As was mentioned above, Black guillemots forage inshore during the breeding season and generally lay 2 eggs. This is typical of other guillemots (Pigeon guillemot, Cepphus columba and Spectacled guillemot, Cepphus carbo) but atypical of most members of the Alcidae family who forage far from shore and produce a single egg. Explanations for this distinctive strategy suggest that the inshore foraging and the double clutch go hand in hand. With Alcids it has been suggested that clutch size is a function of food availability or the ability of adults to provide food for young. Therefore guillemots have developed an inshore foraging strategy during the breeding season giving them easy access to food during chick rearing periods. This may allow them to raise more young than long-distance foraging Alcids. Studies of Black guillemot energy expenditure during chick rearing support this hypothesis (Birkhead and Harris 1985; Mehlum et al. 1993).
Perception Channels: visual ; tactile ; acoustic ; chemical
Black guillemots have no threatened status and are quite abundant, especially in some regions of the high arctic. Total population of the North Atlantic and Arctic oceans was estimated in 1985 at 270,000 pairs (200,000-350,000). In some areas population declines have been observed. In the past local reductions may have resulted from hunting or egging. Currently some populations seem to be increasing and expanding their distributions. Locally introduced predators, oil spills, and commercial gill-net fishing may impact guillemots, however there are no serious threats globally. High rates of nest visits by scientists have also been shown to decrease nesting success (Brown and Nettleship 1984; Cairns 1980; Johnsgard 1987; Nettleship and Evans 1985; Nettleship 1996).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
During the 1800's and first half of the 20th century Black guillemots were taken for food; adults were hunted, young collected and eggs taken from nests. These activities were known to occur in parts of eastern Canada (mainly Labrador and the Gulf of St. Lawrence), Iceland, Faeroe Islands, British Isles, areas of the White Sea, and many Scandinavian countries. Many laws prevent such activities now (Nettleship and Evans 1985).
Like other members of the Alcidae family, C. grylle are adapted to wing-propelled swimming allowing them to dive deeply where they feed mainly on fish on or near the seafloor. Prey items include sandlance (Ammodytidae), gunnels (Pholidae), sculpins (Cottidae), pricklebacks (Stichaeidae), Arctic cod (Boreogadus saida) and many other fish as well as many invertebrates: polychaetes, molluscs, jellyfish, crustaceans, sponges, crabs, and even barnacles. They are known to dive for nearly 2 minutes and up to estimated depths of 50m. Many patterns of foraging behavior have been found. There is typically a morning, and sometimes evening, peak in foraging activity, but in some areas feeding may be continuous throughout daylight hours. Foraging distribution has been shown to change with tidal cycles where birds prefer waters of moderate flow. Seasonal cycles also exist with guillemots feeding inshore during the breeding season and farther offshore or around pack ice edges during the winter (Bradstreet and Brown 1985; Cairns 1986; Cairns 1992; Johnsgard 1987; Nettleship 1996; Nol and Gaskin 1987; Winn 1950).
The Black guillemot is a circumpolar species distributed in boreal, low arctic and high arctic regions of the North Atlantic and Arctic oceans. Black guillemots can be found in coastal areas from the Gulf of Maine, New England across parts of the northern coast of North America, as far as Alaska. In Europe and Asia they are found from the British Isles and northward across the northern coast of Asia. The largest concentrations can be found among islands of the high and low arctic. Wintering populations disperse as far south as Rhode Island in North America and France in the eastern Atlantic (Johnsgard 1987; Nettleship and Evans 1985; Nettleship 1996).
Biogeographic Regions: arctic ocean (Native ); atlantic ocean (Native )
Generally Black guillemots are restricted to rocky shores due to their nesting requirements. They nest most often in crevices among stones and boulders at the base of cliffs or cracks in cliffs, and less often under rocks among vegetation and under driftwood. In the high arctic some cliff sites may be as high as 230m. Artificial cover (debris on shore, harbor walls, under buildings) has allowed guillemots to nest in areas where they may not have previously.
Foraging habitat varies dramatically with the seasons. During the breeding season birds forage in inshore waters generally less than 50m in depth. Although they remain fairly close to shore year round, in winter months black guillemots are more pelagic, frequently feeding along pack ice edges where pack ice occurs. Some overwinter in polynyas of the high north (Brown 1985; Cairns 1992; Harris and Birkhead 1985; Johnsgard 1987; Nettleship 1996; Winn 1950).
Aquatic Biomes: coastal
Average lifespan
Status: wild: 157 months.
A relatively small seabird, Black guillemots are approximately 32cm in length. In breeding plumage, as their name implies, Black guillemots are black from bill to tail. They also have large white wing patches, and bright red feet, legs and inside the mouth. As many as seven sub-species have been described based on variations in size, bill and wing length, and plumage. After an early fall moult adults take on a patchy black and white plumage that has been described as "salt and pepper" and legs become a paler red. This winter plumage retains the white wing patch on the black wing, however the body plumage becomes white below and barred black and white above with a black bill and mostly white head. Newly fledged birds are similar to wintering adults and yearlings have an adult-like plumage with brownish spots in the white wing patch (Bedard 1985; Gaston 1985; Johnsgard 1987; Nettleship 1996; Stokes and Stokes 1996).
Range mass: 325 to 550 g.
Other Physical Features: endothermic ; bilateral symmetry
Black guillemots breed in relatively small scattered colonies and lay 2 eggs. The typical reproductive cycle is as follows. Some adults over-winter near breeding colonies while the others return between late February and early May. Birds have been seen searching for suitable nest sites (see habitat section for nesting requirements) immediately after copulation and eggs are usually laid between late May and mid June. Guillemots have a double brood patch; two eggs are the standard clutch size but sometimes one and more rarely three are laid. More experienced parents often lay slightly earlier and have a larger mean clutch size. Once the last egg is laid incubation is continuous with both parents sharing shifts for 28 to 32 days. Colony attendance is highest in the early morning. Down-covered semi-precocial chicks take 3 to 4 days to fully hatch then are left unattended in the nest. As the chicks get older they wander inside the nest crevice. Both sexes feed the demanding chicks up to 20 fish a day until they fledge at age 30 to 40 days. Sometimes parents must entice young from the nest with fish, but once fledged, chicks are on their own. The average breeding success ranges from 0.48 to 1.6 young per pair with losses due to predation, bad weather, and flooding from high tides. By age three or four, young birds start to breed and join this cycle (Harris and Birkhead 1985; Hilden 1994; Johnsgard 1987; Nettleship 1996; Winn 1950).
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 25 days.
Average eggs per season: 2.
The black guillemot or tystie (Cepphus grylle) 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.
Both sexes have very similar appearances with black plumage and a large white patch on the upper side of their wings in summer. The bill is also black, being rather long and slender, while the feet are coral-red. In winter adult underparts are white and the upperparts are a pale grey with the back and shoulders exhibiting barred light grey and white patterning.
The birds breed in solitary pairs or small groups during their breeding season starting in late February and early May. Breeding pairs will typically lay 2-egg clutches and raise 2 chicks to fledging. Incubation typically lasts 28 to 32 days, once hatched chicks receive care from the parents until they fledge aged 30 – 40 days. Once fledged chicks are totally independent and by age three or four years they will begin to re-join their natal colony.
The genus name Cepphus is from Ancient Greek kepphos, a pale waterbird mentioned by Greek authors including Aristotle. The species name grylle was the local dialect name for this bird in Gotland at the time of Linnaeus's visit there in 1741.[2] The English word "guillemot" is from French guillemot probably derived from Guillaume, "William".[3]
The black guillemot is a medium-sized bird with adults normally 30 to 32 centimetres (12 to 12+1⁄2 inches) in length and with wingspans of 52 to 58 cm (20+1⁄2 to 23 in). The bodyweight can range from 300 to 460 grams (10+1⁄2 to 16 ounces). Adults have both summer and winter plumage and there is no sexual difference in this that can be identified in the field. The English common name “Black Guillemot” references their strikingly black breeding summer plumage which is totally black except for a large white patch on the upper side of their wings. During the summer plumage, their legs, feet and inside of the mouth are all a bright coral-red, and their beak is a black. Adults lose their summer plumage in an early fall moult where their upper plumage become barred with light grey and white, their head is a pale grey, their underparts white, and legs and feet a pale red. They retain their white wing patch, black beak and red inside their mouth. The call in the breeding season is a high whistle. The red gape is also prominent then.
Juveniles and immatures can easily be identified by the spotting of the white wing patch with grey or brown feathers and is easy to see even at far distances in the field.
There are five listed subspecies of the black guillemot:[4]
The black guillemot is a circumpolar species distributed in the boreal, low arctic and high arctic regions of the north Atlantic and arctic oceans and breeding between 43° and 82°N. The 5 listed subspecies inhabit different parts of this range. In North America they can be found as far south as the Gulf of Maine and New England and across parts of the northern coast of North America as far as Alaska, where they are replaced by the pigeon guillemot in the North Pacific. In Europe and Asia they are found from the British Isles and Northward across the northern coast of Asia. They are one of the few birds to breed on Surtsey, Iceland, a new volcanic island. In the UK it is a fairly common breeding bird in western and northern Scotland and Ireland. In the rest of Great Britain they only breed at St. Bees Head in Cumbria, the Isle of Man and on east Anglesey in north Wales. Approximately 40% of the population breeds in the high arctic where the largest colonies are found, 30% in the low arctic, and 30% in boreal waters. In the winter some of the birds in the high arctic waters are forced south by the winter ice making them seasonal migrants, but in more temperate zones the species is essentially resident.
Typically restricted to rocky shores, black guillemots utilize the cliffs, crevices and boulders for their nests, hunting the inshore waters for benthic prey. Compared to other auks they forage fairly close to the colony, in the breeding season mostly in inshore waters more than 50m in depth, farther afield in the winter months.
One of the early ornithologists that described aspects of the behaviour of the black guillemot was Edmund Selous (1857-1934) in his book The Bird Watcher in the Shetlands (1905).[5] In the chapter titled 'From the Edge of a Precipice'[6] he writes for instance that sometimes the black guillemots carry a fish they have caught in their beak for hours. He also gives further details about the behaviour.
They dive for food from the surface, swimming underwater. They mainly eat fish and crustaceans, also some mollusks, insects and plant material.
The black guillemot or tystie (Cepphus grylle) 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.
Both sexes have very similar appearances with black plumage and a large white patch on the upper side of their wings in summer. The bill is also black, being rather long and slender, while the feet are coral-red. In winter adult underparts are white and the upperparts are a pale grey with the back and shoulders exhibiting barred light grey and white patterning.
The birds breed in solitary pairs or small groups during their breeding season starting in late February and early May. Breeding pairs will typically lay 2-egg clutches and raise 2 chicks to fledging. Incubation typically lasts 28 to 32 days, once hatched chicks receive care from the parents until they fledge aged 30 – 40 days. Once fledged chicks are totally independent and by age three or four years they will begin to re-join their natal colony.
The genus name Cepphus is from Ancient Greek kepphos, a pale waterbird mentioned by Greek authors including Aristotle. The species name grylle was the local dialect name for this bird in Gotland at the time of Linnaeus's visit there in 1741. The English word "guillemot" is from French guillemot probably derived from Guillaume, "William".
