Razorbill

From SongbirdReMixWiki

Jump to: navigation, search

Image:Razorbill.JPG

Common Name: Razorbill
Scientific Name: Alca torda

Size: 16.9 inches (43 cm); 63–68 cm wingspan

Habitat: Northern Hemisphere; distributed across sub-arctic and boreal waters of the Atlantic. Their breeding habitat is islands, rocky shores and cliffs on northern Atlantic coasts, in eastern North America as far south as Maine, and in Western Europe from northwestern Russia to northern France. North American birds migrate offshore and south, ranging from the Grand Banks of Newfoundland to New England. Eurasian birds also winter at sea, with some moving south as far as the western Mediterranean. Approximately 60 to 70 percent of the entire razorbill population breeds in Iceland.

Status: Least concern. Global Population: 500,000-700,000 mature individuals. In 1917, Razorbills were put under the protection of the “Migratory Bird Treaty Act”. Since then populations are thought to be stable or increasing throughout major parts of its global range. The current threat for the razorbill population is the destruction of breeding sites and the conservative elements of the US Government wanting to dismantle the “Migratory Bird Treaty Act”, claiming it is “bad for business”.

Diet: Fish; especially sandeels, sprats and herrings. Razorbills dive underwater to capture their prey, using their wings to swim.

Breeding: Male and female look alike, though females are slightly smaller. Throughout the pre-laying period razorbills will socialize in large numbers. There are two types of socializing that occur. Large groups will dive and swim together in circles repeatedly and all rise up to the surface, heads first and bills open. Secondly, large groups will swim in a line weaving across each other in the same direction.

Razorbills will choose only one partner for life and females will lay one egg per year. The pair will mate up to 80 times in a 30 day period to ensure fertilization.

Razorbills will nest along coastal cliffs in enclosed or slightly exposed crevices and will only come to land in order to breed. Both parents will spend equal amount of time incubating. Once the chick has hatched, the parents will take turns foraging for their young and will sometimes fly long distances before finding prey.

Cool Facts: It is the largest living member of the Auk family. Razorbill's average lifespan is roughly 13 years, although a bird ringed in the UK in 1967 has survived for at least 41 years—a record for the species.

There are two subspecies of Razorbill recognized by the American Ornithologists' Union. Alca torda torda, named by Linnaeus in 1758, occurs in eastern North America, Greenland, Bear Island (Norway) and the Baltic and White Seas. Alca torda islandica was named by C. L. Brehm in 1831 and occurs throughout the British Isles and Northwestern France. The two subspecies differ slightly in bill measurements. A third suspecies, Alca torda pica, is no longer recognized because the distinguishing characteristic, an additional furrow in the upper mandible, is now known to be age-related.


Found in Songbird ReMix Seabirds Volume 2

Personal tools