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Overview

Brief Summary

Razorbills are expert swimmers and divers. Their short wings work just as well above water as under water. Diving down to 120 meter in search of lesser sandeel or other fish is no problem. In the air, they are true acrobats. They can flap their wings so quickly that you can't even follow it with the naked eye. This rapid wing movement allows them to fly low over the water surface and navigate between the waves.
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Biology

Breeding colonies form in spring; each pair has a single brood consisting of one egg each year (1). The egg is laid in a crevice or hole, or a nest of pebbles (1). The young leave the breeding colony while still unfledged, at around 18 days after hatching and are looked after by the parents for some time (7). In winter, the diet is known to consist mainly of fish such as herring, whiting and sand eel, although crustaceans and worms are also eaten (4). Patterns of movement are complex, but it seems that birds in their first year travel further distances than adults (4).
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Description

This handsome bird has a characteristic deep, flattened (1), wedge-shaped (3) bill, which is black in colour with a white line. The underparts are white, and the black upperparts are darker than those of the similar guillemot (Uria aalge). Juveniles in their first winter have smaller and more pointed bills, which lack the white line seen in adults (1). This species is not particularly vocal, but a deep creaking 'urrr' is produced by breeding individuals (1). In Cornwall, an alternative common name for the razorbill is 'murre', which is probably imitative of this call (3). The scientific name Alca is thought to derive from the Icelandic word for this bird, Alka, which is thought to imitate another call of the razorbill, a harsh 'arrc-arrc' (3).
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Distribution

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)

Biogeographic Regions: arctic ocean (Native ); atlantic ocean (Native )

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Range Description

Their breeding habitat is islands, rocky shores and cliffs on northern Atlantic coasts, in eastern North America as far south as Maine (USA), and in western Europe from northwestern Russia to northern France. North American birds migrate offshore and south, ranging from the Grand Banks of Newfoundland (Canada) to New England (USA). Eurasian birds also winter at sea, with some moving south as far as the western Mediterranean.
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occurs (regularly, as a native taxon) in multiple nations

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National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: Hudson Strait and western Greenland south to Gulf of Maine, and from Iceland, Jan Mayen, Bjornoya and northwestern Russia south to Brittany and the Baltic Sea. In the early 1980s, nested on four islands in Gulf of Maine (Maine, the only U.S. breeding sites) (Spendelow and Patton 1988). WINTERS: mostly offshore in northern boreal waters south to Long Island (New York), Azores, western Mediterranean (AOU 1983).

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North America; range extends from Greenland to North Carolina
  • North-West Atlantic Ocean species (NWARMS)
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North Atlantic, south to New York, England and Northwestern Europe sometimes south to Mediterranean.
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Range

Occurs in the North Atlantic; Britain is a stronghold (4). This species breeds in internationally important numbers around the British coast. In combination, British and Irish totals represent around 20% of the world population (1).
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Physical Description

Morphology

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)

Range mass: 505 to 730 g.

Range wingspan: 182 to 210 mm.

Other Physical Features: endothermic ; bilateral symmetry

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Size

Length: 43 cm

Weight: 719 grams

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Length: 40-45 cm, Wingspan: 63-66 cm
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Ecology

Habitat

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)

Habitat Regions: saltwater or marine

Aquatic Biomes: coastal

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Habitat and Ecology

Habitat and Ecology
Behaviour Razorbills are pursuit divers that propel themselves through the water with their wings. They are capable of diving to 120m depth, but mostly forage nearer the surface. They spend most of their lives at sea, only arriving ashore to reproduce. During the prelaying period, they never spend a night in the nest, and even after the egg is laid, only one parent remains in the nest. Diet They are known to consume krill, amongst other prey. In the Bay of Fundy, Canada, 76% of Razorbill stomachs contained krill (Huettman et al 2005). Foraging range This species has been described as coastal rather than pelagic (Huettman et al 2005), and birds tend to be concentrated within 10 km of the shore (BirdLife International 2000, Huettman et al 2005). At Flamborough Head, UK, maximum densities of birds were observed at under 1 km from the colony and 6 - 28 km away from the colony (BirdLife International 2000). Birds were seen up to 25 km from the Pembrokeshire Islands in 1992, with the highest mean density within 5 km, whereas in June 1990, birds were found up to 45 km away (albeit in low numbers beyond 25km) with the highest densities within 10 km (BirdLife International 2000). At the Isle of May during chick rearing, radio-tracking revealed that 91% of birds foraged at over 10 km from the colony, although transect counts showed a density maximum within 5 km of the colony (Wanless et al. 1998). Another area of high bird density was located 35km away over the Wee Bankie (Wanless et al. 1998). Razorbills breeding at St Kilda foraged at the Whale Rock Bank, 38 km away, although a high proportion of the breeding population appeared to be foraging within 5 km of the island. At North Rona the maximum feeding range was 15 km. Razorbills are probably capable of diving to at least 120 m. Analysis of surveys of distribution at sea indicated that very few were present in waters deeper than 200 m during the breeding season, with the greatest abundance found at depths less than 100 m. At the Isle of May, they foraged preferentially in shallow waters (less than 30 m deep) (Wanless et al. 1998). The same individuals used several widely-separated feeding areas on different days and even on the same day (Wanless et al. 1998). Razorbills occur in high numbers around fronts, as around the Irish Sea Front during autumn. On the Isle of May they were found to be associated with both tidal fronts and the presence of the Clyde front during the early breeding season (BirdLife International 2000). They were also highly concentrated at an offshore bank near St Kilda (Leaper et al. 1988, BirdLife International 2000). In winter in the Bay of Fundy, Canada, they tended to forage within tidal upwelling zones (Huettman et al 2005). A significant proportion of Razorbills breeding in North America spend at least part of the winter in the outer Bay of Fundy and in its coastal zone (i.e. less than 8km offshore) (Huettman et al 2005). It is likely that, in winter, the species gathers in relatively small areas where predictable concentrations of prey occur (Huettman et al 2005).

Systems
  • Terrestrial
  • Marine
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Comments: Sea coasts and open sea. Nests on coastal cliffs and on rocky shores and islands, usually in crevice or niche or in holes between and under boulders (AOU 1983, Harrison 1978). Usually nests with murres (Terres 1980). Usually uses same nest site in successive years. Isolated islands free of quadruped predators seem essential for successful reproduction (Buckley and Buckley 1984).

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Depth range based on 34019 specimens in 1 taxon.
Water temperature and chemistry ranges based on 14894 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): -0.858 - 24.405
  Nitrate (umol/L): 0.348 - 16.868
  Salinity (PPS): 5.715 - 35.801
  Oxygen (ml/l): 4.763 - 8.711
  Phosphate (umol/l): 0.142 - 0.890
  Silicate (umol/l): 0.565 - 12.889

Graphical representation

Temperature range (°C): -0.858 - 24.405

Nitrate (umol/L): 0.348 - 16.868

Salinity (PPS): 5.715 - 35.801

Oxygen (ml/l): 4.763 - 8.711

Phosphate (umol/l): 0.142 - 0.890

Silicate (umol/l): 0.565 - 12.889
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

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Open sea and cliffs.
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Inhabits both coastal and oceanic waters (2), and breeds on coastal cliffs and rock stacks in summer (2).
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Stellwagen Bank Pelagic Community

 

The species associated with this page are major players in the pelagic ecosystem of the Stellwagen Bank National Marine Sanctuary. Stellwagen Bank is an undersea gravel and sand deposit stretching between Cape Cod and Cape Ann off the coast of Massachussets. Protected since 1993 as the region’s first National Marine Sanctuary, the bank is known primarily for whale-watching and commercial fishing of cod, lobster, hake, and other species (Eldredge 1993). 

Massachusetts Bay, and Stellwagen Bank in particular, show a marked concentration of biodiversity in comparison to the broader coastal North Atlantic. This diversity is supported from the bottom of the food chain. The pattern of currents and bathymetry in the area support high levels of phytoplankton productivity, which in turn support dense populations of schooling fish such as sand lance, herring, and mackerel, all important prey for larger fish, mammals, and seabirds (NOAA 2010). Sightings of many species of whales and seabirds are best predicted by spatial and temporal distribution of prey species (Jiang et al 2007; NOAA 2010), providing support for the theory that the region’s diversity is productivity-driven.

Stellwagen Bank is utilized as a significant migration stopover point for many species of shorebird. Summer visitors include Wilson’s storm-petrel, shearwaters, Arctic terns, and red phalaropes, while winter visitors include black-legged kittiwakes, great cormorants, Atlantic puffins, and razorbills. Various cormorants and gulls, the common murre, and the common eider all form significant breeding colonies in the sanctuary as well (NOAA 2010). The community of locally-breeding birds in particular is adversely affected by human activity. As land use along the shore changes and fishing activity increases, the prevalence of garbage and detritus favors gulls, especially herring and black-backed gulls. As gull survivorship increases, gulls begin to dominate competition for nesting sites, to the detriment of other species (NOAA 2010). 

In addition to various other cetaceans and pinnipeds, the world’s only remaining population of North Atlantic right whales summers in the Stellwagen Bank sanctuary. Right whales and other baleen whales feed on the abundant copepods and phytoplankton of the region, while toothed whales, pinnipeds, and belugas feed on fish and cephalopods (NOAA 2010). The greatest direct threats to cetaceans in the sanctuary are entanglement with fishing gear and death by vessel strikes (NOAA 2010), but a growing body of evidence suggests that noise pollution harms marine mammals by masking their acoustic communication and damaging their hearing (Clark et al 2009).

General threats to the ecosystem as a whole include overfishing and environmental contaminants. Fishing pressure in the Gulf of Maine area has three negative effects. First and most obviously, it reduces the abundance of fish species, harming both the fish and all organisms dependent on the fish as food sources. Secondly, human preference for large fish disproportionately damages the resilience of fish populations, as large females produce more abundant, higher quality eggs than small females. Third, by preferentially catching large fish, humans have exerted an intense selective pressure on food fish species for smaller body size. This extreme selective pressure has caused a selective sweep, diminishing the variation in gene pools of many commercial fisheries (NOAA 2010). While the waters of the SBNMS are significantly cleaner than Massachusetts Bay as a whole, elevated levels of PCBs have been measured in cetaceans and seabird eggs (NOAA 2010). Additionally, iron and copper leaching from the contaminated sediments of Boston Harbor occasionally reach the preserve (Li et al 2010). 


  • Clark CW, Ellison WT, Southall BL, Hatch L, Van Parijs SM, Frankel A, Ponirakis D. 2009. Acoustic masking in marine ecosystems: intuitions, analysis and implication. Inter-Research Marine Ecology Progress Series 395:201-222.
  • Eldredge, Maureen. 1993. Stellwagen Bank: New England’s first sanctuary. Oceanus 36:72.
  • Jiang M, Brown MW, Turner JT, Kenney RD, Mayo CA, Zhang Z, Zhou M. Springtime transport and retention of Calanus finmarchicus in Massachusetts and Cape Cod Bays, USA, and implications for right whale foraging. Marine Ecology 349:183-197.
  • Li L, Pala F, Mingshun J, Krahforst C, Wallace G. 2010. Three-dimensional modeling of Cu and Pb distributions in Boston Harbor, Massachusetts and Cape Cod Bays. Estuarine Coastal & Shelf Science. 88:450-463.
  • National Oceanographic & Atmospheric Administration. 2010. Stellwagen Bank National Marine Sanctary Final Management Plan and Environmental Assessment. “Section IV: Resource States” pp. 51-143. http://stellwagen.noaa.gov/management/fmp/pdfs/sbnms_fmp2010_lo.pdf
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Migration

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Arrives in southern breeding areas (Maine) near end of February (Cowger 1976). Birds breeding in Labrador and Greenland migrate to Newfoundland and farther south (Brown 1985).

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Moves offshore to southern part of range in winter.
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Trophic Strategy

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)

Primary Diet: carnivore (Piscivore )

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Comments: Winter adult diet off Newfoundland mainly crustaceans, mainly fishes in Baltic. Summer adult diet in Labrador: capelin, sculpins, euphausiids. In southeastern Canada, chicks are fed fishes (mainly sandlance and capelin). Dives to at least 120 m (Piatt and Nettleship 1985).

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Mostly fish, will also consume marine worms and crustaceans.
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Associations

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

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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)

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Population Biology

Number of Occurrences

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 300

Comments: Many small colonies, but a major portion of the global population (over 200,000) nest in one large colony at western tip of Iceland.

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Global Abundance

>1,000,000 individuals

Comments: World population was estimated at about 700,000 pairs by Nettleship and Evans (1985). Censuses during the 1970s and early 1980s yielded about 15,000 pairs breeding in Canada/New England. See Evans (1984) for population data from Greenland.

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General Ecology

Annual adult survival in each of several areas was > 80%; usually 89% or more (Hudson 1985).

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Life History and Behavior

Behavior

Perception Channels: visual ; tactile ; acoustic ; chemical

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Life Cycle

Razorbill chicks hatch at a weight of about 60g, and weight is directly correlated with egg size. They spend about 18 days at the breeding site. Chicks leave the colony around 18-23 days after hatching. By that time they are only partly grown and still flightless. They weigh between 140g and 180g when they leave the colony. (Wagner, 1999)

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Life Expectancy

Range lifespan

Status: wild:
29.4 (high) years.

Average lifespan

Status: wild:
88 months.

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Lifespan, longevity, and ageing

Maximum longevity: 30.4 years (wild)
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Reproduction

Egg-laying for Razorbills start in the first week of May and laying continues until the first week of June. At higher latitudes, or where water temperatures are lower, laying is later. A female Razorbill can produce only one egg each season. Most breeding sites are enclosed or partially enclosed to protect the egg from predators. The single egg is usually laid directly on bare rock, but some parents would collect small stones, dried dropping, lichen or other bits of vegetation from the immediate surrounding area and place them where the egg will be laid. (Nettleship & Birkhead, 1985)

Before laying their eggs, at least half of the females leave their mates and sneak off to another ledge to copulate with other males. Then they come back and copulate with their mates on an average of 80 times in the 30 days before the laying of the first egg. Later, while their mates are safely occupied incubating their eggs, the females slip away again to the neighboring ledge for more copulation. The couplings are like auditions to see who is better and are probably important in pair formation. (Carely, 1993)

Range eggs per season: 1 (high) .

Average eggs per season: 1.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous

Average time to hatching: 36 days.

Average eggs per season: 1.

Incubation for some happens immediately after laying. Parents exchange incubation duty several times a day. After the chick hatched the parents would feed the chick with fish up to 20 fish at a time, but they usually bring one to six fish at a meal. (Nettleship & Birkhead, 1985)

Parental Investment: male parental care ; female parental care

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Eggs are laid in May in Maine, June where seas are colder. Clutch size is 1. Incubation, by both sexes, averages 35-37 days. Single young is tended by both sexes, leaves for sea at average age of 17-19 days, tended by male for several weeks. In Wales, first breeds at 4-5 years.

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First breeds at 4-5 years old. May mate for life. Nesting colonies on cliffs and rocky coastline. 1 egg, incubated by both sexes for 32-39 days. Young fed whole food by both parents.
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Molecular Biology and Genetics

Molecular Biology

Barcode data: Alca torda

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 11 barcode sequences available from BOLD and GenBank.

Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.

See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

GGCACCCTGTATCTGATCTTTGGCGCATGAGCCGGCATAGTTGGTACTGCCCTA---AGCCTACTTATCCGCGCAGAACTAGGCCAACCAGGGACCCTCCTAGGAGAC---GACCAAATCTACAACGTAATCGTCACCGCCCATGCCTTCGTAATAATCTTCTTCATAGTTATGCCAATCATAATCGGCGGCTTCGGAAACTGATTAGTCCCACTTATA---ATCGGTGCACCCGACATAGCATTTCCTCGCATAAACAATATAAGCTTCTGACTACTACCCCCATCATTCTTACTCCTTCTAGCCTCATCTACAGTAGAAGCTGGAGCTGGTACAGGATGAACTGTTTACCCTCCCCTAGCTGGCAACCTAGCCCATGCCGGAGCTTCAGTAGATCTA---GCAATCTTCTCTCTCCACTTAGCAGGTGTATCCTCCATCCTAGGTGCTATCAACTTTATCACAACAGCCATCAATATAAAACCCCCAGCCCTTTCACAGTACCAAACCCCATTATTCGTATGATCAGTACTTATCACTGCTGTCTTACTACTTCTCTCACTTCCAGTACTCGCCGCT---GGCATTACCATGCTACTAACAGACCGAAACCTAAACACCACATTCTTCGATCCAGCCGGAGGCGGCGATCCAGTACTATACCAACACCTCTTCTGATTCTTCGGCCACCCAGAAGTATATATCCTAATTCTACCAGGTTTCGGAATTATCTCTCACGTCGTAACGTACTATGCAGGAAAAAAA---GAACCATTCGGATACATAGGAATAGTATGAGCTATACTATCCATCGGCTTCCTAGGCTTCATCGTATGAGCCCATCACATATTTACCGTAGGAATAGATGTGGATACCCGAGCCTACTTCACATCTGCCACTATAATCATTGCTATTCCTACTGGCATCAAAGTATTTAGCTGACTA---GCCACA
-- end --

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Statistics of barcoding coverage: Alca torda

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 11
Specimens with Barcodes: 12
Species With Barcodes: 1
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Conservation

Conservation Status

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)

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

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IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2012

Assessor/s
BirdLife International

Reviewer/s
Butchart, S. & Symes, A.

Contributor/s

Justification
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
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National NatureServe Conservation Status

Canada

Rounded National Status Rank: N4B,N4N : N4B: Apparently Secure - Breeding, N4N: Apparently Secure - Nonbreeding

United States

Rounded National Status Rank: N1B - Critically Imperiled

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NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Reasons: Widely distributed, although the bulk of the world population breeds in a few colonies in Iceland. Despite historic declines, global population thought to be stable or increasing at present.

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Status in Egypt

Accidental visitor.

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No official conservation status.
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Status

Receives general protection under the Wildlife and Countryside Act (2). Included in the Birds of Conservation Concern Amber List (medium conservation concern) (6).
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Population

Population Trend
Increasing
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Global Short Term Trend: Relatively stable (=10% change)

Comments: Thought to be stable or increasing throughout major parts of range (Hipfner and Chapdelaine 2002). Hyslop and Kennedy (1992) indicated population increases in most areas of the Gulf of St. Lawrence and estuary between the 1970s and 1990. Populations increased in the Gulf of St. Lawrence region in the 1980s according to Chapdelaine and Brousseau (1992). Recolonization continues in Gulf of Maine as population increases (Podolsky 1989, Mawhinney and Sears 1996).

Global Long Term Trend: Decline of 30-70%

Comments: Hunting, egging and persecution have caused marked reductions in populations, but there have been no large-scale changes to range over historical period (Hipfner and Chapdelaine 2002). Gulf of St. Lawrence populations have declined over long term (Nettleship and Evans 1985).

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Threats

Comments: Populations in Greenland may be impacted by hunting and salmon netting (Evan 1984). On islands off Labrador, breeding populations were eliminated or reduced by colonizing arctic foxes (Birkhead and Nettleship 1995).

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This species can be very seriously affected by oil pollution, and is particularly vulnerable when dispersing away from the breeding colonies (1). Other types of marine pollution, including heavy metals used in industry and organochloride pesticides used in agriculture are also threats and are known to cause deaths (1). Furthermore, food shortages, which may be caused by over-fishing, are a potentially serious problem (1).
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Management

Management Requirements: See Evans and Nettleship (1985) for management recommendations.

Management Research Needs: See Evans and Nettleship (1985) for research recommendations.

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Conservation

Seabirds, including the razorbill, were among the first bird species given protection by legislation. A number of major seabird colonies are protected by the RSPB and other conservation organisations as nature reserves (8). Research into the ecology of seabirds, and the effects of the industrial fishing of sand eels on their populations is needed (1).
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Relevance to Humans and Ecosystems

Benefits

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)

Positive Impacts: research and education

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Economic Uses

Comments: Hunted on breeding grounds in Greenland (Evans 1984).

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Wikipedia

Razorbill

For other uses, see Razorbill (disambiguation).

The razorbill (Alca torda) is a colonial seabird that only comes to land in order to breed. This agile bird chooses 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. Once the chick has hatched, the parents take turns foraging for their young and sometimes fly long distances before finding prey.

The razorbill is primarily black with a white underside. The male and female are identical in plumage; however, males are generally larger than females. In 1918, the razorbill was protected in the United States by the Migratory Bird Treaty Act. Presently, the major threat for the population is the destruction of breeding sites.[citation needed]

Description[edit]

The razorbill has white underparts and a black head, neck, back and feet during 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 nonbreeding season, the throat and face behind the eye become white, and the white line on the face becomes less prominent.[2] The thick black bill has a blunt end. It is large for an alcid and its mean weight ranges from 505 to 890 g (17.8 to 31.4 oz).[3] The female and male adults are very much alike, having only small differences such as wing length. The wing length of adult males ranges from 201–216 mm (7.9–8.5 in) while that of females ranges from 201 to 213 mm (7.9 to 8.4 in).[4] 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. The razorbill chooses one partner for life, and nests along coastal waters of the continental shelf. 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 89-95%.[5] Though the razorbill's average lifespan is roughly 13 years, a bird ringed in the UK in 1967 has survived for at least 41 years — a record for the species.[6]

Taxonomy[edit]

The razorbill is in the family Alcidae and its genus is Alca. It is closest living relative to the great auk (Pinguinis impennis), which is now extinct. The Alcini clade also includes the common murre (Uria aalge), the thick-billed murre (Uria lomvia) and the dovekie (Alle alle).[7]

There are two subspecies of razorbill recognized by the American Ornithologists' Union. Alca torda torda, named by Linnaeus in 1758, occurs in the Baltic and White Seas, Norway, Bear Island, Iceland, Greenland, and eastern North America. 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 subspecies, 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.

Habitat and distribution[edit]

The world population of razorbills is estimated at about 500,000 to 700,000 breeding pairs.[8] Razorbills thrive in water surface temperature below 15°C. They are often seen with other larger auks, such as the 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 some moving south as far as the western Mediterranean. Approximately 60 to 70% of the entire razorbill population breeds in Iceland.[9]

Razorbill colonies include (north to south):

In flight

Behaviour[edit]

The life history traits of the razorbill are similar to that of the common murre. However, razorbills are slightly more agile. During breeding, both male and female protect the nest. Females select their mate and will often encourage competition between males before choosing a partner.[12] Once a male is chosen, the pair will stay together for life.

Reproduction[edit]

Individuals only breed at 3–5 years of age. 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.[3] 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.[3] The pair will mate up to 80 times in a 30 day period to ensure fertilization.[13] Females will sometimes encourage other males to engage in copulation to guarantee successful fecundity.[12]

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.

Nest sites and location[edit]

Nest site determination is very important for these birds to ensure protection of young from predators. Unlike murres, nest sites are not immediately alongside the sea on open cliff ledges but at least 10 cm (3.9 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.[14]

The mating pair will often reuse the same site every year.[15][16] Since chicks do not have the ability to fly nests close to sea provide easy access when leaving the colony. Generally razorbills do not build a nest; however, some pairs often use their bills to drag material upon which to lay their eggs.[17]

Banded chick on Gannet Island, Labrador

Incubation and hatching[edit]

Females lay a single egg per year. The egg is an ovoid-pyramoidal shape, ground in color and has dark brown blotches. Incubation occurs 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.[18] 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 male parent will accompany the chick to sea.

Feeding[edit]

Razorbills dive deep into the sea using their wings and their streamlined bodies to propel themselves toward their prey. 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 (82 ft) but they have the ability to dive up to 120 m (390 ft) below the surface.[19] 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.[20] 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.[3] Females will generally feed their chicks more frequently than males.[20] They may well fly more than 100 km (62 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 (7.5 mi) away, and often in shallower water.[10]

Diet[edit]

The diet of a razorbill is very similar to that of a common murre. It consists generally of mid water schooling fish such as capelin, sand lance, juvenile cod, sprats and herring. It may also include crustaceans and polychaetes. A recent study suggests the razorbill's diet is affected by local and regional environmental conditions in the marine environment [16]

Predators[edit]

The adult razorbill has several predators which include: polar bears, great black-backed gulls, peregrine falcons, ravens, crows and jackdaws. The general predators of their eggs are gulls and ravens. The best chance for an adult razorbill to avoid predation is by diving. Arctic foxes can also predate significant numbers of adults, eggs, and chicks in some years.[21]

Conservation and management[edit]

In the early 20th century, razorbills were harvested for eggs, meat and feathers. This greatly decreased the global population. In 1917, they were finally protected by the “Migratory Bird Treaty Act” which reduced hunting.[3] Other threatening interactions include oil pollution which can damage breeding sites. Any damage to breeding sites can reduce possible nest sites and affect 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[edit]

With common murres, Runde, Norway.

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.[22] 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.[23]

References[edit]

  1. ^ BirdLife International (2012). "Alca torda". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013. 
  2. ^ "Razorbill Fact Sheet". Lincoln Park Zoo. Archived from the original on 29 September 2011. 
  3. ^ a b c d e Conder, P.J. (1950). "On the courtship and social displays of three species of auk". British Birds 43: 65–69. 
  4. ^ 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. 
  5. ^ 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 (NRC Research Press) 86 (1): 51–61. doi:10.1139/Z07-113. 
  6. ^ McCarthy, Michael (10 July 2008). "Seabird Born in Summer of Love Still Breeding in Wales". The Independent (London). Retrieved 10 July 2008. 
  7. ^ 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: 359–367. doi:10.1093/oxfordjournals.molbev.a025595. 
  8. ^ Lloyd, C.S.; Tasker, M.L.; Partridge, K. (1991). The Status of Seabirds in Britain and Ireland. London: T & A.D. Poyser. ISBN 978-1408138007. 
  9. ^ Lavers, J.L.; Hipfner, M.J.; Chapdelaine, G.C. (2009). The Birds of North America 16 (635). Philadelphia, PA: The Birds of North America, Inc. 
  10. ^ a b 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 with Spanish abstract) 105 (1): 145–150. doi:10.1650/0010-5422(2003)105[145:CSRBUT]2.0.CO;2. 
  11. ^ Chapdelaine, G.; Diamond, A.W.; Elliot, R.D.; Robertson, G.J. (2001). "Status and population trends of the Razorbill in eastern North America". Occasional Paper (105). Canadian Wildlife Service. 
  12. ^ a b Wagner, R.H. (1991). "Evidence that female Razorbills control extra pair copulations". Behaviour (BRILL) 118 (3/4): 157–169. doi:10.1163/156853991X00265. JSTOR 4534962. 
  13. ^ Wagner, R.H. (1992). "Confidence of paternity and parental effort in razorbills". The Auk (American Ornithologists' Union) 109 (3): 556–562. JSTOR 4088369. 
  14. ^ Plumb, W.J. (1965). "Observations on the breeding biology of the Razorbill". British Birds 58 (11): 449–456. 
  15. ^ 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. 
  16. ^ a b Lavers, J.L.; Jones, I.L. (2007). "Factors affecting rates of intraspecific kleptoparasitism and breeding success of the Razorbill at the Gannet Islands, Labrador". Marine Ornithology 35 (1): 1–7. 
  17. ^ Williams, A.J. (1971). "Laying and nest-building behavior in the larger auks (Aves, Alcidae)". Astarte 4: 61–67. 
  18. ^ Ralph, C. John; Hunt, Jr., George L.; Raphael, Martin G. et al., eds. (1995). "Ecology and Conservation of the Marbled Murrelet". PSW-152. Albany, California: USDA Forest Service. 
  19. ^ Piatt, J.F.; Nettleship, D.N. (1985). "Diving depths of four alcids". The Auk 102 (2): 293–297. doi:10.2307/4086771. 
  20. ^ a b 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. 
  21. ^ 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 - Écologie et conservation des oiseaux 4 (2): 3–17. 
  22. ^ Fuller, Errol (1999). The Great Auk (Illustrated ed.). Southborough, Kent, UK: Privately Published. p. 401. ISBN 0-9533553-0-6. 
  23. ^ Bédard, J. (1985). Nettleship, David N.; Birkhead, Tim R., eds. Evolution and characteristics of the Atlantic Alcidae. The Atlantic Alcidae (London: Academic Press). pp. 6–19. ISBN 0-12-515671-5. 
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