Alca torda
razorbill

The Razorbills are found in boreal and sub-Arctic waters of the Atlantic. Razorbills are exclusively an Atlantic species, with no counterpart in the North Pacific. It breeds between 73 degree north and 43 degree north from Hudson Strait and west Greenland south to the Gulf of Maine, and from Iceland Jan Mayen, Bjornoya and northwest Russia (White Sea), south to Brittany and the Baltic Sea. During the winter they are mostly offshore in northern boreal water south to Long Island, Azores and western Mediterranean. Their breeding colonies can be found on sea cliffs of Canada, Maine, Greenland, Iceland, Jan Mayen, Faeroe Island, Britain, Ireland, Brittany, France, Helgland, Germany, Denmark, Sweden, Finland, Norway, Bjornoya, Kola Peninsula and White Sea. (Nettleship & Birkhead, 1985)

Razorbill colonies occur on cliffs and offshore islands. They breed colonially in rocky, coastal regions on mainland cliffs and on offshore islands. In most areas breeding locations are situated in boulder screens or on cliff-faces in rock crevices or on ledges. Because the chicks cannot fly when they leave the colony, the breeding site must give immediate access to the sea. They feed in continental shelf waters, and usually feed rather close to shore than Common Murres (Uria aalge). Sometimes, Razorbills scatter among the Murres. (Gaston & Jone, 1998)

Razorbills are heavy-billed auks with an unusually long, rather graduated tail. During summer the head and the throat of adult Razorbills are black and dark chocolate brown. The under parts, including the under wing coverts, are white. There is a narrow white line extending forward from the eyes to the top of the bill. The gape is bright yellow and its iris is dark brown. Their legs and feet are black.

During winter the adult Razorbills are in their breeding plumage, but their throat, sides of neck, and face behind the eye are white. The vertical white line on the head and bill is less prominent.

The average weight for female Razorbills ranged from 505g to 730g. For males the weight ranged from 530g-720g. Average wing length for females ranged from 183mm-210mm. For males the wing length ranged from 182mm-206mm. (Wagner, 1999)

Razorbills are expert divers using their wings to swim underwater. The majority of dives consist of V-shaped dives in which Razorbills descend to a maximum depth and then start ascending. Most dives comprise of nonstop downward and upward movements to depths rarely greater than 35m, and never exceeding 43m. Average dive duration of birds feeding off the Isle of May, Scotland, was 35sec, implying, even at an underwater speed of 1.5m/sec, a mean maximum feeding depth of about 25m.

On the water and in flight Razorbills appears to be more agile than other auks. On land they usually squat on the tarsi and shuffle about, while maintaining a somewhat horizontal posture.

For Razorbill allopreening, mutual preening between pairs is common. It is a widespread ritualized form of agonistic behavior. It is usually directed at head, and neck and bout. Sometimes it may last for up to 6-7 minute. Several related behaviors involve signaling with the bill: bill clicking, in which mandible are clicked together while shaking head slowly from side to side; bill vibrating, where head is thrown back and lower mandible vibrates. (Gaston & Jones, 1998)

In general, adult Razorbills mainly feed on mid-water schooling fish: capelin, sandlance (Ammodytes), herrings (Clupea harengus), sprats (Sprattus sprattus), and juvenile cod. However, the species of the fish vary regionally. Adult Razorbills wintering off Newfoundland feed mainly on crustaceans. In Labrador the diet of adult Razorbills early in the season is largely capelin, but after the chicks hatch the adult take only some capelin but large numbers of small Myxocephalus sculpins and euphausiids. (Nettleship & Birkhead, 1985)

For the chicks, the parents usually bring one to six fish at a meal. Only occasionally do they bring up to 20 fish. Yet, the number of fish brought in a meal decreases as their size increases. The parents hold the fish crosswise in the bill to feed the chicks. Average length of fish brought to chicks varies in different regions. Sandlances that were brought to chicks in Irish Sea colonies were 53-79mm, yet, in Labrador they were 137mm. The diet of young Razorbills after they leave the colony is not known. (Nettleship & Birkhead, 1985)

Most auk chicks are vulnerable to predation from gulls during fledging. Razorbill chicks fledging asynchronously, either fairly early in the morning or late in the evening, are not protected. Therefore, they were more likely to be killed by gulls than those fledging synchronously. In other words, Razorbill chicks fledging not at the same time/rate are easier prey for gulls. (Nettleship & Birkhead, 1985)

Razorbills provide relatively large nutritious eggs, high in fat, having larger yolks than those of most terrestrial birds, as a result, they are easily targeted by red fox, raven and other predators. (Gaston & Jones, 1998)

Razorbills are carnivores (eating vertebrates) that are also eaten by other carnivores.

Ornithologists are studying the sexual behaviors among razorbills. They are/very likely to use Razorbill as a model to study avian mating behavior. (Carey, 1993)

After declining in the Gulf of St Lawrence during the 1970s, the species increased in the 1980s and is probably now as abundant as it has been in this century. The population of Britain and Ireland increased from 1970-1985, yet, the extent of increase is not known. (Gaston & Jones, 1998)

In 1997 there were experiments about whether egg size has the same effect on wing-feather growth in the Razorbill as in other birds. During the experiment eggs were switched randomly among pairs. The experimental study reported that chicks that hatched from large eggs grew their wing feathers more quickly than did small-egg chicks. The wings of large-egg chicks began fast, linear growth sooner, indicating that early development of wing feathers was by far superior in large-egg chicks. Differences in wing length established in this manner persisted through the nestling period. (Hipfner, 2000)