Razorbill (Alca Torda)

 

 

The French call it Petit pengouin. In fact the Razorbill looks like the smaller copy of a penguin. Other names attributed to the Razorbill are Razor-billed Auk or Lesser Auk. The Razorbill belongs to the Atlantic Auks which are also named "penguins of the northern hemisphere".

 

White breast, belly and legs, dark black back, wings, tail and head, and dark eyes on top of it.  The wings are short and narrow and it seems as if the bird would never make it into flight and up in the air. Trust me, they fly. White on the bill give the bird a distinctive appearane.

 

 

 

 

Geographical Variations

 

There are two subspecies existing and distributed over the entire distribution area:

  • Alca torda torda Linnaeus 1758 - distributed in the arctic, Baltic Sea, White Seas, Norway, Bear Island, Iceland, Greenland, eastern North America
  • Alca torda islandica C.L. Brehm 1831 - distributed in Ireland, Great Britain, northwest France - this species has smaller wings and is generally lighter than torda.

 

razorbill
Razorbill

 

Description - Characteristics: Razorbill

 

Breeding – Clutch – Measurements – Habitat – Diet - Threats

 

Taxonomy:

Order: Charadriiformes

Family: Alcidae

Genus: Alca

Species: Razorbill

 

Scientific Name: Alca torda

 

Names and Synonyms of the Razorbill

 

Name in German: Tordalk

Name in Czech: Alka malá

Name in Slovak: Alka vrúbkozobá

Name in Hungarian: Alka

Name in Croat: Oštrokljuna njorka

Name in French: Petit Pingouin

Name in Spanish: Alca Común

Name in Portuguese: Torda-mergulheira

Name in Dutch: Alk

Name in Italian: Gazza marina

Name in Iceland: Álka

Name in Faroer: Álka, Nakkalanga

Name in Greenland: Apparluk

Name in North Sami: Hálkka

Name in Finnish: Ruokki

Name in Danish: Alk

Name in Swedish: Tordmule

Name in Polish: Alka

Name in Russian: Гагарка

 

Distribution – Movements – Habitat - Behaviour

 

Distribution: The penguins of the northern hemisphere; North Atlantic and shorelines ov Canada, New England, from West Greenland to northwest France, North Sea and Baltics; White Sea in the northeast; Bear Island.

 

Movements: Migratory, spent most of the time out on the Atlantic.

 

Wintering: shores of Great Britain and Ireland, south Sweden, south Norway, Baltic Sea, Denmark, Atlantic coast of France, Spain and Portugal and further south to Morocco; torda mainly winters in the breeding areas.

 

Habitat: Spents most of the year out on the ocean, on shores, offshore in winter, colonial on cliffs and rocky islands.

 

Behaviour: Activity during daytime and at twilight. Flies close to water surface. Dives ony a few metres deep. Mostly gregarious.

 

 

Field Characteristics: Big head, short neck, high and slender bill with perpendicular white line close to centre of bill. Relatively large pointed tail. Black plumage, back and wings and dark eyes, white chest, belly and undertail coverts, white feather tips at secondaries. White line from upper bill to eye.

 

Bill: black.

Tarsus: Black.

 

Iris: dark-brown.

 

Measurements

 

Size: 37-39 cm

Weight: 524-890 g

372-645 g (islandica)

Wingspan: 63-68 cm

Wing: 20.1-21.6 cm

18.7-20.0 cm (islandica)

 

Voice: Deep aarh.

 

razorbill egg collection museum wiesbaden
Egg of the Razorbill - source: by Klaus Rassinger and Gerhard Cammerer, Museum Wiesbaden - own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=35759116

 

Clutch: 1 egg

Eggs: long-oval, base colour white to brown or greenish, with variety in stains.

Egg Measurements:

Length: 64.4-84.2 mm

Width: 41.0-52.0 mm

Ø: 75.3x48.0 mm (n=167)

Egg weight: 80.0-107.0 g (n=92)

shell weight: 6.5-12.7 g; Ø = 8.7 g (n=250)

 

Recurrent Clutch: mainly another egg is layed within the first 18 days after loss; even two clutches are possible.

 

Incubation: 28-43 days, Ø 36 days; both parents share the task of incubating.

 

Hatching: It takes 48-90 hours (Ø 72±16 hours) from first crack in the shell to the chicken fully free of the shell.

 

Fledging: Depends on geographical area: 14-22 days (Ø 17-18 days) in boreal zones, 19-22 days in subarctic zones. Both parents feed the juvenile. Juveniles jump off cliff ledges after 14-22 days, parents lead juveniles to the ocean where they swim for quite a while before finally fledging.

 

Dependency: After jumping off the cliffs juveniles are dependent on their parents for several weeks.

 

 

Miscellaneous

 

Food: pelagic fish, sprats, sandeels, gobiidae; herring in winter; also sticklebacks and crustaceans.

 

Longevity: Oldest known ringed bird of a Razorbill reached an age of 30 years and 1 months.

 

Mortality: Adults are subjected to a mortality rate of 8-10% per annum; the mortality rate for immatures is c. 62%.

 

Threats: Currently large losses of individuals through oil pollution, drowning in fishing nets and high levels of pollution. Hunting is no longer the main threat, if any then locally.