Pelagic Cormorant
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| Phalacrocorax pelagicus Pallas, 1811 |
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Phalacrocorax kenyoni |
The Pelagic Cormorant (Phalacrocorax pelagicus[1]), also known as Baird's Cormorant, is a small (25"-29", 64-74 cm long) member of the cormorant family found on the coasts of the northern Pacific.
It is a black-bodied seabird with a metallic gloss. Its facial skin is a vivid magenta.
It is distinguished from other cormorants in the region by its small head and much thinner bill. Also, it is the only cormorant in its region that has conspicuous white patches on its flanks during the breeding season.
This bird feeds by diving into wild seas and surf near boulders. It can dive as deep as 100 feet (30 m) in coastal waters to feed on the sea bottom.
The Pelagic Cormorant's USA range includes the Pacific shore from Alaska to the Baja peninsula in Mexico.
Kenyon's Shag or Amchitka Cormorant (Phalacrocorax kenyoni[2]) is a supposed species, closely related to the Pelagic Cormorant, which was described from the bones of two individuals snared in fishing nets at Amchitka Island in the late 1950s (Siegel-Causey, 1991). Later, some bones from prehistoric middens were also attributed to this taxon. As distinctive cormorants were never seen alive in recent years on Amchitka, it was conjectured by some that Kenyon's Shag had gone extinct in the 1960s-1970s (marine pollution and overfishing would be possible reasons).
However, a subsequent analysis of a larger number of comparison specimens of the Pelagic Cormorant (Rohwer et al., 2000) determined that the bones were attributable to small females of the latter species. The researchers also found that contrary to what was generally assumed, Pelagic Cormorants from Amchitka were generally small birds, as opposed to Eastern Aleutian individuals which are usually very large. If the Amchitka/Western Aleutian population were to be considered a distinct subspecies (which would require molecular analyses since the differences in morphology are not large and there is much variation between individuals), the name kenyoni would apply. The largest birds were formerly called P. pelagicus robustus but are not considered distinct today; since there appear to be 3 recognizable size groups in the northern subspecies alone, more research is clearly warranted (Hobson, 1997).
[edit] References
- BirdLife International (2004). Phalacrocorax pelagicus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 10 May 2006. Database entry includes justification for why this species is of least concern
- Hobson, K. A. (1997): Pelagic Cormorant (Phalacrocorax pelagicus). In: Poole, A. & Gill, F. (eds.): The Birds of North America 282. The Academy of Natural Sciences, Philadelphia, PA & The American Ornithologists' Union, Washington, D.C. Online version, retrieved 2006-OCT-10.
- Rohwer, Sievert; Filardi, Christopher E.; Bostwick, Kimberly S. & Peterson, A. Townsend (2000): A critical evaluation of Kenyon's Shag (Phalacrocorax [Stictocarbo] kenyoni). Auk 117(2): 308–320. PDF fulltext
- Siegel-Causey, Douglas (1991): Systematics and biogeography of North Pacific shags, with a description of a new species. Occasional Papers of the University of Kansas Museum of Natural History 140: 1–17.
- Siegel-Causey, Douglas; Lefevre, C. & Savinetskii, A. B. (1991): Historical diversity of cormorants and shags from Amchitka Island, Alaska. Condor 93(4): 840–852. PDF fulltext
[edit] Footnotes
- ^ Phalacrocorax, Latinized Ancient Greek for cormorants (literally "bald raven"). pelagicus, Ancient Greek for "of the open seas" (cf. pelagic).
- ^ kenyoni, dedicated to Karl W. Kenyon who collected the type specimen in 1959.
