply between the 1960s and 1980s.[14] In the Barents Sea region, the species has declined locally, due to influences associated with polar stations in Russia. Fisheries may be also be a threat, but because Thick-billed Murres are better able to utilise alternative food sources the effect of over-fishing is not as severe as on the Common Murre. Pollution from oil at sea exerts another major threat. Murres are among the seabirds most sensitive to oil contamination.[15] Incidental mortality brought on by entanglement with fishing gear is also an important cause of population decline.[16]
Thick-billed murres are closely associated with sea-ice throughout the year.[12] Consequently, some scientists believe that climate change may be a threat to this Arctic-breeding species.[17] However the species seems adaptable. Populations at the southern edge of their range switched from feeding on ice-associated Arctic cod to warmer-water capelin[18] as ice break-up became earlier. Dates for egg-laying advanced with the earlier disappearance of ice. The growth of chicks is slower in years when ice break-up is early relative to egg-laying by the murres. In extremely warm years, mosquitoes and heat kill some breeders.[19]
[edit] Notes
- ^ BirdLife International (2004). Uria lomvia. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
- ^ a b c Nettleship (1996)
- ^ [1]
- ^ [2]
- ^ [3]
- ^ Gaston & Jones (1998)
- ^ Gaston(1984)
- ^ Gaston & Nettleship (1981)
- ^ Mullarney, Killian (1988). "Brünnich's Guillemot in County Wexford - an addition to the Irish list". Irish Birds 3: 601–605.
- ^ Gaston (1988)
- ^ a b Croll et al. (1992)
- ^ a b Gaston & Hipfner (2000)
- ^ Lilliendahl et al. (2003)
- ^ Evans and Kampp (1991)
- ^ Wiese et al. (2003)
- ^ Bakken & Pokrovskaya (2000)
- ^ Gaston et al. (2005)
- ^ Gaston et al. (2003)
- ^ Gaston et al. (2002), Parmesan (2006)
[edit] References
- Bakken, Vidar & Pokrovskaya Irina V. (2000): Brünnich's Guillemot. In: Anker-Nilssen, T.; Bakken, Vidar; Strom, H.; Golovkin, A.N.; Bianki, V.V. & Tatarinkova, I.P. (eds.): The status of marine birds breeding in the Barents sea region. Norwegian Polar Institute Report Series 113: 119-124
- BirdLife International (2012). "Uria lomvia". IUCN Red List of Threatened Species. Version 2010.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/106003303. Retrieved 02 August 2012. Database entry includes justification for why this species is of Least Concern.
- Croll, Donald A.; Gaston, Anthony J.; Burger, Alan E. & Konnoff, Daniel (1992): Foraging behavior and physiological adaptation for diving in Thick-billed Murres. Ecology 73(1): 344-356. doi:10.2307/1938746 (HTML abstract, first page image)
- Evans, Peter, G.H & Kampp, K. (1991): Recent changes in Thick-billed Murre populations. In: Gaston, A.J & Elliot, R.D. (eds.): Studies of high-latitude seabirds: 2. Conservation biology of Thick-billed Murres in the Northwestern Atlantic. Canadian Wildlife Service Occasional Paper 69: 7-14.
- Gaston, Anthony J. (1984): How to distinguish first-year murres, Uria spp., from older birds in winter. Canadian Field-naturalist 98: 52-55.
- Gaston, Anthony J. (1988): The mystery of the murres: Thick-billed murres, Uria lomvia, in the Great Lakes region, 1890-1986. Canadian Field-naturalist 102: 705-711.
- Gaston, Anthony J.; Nettleship, David N. (1981): The Thick-billed murres of Prince Leopold Island. Environment Canada, Ottawa. ISBN 0-660-10857-7
- Gaston, Anthony J.; Jones, Ian L. (1998): The Auks: Alcidae. Oxford University Press, Oxford. ISBN 0-19-854032-9
- Gaston, Anthony J. & Hipfner, J. Mark (2000): The Thick-billed Murre. The Birds of North America Inc., Philadelphia, PA. ISSN 1061-5466
- Gaston, Anthony J.; Hipfner, J. Mark & Campbell, D. (2003): Heat and mosquitoes cause breeding failures and adult mortality in an Arctic-nesting seabird. Ibis 144: 185-191.
- Gaston, Anthony J.; Woo, Kerry & Hipfner, J. Mark (2003): Trends in Forage Fish Populations in Northern Hudson Bay since 1981, as Determined from the Diet of Nestling Thick-Billed Murres Uria lomvia [English with French abstract]. Arctic 56(3): 227–233. PDF fulltext
- Gaston, Anthony J.; Gilchrist, H.G. & Hipfner, J. Mark (2005): Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich's guillemot (Uria lomvia L.). Journal of Animal Ecology 74(5): 832–841. doi:10.1111/j.1365-2656.2005.00982.x (HTML abstract)
- Harrison, Peter (1988): Seabirds (2nd ed.). Christopher Helm, London. ISBN 0-7470-1410-8
- Lilliendahl, K.; Solmundsson, J.; Gudmundsson, G.A. & Taylor, L. (2003): Can surveillance radar be used to monitor the foraging distribution of colonially breeding alcids? [English with Spanish abstract] Condor 105(1): 145–150. DOI: 10.1650/0010-5422(2003)105[145:CSRBUT]2.0.CO;2 HTML abstract
- National Geographic Society (2002): Field Guide to the Birds of North America. National Geographic, Washington DC. ISBN 0-7922-6877-6
- Nettleship, David N. (1996): 3. Thick-billed Murre. In: del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.) (1996), Handbook of Birds of the World (Volume 3: Hoatzin to Auks): 710-711, plate 59. Lynx Edicions, Barcelona. ISBN 84-87334-20-2
- Parmesan, Camille (2006): Ecological and Evolutionary Responses to Recent Climate Change. Annu. Rev. Evol. Ecol. Syst. 37: 637–669. doi:10.1146/annurev.ecolsys.37.091305.110100 PDF fulltext
- Sibley, David Allen (2000): The Sibley Guide to Birds. Alfred A. Knopf, New York. ISBN 0-679-45122-6
- Wiese Francis K., Robertson Greg J. & Gaston Anthony J. (2003): Impact of chronic oil pollution and the murre hunt in Newfoundland on the Thick-billed Murre Uria lomvia populations in the eastern Canadian Arctic. Biological Conservation 116: 205–216.
[edit] External links
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Wikimedia Commons has media related to: Uria lomvia |
- Review of discussion about recent hunting regulations on Greenland. In Danish and English.
