Razorbill

Last updated

Razorbill
Razorbill with a nice catch.jpg
On Stora Karlsö, Gotland, Sweden
Pair of Razorbills calling, recorded on Skokholm, Wales
Status iucn3.1 LC.svg
Least Concern  (IUCN 3.1) [1] (Global)
Status iucn3.1 LC.svg
Least Concern  (IUCN 3.1) [2] (Europe)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Alcidae
Genus: Alca
Species:
A. torda
Binomial name
Alca torda
Subspecies [3]
  • A. t. torda - Linnaeus, 1758
  • A. t. islandica - Brehm, CL, 1831
Alca torda map.svg

The razorbill (Alca torda) is a North Atlantic colonial seabird and the only extant member of the genus Alca of the family Alcidae, the auks. It is the closest living relative of the extinct great auk (Pinguinus impennis). [4] Historically, it has also been known as "auk", [5] "razor-billed auk" [6] and "lesser auk". [7]

Contents

Razorbills are primarily black with a white underside. The male and female are identical in plumage; however, males are generally larger than females. This agile bird, which is capable of both flight and diving, has a predominantly aquatic lifestyle and only comes to land in order to breed. It is monogamous, choosing one partner for life. Females lay one egg per year. Razorbills nest along coastal cliffs in enclosed or slightly exposed crevices. The parents spend equal amounts of time incubating, and once the chick has hatched, they take turns foraging for their young.

Presently, this species faces major threats, including the destruction of breeding sites, [8] oil spills, [9] and deterioration of food quality. The IUCN records the population of the species as fluctuating, [1] causing its status to interchange. It has been recorded that the population had increased from 2008 to 2015, [10] decreased from 2015 to 2021, [11] and appears to be increasing or stable at the present. [1] It is estimated that the current global razorbill population lies between 838,000 to 1,600,000 individuals. [1] In 1918, the razorbill was protected in the United States by the Migratory Bird Treaty Act.

Taxonomy

In flight off Skomer Island Razorbill (Alca torda) in flight.jpg
In flight off Skomer Island

The genus Alca was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae . [12] The genus name Alca is from Norwegian Alke, and torda is from törd a Gotland Swedish dialect word; both terms refer to this species. [13] The type locality is Stora Karlsö, just off the west coast of Gotland, Sweden. [14] The word Alca had been used by earlier authors for the razorbill such as Carolus Clusius in 1605 [15] and Francis Willughby in 1676. [16]

The razorbill is now the sole species in the genus Alca, [17] though its close relative, the great auk (Pinguinus impennis), which became extinct in the mid-19th century, was also formerly included in the genus Alca. [12] Razorbills and great auks are part of the tribe Alcini, which also includes the common murre or common guillemot (Uria aalge), the thick-billed murre or Brünnich's guillemot (Uria lomvia), and the Little auk (Alle alle). [18]

There are two subspecies of razorbill accepted by the IOC: [17]

ImageSubspeciesDistribution
Razorbills.jpg
Stora Karlsö, Gotland, Sweden		Alca torda torda Linnaeus 1758the Baltic and White Seas, Norway, Bear Island, Greenland, and eastern North America.
Razorbills and Puffins.jpg
Látrabjarg, Iceland (with Atlantic puffins to the right)		Alca torda islandica C.L. Brehm 1831 Iceland (type locality), Ireland, Great Britain, northwestern France, and Heligoland, Germany.

The two subspecies differ slightly in size and bill measurements, with A. t. islandica, which occurs in warmer waters, being slightly smaller. [14] A third subspecies Alca torda pica Linnaeus, 1766 (originally described as a species Alca pica from the Arctic, [19] and reduced to subspecies by Salomonsen in 1944 [20] ), is no longer accepted because the distinguishing characteristic, an additional furrow in the upper mandible, is now known to be age-related. [14]

Description

Courting on Skomer Island Razorbill (Alca torda) pair.jpg
Courting on Skomer Island

The razorbill has a white belly 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 a common murre. During the non-breeding season, the throat and face behind the eye become white, and the white line on the face and bill becomes less prominent. [21] The bill is black, deep and laterally compressed, with a blunt end. It has several vertical grooves or furrows near the curved tip, one of them adorned with a white, broken vertical line. The bill is thinner and the grooves are less marked during the non-breeding season. It is a large and thick-set bird for an alcid, and its mean weight ranges from 505 to 890 g (17+3⁄4 to 31+1⁄2 oz). [22] The female and male adults are very much alike, having only small differences such as wing length. It is 37–39 cm in body length, the wing length of adult males ranges from 201–216 mm (7+15⁄16–8+1⁄2 in) while that of females ranges from 201 to 213 mm (7+15⁄16 to 8+3⁄8 in). [23] During incubation, this species has a horizontal stance and the tail feathers are slightly longer in the center in comparison to other alcids. This makes the razorbill have a distinctly long tail which is not common for an auk. In-flight, the feet do not protrude beyond the tail.

Their mating system is female-enforced monogamy; the razorbill pairs for life. It nests in open or hidden crevices among cliffs and boulders. It is a colonial breeder and only comes to land to breed. The annual survival rate of the razorbill is between 89 and 95%. [24] Though the razorbill's average lifespan is roughly 13 years, a bird ringed in the UK in 1967 survived for at least 41 years—a record for the species. [25]

Distribution and habitat

Razorbills are distributed across the North Atlantic; the world population of razorbills is estimated to be at less than 1,000,000 breeding pairs (Chapdelaine et al. 2001). Approximately half of the breeding pairs occur in Iceland. Razorbills thrive at water surface temperatures below 15 °C. They are often seen with the two larger auks, thick-billed murre and common murre. However, unlike other auks, they commonly move into larger estuaries with lower salinity levels to feed. These birds are 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 Labrador Sea south to the Grand Banks of Newfoundland to New England. Eurasian birds also winter at sea, with multiple populations aggregating in the North Sea [26] and some moving south as far as the western Mediterranean. Approximately 60 to 70% of the entire razorbill population breeds in Iceland. [27]

Some razorbill colonies include (north to south):

Behaviour

Taking off from water Razorbill (Alca torda) taking off.jpg
Taking off from water

The life-history traits of the razorbill are similar to that of the common murre. However, razorbills are slightly more agile. In North America it is a largely migratory seabird, as during the colder months, it leaves land and spends the entire winter in the waters of the Atlantic Ocean, [34] though western European birds often remain close to their breeding sites.

During breeding, both males and females protect the nest. Females select their mate and will often encourage competition between males before choosing a partner. [35] Once a male is chosen, the pair will stay together for life.

Reproduction

Individuals only breed at 3–5 years old. As pairs grow older they will occasionally skip a year of breeding. A mating pair will court several times during breeding periods to strengthen their bond. [22] Courtship displays include touching bills and following one another in elaborate flight patterns. Once the pre-laying period begins, males will constantly guard their mates by knocking other males away with their bills. [22] The pair will mate up to 80 times in a 30-day period to ensure fertilisation. [36] Females will sometimes encourage other males to engage in copulation to guarantee successful fecundity. [35]

Throughout the pre-laying period, razorbills will gather in large numbers. Two types of social behaviour occur; large groups dive and swim together in circles repeatedly and all rise up to the surface, heads first and bills open; secondly, large groups swim in a line weaving across each other in the same direction.

Nest sites

Banded chick on Gannet Island, Labrador Banded Razorbill chick.jpg
Banded chick on Gannet Island, Labrador

Nest site choice is very important for these birds to ensure the protection of the young from predators. Unlike murres, nest sites are not immediately alongside the sea on open cliff ledges but at least 10 cm (4 in) away, in crevices on cliffs or among boulders. Nests are usually confined among the rocks or slightly more open. Some sites are along ledges, however, crevice sites seem to be more successful due to reduced predation. [37]

The mating pair will often reuse the same site every year. [38] [39] Since chicks cannot fly, nests close to the sea provide easy access when leaving the colony. Generally, razorbills do not build a nest; however, some pairs may use their bills to drag material upon which to lay their egg. [40] Nest under a boulder, rarely on an exposed ledge, may use Puffin or rabbit burrow. [41] Although gregarious in breeding colonies, nests are not contiguous, but some metres apart, resulting in less aggression than in Guillemot colonies. [41]

Incubation and hatching

Egg Alca torda MHNT Ile Rouzic.jpg
Egg

Females lay a single egg per year, usually from late April to May. The egg is an ovoid-pyramidal shape, creamy white to pale brown with has dark brown blotches. Incubation starts generally 48 hours after laying the egg. Females and males take turns incubating the egg several times daily for a total of approximately 35 days before hatching occurs. Razorbill chicks are semi-precocial. [42] During the first two days after hatching, the chick will spend the majority of its time under the parent's wing. There is always one parent at the nest site while the other goes to sea to collect food for the chick. The hatchling develops a complete sheath 10 days after hatching. After 17–23 days, the chick leaves the nest by jumping from a cliff, closely followed by the male parent, who will accompany the chick to sea. During this time, the male parent will dive more than the female parent. [43]

Feeding

Razorbills dive deep into the sea using their semi-folded wings and their streamlined bodies to propel themselves toward their prey. They keep their feet spread. While diving, they rarely stay in groups but rather spread out to feed. The majority of their feeding occurs at a depth of 25 m (80 ft) but they have the ability to dive up to 120 m (395 ft) below the surface. [44] During a single dive, an individual can capture and swallow many schooling fish, depending on their size. Razorbills spend approximately 44% of their time foraging at sea. [45]

When feeding their young, they generally deliver small loads. Adults will mainly feed only one fish to their chick with high feeding deliveries at dawn and decreased feeding 4 hours before dark. [22] Females will generally feed their chicks more frequently than males. [45] They may fly more than 100 km (60 mi) out to sea to feed when during egg incubation, but when provisioning the young, they forage closer to the nesting grounds, some 12 km (7+1⁄2 mi) away, and often in shallower water. [28]

Diet

The diet of razorbill is very similar to that of a common murre or common guillemot. It consists generally of mid-water schooling fish such as capelin, sandeels, juvenile cod, sprats, and herring. It may also include crustaceans and polychaetes. A recent study suggests the diet is affected by local and regional environmental conditions in the marine environment. [39]

Predators

The adult razorbill has several predators which include great black-backed gulls, peregrine falcons, ravens, crows, and jackdaws. The general predators of their eggs are gulls and ravens. The best chance for adult razorbill to avoid predation is by diving. Arctic foxes and polar bears can also predate significant numbers of adults, eggs, and chicks in some years in the north of the species' range. [46]

Razorbill eggs were collected until the late 1920s in Scotland's remote St Kilda islands by their men scaling the cliffs. The eggs were buried in St Kilda peat ash to be eaten through the cold, northern winters. The eggs were considered to taste like duck eggs in taste and nourishment. [47]

Conservation and management

Razorbills on Machias Seal Island Migratory Bird Sanctuary BirdsMSI.jpg
Razorbills on Machias Seal Island Migratory Bird Sanctuary

In the early 20th century, razorbills were harvested for eggs, meat, and feathers. This greatly decreased the global population. In the USA, they were finally protected by the 1917 Migratory Bird Treaty Act which reduced hunting. [22] Other threatening interactions include oil pollution which can damage breeding sites. Any damage to breeding sites can reduce possible nest sites and affect the reproduction of the species. Commercial fishing affects populations because razorbills can become tangled in nets. Overfishing also decreases the abundance of razorbill prey and thus affects their survival.

Evolution and prehistoric species

While the razorbill is the only living species, the genus Alca had a much higher diversity in the Pliocene. Some ornithologists also feel it is appropriate to retain the great auk in the genus Alca, instead of Pinguinus. [48] A number of fossil forms have been found:

As far as is known, the genus Alca seems to have evolved in the western North Atlantic or the present-day Caribbean like most other Alcini. Its ancestors would have reached these waters through the still-open Isthmus of Panama during the Miocene. [49]

Related Research Articles

<span class="mw-page-title-main">Great auk</span> Extinct flightless seabird from the North Atlantic

The great auk, also known as the penguin or garefowl, is a species of flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus. It is unrelated to the penguins of the Southern Hemisphere, which were named for their resemblance to this species.

<span class="mw-page-title-main">Puffin</span> One of several species of seabird

Puffins are any of three species of small alcids (auks) in the bird genus Fratercula. These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crevices among rocks or in burrows in the soil. Two species, the tufted puffin and horned puffin, are found in the North Pacific Ocean, while the Atlantic puffin is found in the North Atlantic Ocean.

<span class="mw-page-title-main">Auk</span> Family of birds

Auks or alcids are a group of birds of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The family contains 25 extant or recently extinct species that are divided into 11 genera. Auks are found throughout the Northern Hemisphere.

<span class="mw-page-title-main">Guillemot</span> Species of seabird

Guillemot is the common name for several species of seabird in the Alcidae or auk family, part of the order Charadriiformes. In Europe, the term covers two genera, Uria and Cepphus. In North America the Uria species are called murres and only the Cepphus species are called "guillemots".

<span class="mw-page-title-main">Atlantic puffin</span> Species of seabird

The Atlantic puffin, also known as the common puffin, is a species of seabird in the auk family. It is the only puffin native to the Atlantic Ocean; two related species, the tufted puffin and the horned puffin being found in the northeastern Pacific. The Atlantic puffin breeds in Russia, Iceland, Ireland, Britain, Norway, Greenland, Newfoundland and Labrador, Nova Scotia, and the Faroe Islands, and as far south as Maine in the west and France in the east. It is most commonly found in the Westman Islands, Iceland. Although it has a large population and a wide range, the species has declined rapidly, at least in parts of its range, resulting in it being rated as vulnerable by the IUCN. On land, it has the typical upright stance of an auk. At sea, it swims on the surface and feeds on zooplankton, small fish, and crabs, which it catches by diving underwater, using its wings for propulsion.

<span class="mw-page-title-main">Black guillemot</span> Species of bird

The black guillemot or tystie is a medium-sized seabird of the Alcidae family, native throughout northern Atlantic coasts and eastern North American coasts. It is resident in much of its range, but large populations from the high arctic migrate southwards in winter. The bird can be seen in and around its breeding habitat of rocky shores, cliffs and islands in single or smalls groups of pairs. They feed mainly by diving towards the sea floor feeding on fish, crustaceans or other benthic invertebrates. They are listed on the IUCN red list as a species of least concern.

<span class="mw-page-title-main">Pigeon guillemot</span> Seabird in the auk family from North Pacific coastal waters

The pigeon guillemot is a species of bird in the auk family, Alcidae. One of three species in the genus Cepphus, it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guillemot; all subspecies, when in breeding plumage, are dark brown with a black iridescent sheen and a distinctive wing patch broken by a brown-black wedge. Its non-breeding plumage has mottled grey and black upperparts and white underparts. The long bill is black, as are the claws. The legs, feet, and inside of the mouth are red. It closely resembles the black guillemot, which is slightly smaller and lacks the dark wing wedge present in the pigeon guillemot.

<span class="mw-page-title-main">Common murre</span> Species of bird

The common murre or common guillemot is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.

<span class="mw-page-title-main">Little auk</span> Species of bird

The little auk (Europe) or dovekieAlle alle is a small auk, the only member of the genus Alle. Alle is the Sami name of the long-tailed duck; it is onomatopoeic and imitates the call of the drake duck. Linnaeus was not particularly familiar with the winter plumages of either the auk or the duck, and appears to have confused the two species. Other old names include rotch, rotche, bullbird, and sea dove, although the latter sometimes refers to a relative, the black guillemot.

<span class="mw-page-title-main">Thick-billed murre</span> Species of bird

The thick-billed murre or Brünnich's guillemot is a bird in the auk family (Alcidae). This bird is named after the Danish zoologist Morten Thrane Brünnich. The very deeply black North Pacific subspecies Uria lomvia arra is also called Pallas' murre after its describer.

<span class="mw-page-title-main">Black-legged kittiwake</span> Species of bird

The black-legged kittiwake is a seabird species in the gull family Laridae. This species was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae as Larus tridactylus. The English name is derived from its call, a shrill 'kittee-wa-aaake, kitte-wa-aaake'. In North America, this species is known as the black-legged kittiwake to differentiate it from the red-legged kittiwake, but in Europe, where it is the only member of the genus, it is often known just as kittiwake.

<span class="mw-page-title-main">Parakeet auklet</span> Species of bird

The parakeet auklet is a small seabird of the North Pacific. Parakeet Auklets used to be placed on its own in the genus Cyclorrhynchus but recent morphological and genetic evidence suggest it should be placed in the genus Aethia, making them closely related to crested auklets and least auklets. It is associated with the boreal waters of Alaska, Kamchatka and Siberia. It breeds on the cliffs, slopes and boulder fields of offshore islands, generally moving south during the winter.

<span class="mw-page-title-main">Rhinoceros auklet</span> Species of seabird related to puffins

The rhinoceros auklet is a seabird and a close relative of the puffins. It is the only extant species of the genus Cerorhinca. Given its close relationship with the puffins, the common name rhinoceros puffin has been proposed for the species.

<i>Cepphus</i> Genus of birds

Cepphus is a genus of seabirds in the auk family also referred to as true guillemots or, in North America, simply as guillemots. The genus name Cepphus is from Ancient Greek κέπφος kepphos, a pale waterbird mentioned by Greek authors including Aristotle. The English word "guillemot" is from French guillemot probably derived from Guillaume, "William". "Murre" is of uncertain origins but may imitate the call of the common guillemot.

<span class="mw-page-title-main">Crested auklet</span> Species of bird

The crested auklet is a small seabird of the family Alcidae, distributed throughout the northern Pacific and the Bering Sea. The species feeds by diving in deep waters, eating krill and a variety of small marine animals. It nests in dense colonies of up to 1 million individuals in the Bering Sea and the Sea of Okhotsk. It often breeds in mixed-species colonies with the least auklet, a smaller congener.

<span class="mw-page-title-main">Fowlsheugh</span>

Fowlsheugh is a coastal nature reserve in Kincardineshire, northeast Scotland, known for its 70-metre-high (230 ft) cliff formations and habitat supporting prolific seabird nesting colonies. Designated as a Site of Special Scientific Interest (SSSI) by Scottish Natural Heritage, the property is owned by the Royal Society for the Protection of Birds. Fowlsheugh can be accessed by a public clifftop trail, or by boats which usually emanate from the nearby harbour at the town of Stonehaven. Tens of thousands of pelagic birds return to the site every spring to breed, after wintering at sea or in more southern climates, principal species being puffins, razorbills, kittiwakes, fulmars and guillemots.

<i>Uria</i> Genus of birds

Uria is a genus of seabirds in the auk family known in Europe as guillemots, in most of North America as murres, and in Newfoundland and Labrador as turr. These are medium-sized birds with mainly brown or black plumage in the breeding season. They breed on the coasts of the northern Atlantic and Pacific oceans.

<i>Pinguinus alfrednewtoni</i> Extinct species of bird

Pinguinus alfrednewtoni is an extinct species of auk related to the great auk known from fossils that were discovered in the Pliocene Yorktown Formation of North Carolina. Like the great auk, it was a large flightless diving bird that used its wings to propel itself forward underwater. Only a limited amount of material is known, despite the rich diversity of fossil auks recovered from the Yorktown Formation. Due to this, it has been proposed that it was either a more coastal animal or simply not as common in more southern waters. This later suggestion could be supported by the discovery of relatively young P. alfrednewtoni remains, indicating that they may have overwintered in the region. One early hypothesis proposed that it was a direct ancestor to the great auk, but this idea is no longer supported. Instead, it is thought that it filled the same niche as its eastern relative, which eventually expanded into the western Atlantic after the extinction of P. alfrednewtoni.

<span class="mw-page-title-main">Seabird breeding behavior</span>

The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the following orders: Procellariiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes. Many seabirds remain at sea for several consecutive years at a time, without ever seeing land. Breeding is the central purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses; this is in stark contrast with passerine birds. Seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the reproductive cycle that are not extensively reported outside of the primary scientific literature.

The cognitive ecology of individual recognition has been studied in many species, especially in primates or other mammalian species that exhibit complex social behaviours, but comparatively little research has been done on colonial birds. Colonial birds live in dense colonies in which many individuals interact with each other daily. For colonial birds, being able to identify and recognize individuals can be a crucial skill.

References

  1. 1 2 3 4 BirdLife International (17 August 2021). "Alca torda (Razorbill)". IUCN Red List of Threatened Species . 17 August 2021: e.T22694852A228697220. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22694852A228697220.en . Retrieved 18 April 2024.
  2. ↑ BirdLife International (18 December 2020). "Alca torda (Razorbill)". IUCN Red List of Threatened Species . 18 December 2020: e.T22694852A166289520. doi: 10.2305/IUCN.UK.2021-3.RLTS.T22694852A166289520.en . Retrieved 18 April 2024.
  3. ↑ Gill F, D Donsker & P Rasmussen (Eds). 2020. IOC World Bird List (v10.2). doi : 10.14344/IOC.ML.10.2.
  4. ↑ Moum, Truls; Arnason, Ulfur; Árnason, Einar (2002). "Mitochondrial DNA sequence evolution and phylogeny of the Atlantic Alcidae, including the extinct Great Auk (Pinguinus impennis)". Molecular Biology and Evolution. 19 (9). Oxford: Oxford University Press: 1434–1439. doi:10.1093/oxfordjournals.molbev.a004206. PMID   12200471.
  5. ↑ Lockwood, William Burley (1984). The Oxford Dictionary of British Bird Names. Oxford: Oxford University Press. ISBN   0-19-214155-4.
  6. ↑ American Ornithologists' Union (1931), A Check-List of North American Birds (4th ed.), Lancaster, PA: Lancaster Press, p. 144
  7. ↑ Proceedings of the Society of Antiquaries of Scotland, Volume 13 (Edinburgh: Society of Antiquaries of Scotland, 1879), ISBN   9781248434567
  8. ↑ Lavers, Jennifer; Hipfner, J. Mark; Chapdelaine, Gilles (28 October 2009). "Razorbill - Introduction - Birds of North America Online". Birds of the World. doi:10.2173/bow.razorb.01. S2CID   216173366 . Retrieved 6 September 2018.
  9. ↑ Leopold, Mardik (January 2004). "The Tricolor oil spill: Characteristics of seabirds found oiled in the Netherlands".
  10. ↑ BirdLife International (1 May 2009). "Alca torda (Razorbill)". IUCN Red List of Threatened Species . 1 May 2009: e.T22694852A23088501. Archived from the original on 19 August 2023. Retrieved 18 April 2024.
  11. ↑ BirdLife International (1 October 2015). "Alca torda (Razorbill)". IUCN Red List of Threatened Species . 1 October 2015: e.T22694852A82978388. doi: 10.2305/IUCN.UK.2015-4.RLTS.T22694852A82978388.en . Archived from the original on 18 April 2024. Retrieved 18 April 2024.
  12. 1 2 Linnaeus, Carl (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1 (10th ed.). Holmiae (Stockholm): Laurentii Salvii. p. 130.
  13. ↑ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  39, 388. ISBN   978-1-4081-2501-4.
  14. 1 2 3 del Hoyo, Josep; Elliott, Andrew; Sargatal, Jordi, eds. (1996). Handbook of the Birds of the World. Volume 3, Hoatzin to Auks. Barcelona: Lynx Edicions. p. 711. ISBN   84-87334-20-2.
  15. ↑ Clusius, Carolus (1605). Exoticorum libri decem. Lugdunum Batavorum [Leiden]: Ex Officinâ Plantinianâ Raphelengii. p. 367.
  16. ↑ Willughby, Francis (1676). Ornithologiae libri tres (in Latin). London: John Martyn. p. 243.
  17. 1 2 Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2021). "Noddies, gulls, terns, skimmers, skuas, auks". IOC World Bird List Version 11.2. International Ornithologists' Union. Retrieved 16 August 2021.
  18. ↑ Friesen, V.L.; Baker, A.J.; Piatt, J.F. (1996). "Phylogenetic relationships within the Alcidae (Charadriiformes: Aves) inferred using total molecular evidence". Molecular Biology and Evolution. 13 (2): 359–367. doi: 10.1093/oxfordjournals.molbev.a025595 . PMID   8587501.
  19. ↑ Linnaeus, C. (1766). Systema Naturæ per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Volume 1 (in Latin). Vol. 1 (12th ed.). Holmiae:Laurentii Salvii. p. 210.
  20. ↑ Storer, Robert W. (1947). "Publications Reviewed" (PDF). Condor. 49: 91. doi:10.2307/1364125. JSTOR   1364125 . Retrieved 11 September 2024.
  21. ↑ "Razorbill Fact Sheet". Lincoln Park Zoo. Archived from the original on 29 September 2011.
  22. 1 2 3 4 5 Conder, P.J. (1950). "On the courtship and social displays of three species of auk". British Birds. 43: 65–69.
  23. ↑ Gaston, Anthony J.; Jones, Ian L. (1998). The Auks: Alcidae. Bird Families of the World. New York: Oxford University Press. pp. 126–132. ISBN   978-0198540328.
  24. ↑ Lavers, J.L.; Jones, I.L.; Diamond, A.W.; Robertson, G.J. (2008). "Annual survival of North American Razorbills (Alca torda) varies with ocean climate indices". Canadian Journal of Zoology. 86 (1). NRC Research Press: 51–61. doi:10.1139/Z07-113.
  25. ↑ McCarthy, Michael (10 July 2008). "Seabird Born in Summer of Love Still Breeding in Wales". The Independent. London. Retrieved 10 July 2008.
  26. ↑ Buckingham, Lila; Bogdanova, Maria I.; Green, Jonathan A.; Dunn, Ruth E.; Wanless, Sarah; Bennett, Sophie; Bevan, Richard M.; Call, Andrew; Canham, Michael; Corse, Colin J.; Harris, Michael P.; Heward, Christopher J.; Jardine, David C.; Lennon, Jim; Parnaby, David; Redfern, Chris P. F.; Scott, Liz; Swann, Robert L.; Ward, Robin M.; Weston, Ewan D.; Furness, Robert W.; Daunt, Francis (17 February 2022). "Interspecific variation in non-breeding aggregation: a multi-colony tracking study of two sympatric seabirds". Marine Ecology Progress Series. 684: 181–197. Bibcode:2022MEPS..684..181B. doi: 10.3354/meps13960 . ISSN   0171-8630. S2CID   244752949.
  27. ↑ Lavers, J.L.; Hipfner, M.J.; Chapdelaine, G.C. (2009). The Birds of North America. Vol. 16. Philadelphia, PA: The Birds of North America, Inc.
  28. 1 2 Lilliendahl, K.; Solmundsson, J.; Gudmundsson, G.A.; Taylor, L. (2003). "Can surveillance radar be used to monitor the foraging distribution of colonially breeding alcids?". Condor (in English and Spanish). 105 (1): 145–150. doi: 10.1650/0010-5422(2003)105[145:CSRBUT]2.0.CO;2 . S2CID   29136400.
  29. ↑ "Fåglarna". Stora Karlsö (in Swedish). Retrieved 11 September 2024.
  30. ↑ Mould, Andy, ed. (2023). Birds in Northumbria 2022. Newcastle upon Tyne: Northumberland and Tyneside Bird Club. p. 110. ISBN   978-1-9993398-5-2.
  31. ↑ Clarkson, K.; Aitken, D.; Cope, R.; O'Hara, D. (2023). Flamborough & Filey Coast SPA: 2022 seabird colony count and population trends (PDF). p. 30. Retrieved 11 September 2024.
  32. ↑ Chapdelaine, G.; Diamond, A.W.; Elliot, R.D.; Robertson, G.J. (2001). Status and population trends of the Razorbill in eastern North America (Report). Occasional Paper. Canadian Wildlife Service.
  33. ↑ "La Liste rouge des espèces menacées en France" (PDF) (in French). UICN Comité Français. p. 6. Archived from the original (PDF) on 26 February 2015. Retrieved 11 September 2024.
  34. ↑ "Razorbill=29 December 2022". audubon.
  35. 1 2 Wagner, R.H. (1991). "Evidence that female Razorbills control extra pair copulations". Behaviour. 118 (3/4). BRILL: 157–169. doi:10.1163/156853991X00265. JSTOR   4534962.
  36. ↑ Wagner, R.H. (1992). "Confidence of paternity and parental effort in razorbills". The Auk. 109 (3). American Ornithologists' Union: 556–562. JSTOR   4088369.
  37. ↑ Plumb, W.J. (1965). "Observations on the breeding biology of the Razorbill" (PDF). British Birds. 58 (11): 449–456. Archived from the original (PDF) on 16 July 2015. Retrieved 14 September 2014.
  38. ↑ Harris, M.P.; Wanless, S. (1989). "The breeding biology of Razorbills Alca torda on the Isle of May". Bird Study. 36 (2): 105–114. doi:10.1080/00063658909477012.
  39. 1 2 Lavers, J.L.; Jones, I.L. (2007). "Factors affecting rates of intraspecific kleptoparasitism and breeding success of the Razorbill at the Gannet Islands, Labrador" (PDF). Marine Ornithology. 35 (1): 1–7.
  40. ↑ Williams, A.J. (1971). "Laying and nest-building behavior in the larger auks (Aves, Alcidae)". Astarte. 4: 61–67.
  41. 1 2 Snow, D. W. (1994). The Birds of the Western Palearctic. Oxford University Press. ISBN   0-19-850187-0.
  42. ↑ Ralph, C. John; Hunt Jr., George L.; Raphael, Martin G.; Piatt, John F., eds. (1995). Ecology and Conservation of the Marbled Murrelet (Report). Vol. PSW-152. Albany, California: USDA Forest Service.
  43. ↑ Dunn, Ruth E.; Wanless, Sarah; Green, Jonathan A.; Harris, Michael P.; Daunt, Francis (2019). "Effects of body size, sex, parental care and moult strategies on auk diving behaviour outside the breeding season". Journal of Avian Biology. 50 (7). doi: 10.1111/jav.02012 . ISSN   1600-048X. S2CID   164436494.
  44. ↑ Piatt, J.F.; Nettleship, D.N. (1985). "Diving depths of four alcids". The Auk. 102 (2): 293–297. doi:10.2307/4086771. JSTOR   4086771.
  45. 1 2 Thaxter, Chris B.; Daunt, Francis; Hamer, Keith C.; Watanuki, Yutaka; Harris, Mike P.; Grémillet, David; Peters, Gerrit; Wanless, Sarah (2009). "Sex-specific food provisioning in a monomorphic seabird, the common guillemot Uria aalge: nest defence, foraging efficiency or parental effort?". Journal of Avian Biology. 40 (1): 75–84. doi:10.1111/j.1600-048x.2008.04507.x.
  46. ↑ Lavers, J.L.; Jones, I.L.; Robertson, G.J.; Diamond, A.W. (2009). "Contrasting population trends at two Razorbill colonies in Atlantic Canada: additive effects of fox predation and hunting mortality?". Avian Conservation and Ecology. 4 (2): 3–17. doi: 10.5751/ACE-00322-040203 .
  47. ↑ The Daily Mail April 18 1930: article by Susan Rachel Ferguson
  48. ↑ Fuller, Errol (1999). The Great Auk (Illustrated ed.). Southborough, Kent, UK: Privately Published. p. 401. ISBN   0-9533553-0-6.
  49. ↑ Bédard, J. (1985). "Evolution and characteristics of the Atlantic Alcidae". In Nettleship, David N.; Birkhead, Tim R. (eds.). The Atlantic Alcidae. London: Academic Press. pp. 6–19. ISBN   0-12-515671-5.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.