Stercorarius longicaudus

History:

• 1988-Lower Risk/least concern (BirdLife International 2004)
• 1994-Lower Risk/least concern (BirdLife International 2004)
• 2000-Lower Risk/least concern (BirdLife International 2000)

Justification

This species has a large range, with an estimated global extent of occurrence of 10,000,000 km². It has a large global population estimated to be 100,000¿500,000 individuals (del Hoyo et al. 1996). Global population trends have not been quantified, but populations appear to be stable (del Hoyo et al. 1996) so the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e., declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

Taxonomy

Notes:

Name Status: Accepted Name. Latest taxonomic scrutiny: 17-Oct-2001

Physical Description

Family Laridae:

Medium to large birds, usually grey or white, often with black markings on the head or wings. They have stout, longish bills, and webbed feet.

Images:

Distribution

Range and Population

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population estimated to be 100,000-500,000 individuals (del Hoyo et al. 1996). Global population trends have not been quantified, but populations appear to be stable (del Hoyo et al. 1996) so the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

North America

Diet

Mostly:

Fish Lesser Quantities of: Birds Small Mammals Eggs Carrion

Reproduction

• Clutch Size: 2
• Length of Incubation: 23-25 days
• Days to Fledge: 22-28
• Number of Broods: 1

Similar Species

Young Long-tailed Jaegers look superficially like first-year Herring Gulls but have a more powerful, direct flight and white patches on the primaries visible from above and below the wing. Skuas are similar as well but are bulkier and thicker-necked, with much more prominent wing patches. Jaegers look most similar to each other. Adult Long-tailed can be safely identified when their very long, pointed central tail feathers are seen. The adult light morph Long-tailed lacks the breast band that Parasitic and Pomarines have, and has gray, not dark brown upperparts contrasting with dark secondaries. Juvenile and subadult jaegers are very difficult to tell apart. The Pomarine has a heavier bill and is larger than the other species and juveniles have very short rounded tail feathers. Juvenile Parasitics often have distinctive cinnamon tones to their plumage, pale primary tips or wavy uppertail coverts. Juvenile and subadult Long-tailed Jaegers often look grayer than the other species and can have longer tails. Juvenile Long-tailed Jaegers typically have black and white wavy uppertail covert bars and axillaries, long rounded central tail feathers, just two white primary shafts, and a dark intrusion into the white primary patch from below.

Members of the genus Stercorarius:

There are approximately 23 species and subspecies in this genus: S. antarctica · S. antarcticus (Brown Skua) · S. antarcticus antarcticus · S. antarcticus hamiltoni · S. antarcticus lonnbergi · S. asiaticus · S. catarractes · S. chilensis (Chilean Skua) · S. longicaudus (Long-Tailed Jaeger) · S. longicaudus longicaudus (Long-Tailed Jaeger) · S. longicaudus pallescens · S. lonnbergi · S. maccormicki (South Polar Skua) · S. parasiticus (Parasitic Jaeger) · S. pomarinus (Pomarine Jaeger) · S. pomatorhinus · S. skua (Great Skua) · S. skua antarctica · S. skua chilensis · S. skua lonnbergi · S. skua maccormicki · S. skua skua · S. subgen.

Bibliography

• Banks, R. C., R. W. McDiarmid, A. L. Gardner, and W. C. Starnes 2003. Checklist of Vertebrates of the United States, the U.S. Territories, and Canada.
• BirdLife International. 2000. Threatened Birds of the World. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, U.K.
• Ehrlich, P., Dobkin, D., and Wheye, D. (1988). The Birders Handbook: A Field Guide to the Natural History of North American Birds. New York: Simon and Schuster Inc. (info on clutch size, length of incubation, days to fledge and number of broods.)
• Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc. (Length and wingspan info.)

More Info

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Notes

Contributors:

• Bisby, F.A., Y.R. Roskov, M.A. Ruggiero, T.M. Orrell, L.E. Paglinawan, P.W. Brewer, N. Bailly, J. van Hertum, eds (2007). Species 2000 & ITIS Catalogue of Life: 2007 Annual Checklist. Species 2000: Reading, U.K.
• Global Biodiversity Information Facility. Accessed December 08, 2007. http://www.gbif.org Mediated distribution data from 18 providers.

Data Sources:

Accessed through GBIF Data Portal December 08, 2007:

• Canadian Biodiversity Information Facility, North West Territories and Nunavut Bird Checklist, Canada
• Canadian Biodiversity Information Facility, Provincial Museum of Alberta, Edmonton, AB, Canada. Birds
• Canadian Biodiversity Information Facility, Royal British Columbia Museum

Identifiers:

• Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 176794
• Global Biodiversity Information Facility Taxonkey: 13810242
• Natural Heritage Network Species Identifier: ABNNM01030
• Zipcode Zoo Species Identifier: 178085