Razorbills
The Razorbill is a seabird and a member of the auk family which also includes the Common Guillemot, Brunnich's Guillemot and Little Auk. It is also the closest living relative to the Great Auk which is now extinct.
The Razorbill has white underparts and a black head, neck, back and feet during the breeding season. A thin white line also extends from the eyes to the end of the bill. Its head is darker than that of the CommonGuillemot. Outside the breeding season, the throat and face behind the eye become white and the white line on the face becomes less prominent. The thick black bill has a blunt end. The adult male and female female are very much alike having only small differences such as wing length. The Razorbill has a horizontal stance and the tail feathers are slightly longer in the centre in comparison to other auks making it have a distinctly long tail which is not common for an auk.
The Razorbill is distributed across the sub-arctic and boreal waters of the north Atlantic where water surface temperature are typically below 15°c. The world population is estimated to be less than 1 million breeding pairs, making it among the rarest auks in the world. Approximately 60 to 70% of the entire Razorbill population breeds in Iceland., including over 200,000 pairs at Látrabjarg. The breeding habitat is islands, rocky shores and cliffs on north Atlantic coasts, in eastern North America as far south as Maine and in western Europe from north west Russia to northern France. Eurasian birds winter at sea with some moving south as far as the western Mediterranean. North American birds migrate offshore and south.
The Razorbill is a colonial breeder and only comes to land to breed. Individuals only breed at 3 to 5 years of age. Females select their mate and will often encourage competition between males before choosing a partner. Once a male is chosen, the pair will usually stay together for life. Nest site determination is very important to ensure protection of young from predators. Unlike Common Guillemots, nest sites are not immediately alongside the sea on open cliff ledges but at least 4 to 6 inches away in crevices on cliffs or among boulders. Generally a nest is not built although some pairs often use their bills to drag material upon which to lay their single egg. The mating pair will often reuse the same site every year.
The Razorbill feeds mainly on schooling fish and crustaceans and it will dive deep into the sea using its wings and its streamlined body to propel itself toward their prey. Whilst diving, it rarely stays in groups but instead spreads out to feed. The majority of feeding occurs at a depth of about 80 feet but it has the ability to dive up to 400 feet below the surface. During a single dive the Razorbill can capture and swallow many schooling fish depending on their size. The Razorbill spends approximately 45% of its time foraging at sea and it may well fly more than 60 miles out to sea to feed. However, when feeding chicks it will forage much closer to the nesting grounds and often in shallower water.
The Razorbill and its eggs and chicks have several predators which include Great Black-backed Gulls, Peregrines, Ravens and other crows, Arctic Foxes and Polar Bears. In the early 20th century, Razorbills were harvested for their eggs, meat and feathers and this greatly decreased their population. In 1917 they were finally protected which reduced hunting. Other current threats include oil pollution, unintentional bycatch arising from commercial fishing and overfishing which decreases the abundance of prey.
Date: 10th June 2019
Location: Handa Island, Highland
The Razorbill has white underparts and a black head, neck, back and feet during the breeding season. A thin white line also extends from the eyes to the end of the bill. Its head is darker than that of the CommonGuillemot. Outside the breeding season, the throat and face behind the eye become white and the white line on the face becomes less prominent. The thick black bill has a blunt end. The adult male and female female are very much alike having only small differences such as wing length. The Razorbill has a horizontal stance and the tail feathers are slightly longer in the centre in comparison to other auks making it have a distinctly long tail which is not common for an auk.
The Razorbill is distributed across the sub-arctic and boreal waters of the north Atlantic where water surface temperature are typically below 15°c. The world population is estimated to be less than 1 million breeding pairs, making it among the rarest auks in the world. Approximately 60 to 70% of the entire Razorbill population breeds in Iceland., including over 200,000 pairs at Látrabjarg. The breeding habitat is islands, rocky shores and cliffs on north Atlantic coasts, in eastern North America as far south as Maine and in western Europe from north west Russia to northern France. Eurasian birds winter at sea with some moving south as far as the western Mediterranean. North American birds migrate offshore and south.
The Razorbill is a colonial breeder and only comes to land to breed. Individuals only breed at 3 to 5 years of age. Females select their mate and will often encourage competition between males before choosing a partner. Once a male is chosen, the pair will usually stay together for life. Nest site determination is very important to ensure protection of young from predators. Unlike Common Guillemots, nest sites are not immediately alongside the sea on open cliff ledges but at least 4 to 6 inches away in crevices on cliffs or among boulders. Generally a nest is not built although some pairs often use their bills to drag material upon which to lay their single egg. The mating pair will often reuse the same site every year.
The Razorbill feeds mainly on schooling fish and crustaceans and it will dive deep into the sea using its wings and its streamlined body to propel itself toward their prey. Whilst diving, it rarely stays in groups but instead spreads out to feed. The majority of feeding occurs at a depth of about 80 feet but it has the ability to dive up to 400 feet below the surface. During a single dive the Razorbill can capture and swallow many schooling fish depending on their size. The Razorbill spends approximately 45% of its time foraging at sea and it may well fly more than 60 miles out to sea to feed. However, when feeding chicks it will forage much closer to the nesting grounds and often in shallower water.
The Razorbill and its eggs and chicks have several predators which include Great Black-backed Gulls, Peregrines, Ravens and other crows, Arctic Foxes and Polar Bears. In the early 20th century, Razorbills were harvested for their eggs, meat and feathers and this greatly decreased their population. In 1917 they were finally protected which reduced hunting. Other current threats include oil pollution, unintentional bycatch arising from commercial fishing and overfishing which decreases the abundance of prey.
Date: 10th June 2019
Location: Handa Island, Highland
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Also in: Auks
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