Double White Lines on the Bill of the Razorbill Alca torda : Remnants of an Association with the Extint GreatAuk Penguinus impennis ?

• Main Authors: Lavers, JL, Muzaffar, SB, Jones, IL
• Format: Article in Journal/Newspaper
• Language: English
• Published: Seabird Group 2006
• Subjects: Biological Sciences; Ecology; Ecology not elsewhere classified; Canada; Alca torda; Great auk; Razorbill
• Online Access: http://www.seabirdgroup.org.uk/; http://ecite.utas.edu.au/78335

One of the diagnostic featuresof the Razorbill Alca torda is the distinct white line running vertically across the bill. Herewe report the presence of two white bill lines in 10 wintering Razorbills fromNewfoundland, Canada in addition to a small number of unreported birds from museumcollections and personal records. Populations of Razorbills across their range have beendivided into two major subspecies based on morphological variation, although molecularstudies do not support such a subdivision. Molecular phylogeny of the auks place Razorbillsas the closest relatives of the extinct Great Auk Penguinus impennis. Multiple white billlines were a characteristic of the Great Auk and we speculate that this variation in the billmarking in the Razorbill is an atavism, reflecting their common ancestry.