Black guillemot
A circumpolar seabird of northern Atlantic and Arctic coasts.
The black guillemot, also called the tystie (Cepphus grylle), is a seabird of medium size belonging to the auk family. It lives along the northern Atlantic coasts and the eastern shores of North America. While it stays put in many parts of its range, large groups from the high Arctic head south for the winter. The IUCN lists it as a species of least concern.
In summer, both males and females look alike: black feathers all over, with a big white patch on the upper side of each wing. Their bill is black, long, and slender, and their feet are a bright coral-red. Come winter, the underparts turn white, the upperparts become pale grey, and the back and shoulders show a barred pattern of light grey and white. They breed in solitary pairs or small groups, starting between late February and early May. Nests are placed above the high tide mark, usually in cliff crevices or gaps between boulders—many pairs just lay their eggs directly on the ground without building a proper nest. A typical clutch has two eggs, which are dull white to pale green with bold dark spots and blotches. Both parents take turns incubating for 28 to 32 days. After hatching, the chicks are covered in black down and are cared for by both parents until they fledge at 30 to 40 days old, leaving the nest on their own. Once they fledge, the chicks are completely independent and usually return to their birth colony at three or four years old.
The black guillemot was first formally described by Carl Linnaeus in 1758 in his *Systema Naturae*, where he placed it in the genus *Alca* and named it *Alca grylle*. He gave its type locality as the Ocean of northern Europe, later narrowed to Sweden. Today it is one of three species in the genus *Cepphus*, introduced by Peter Pallas in 1769. The genus name comes from the Ancient Greek *kepphos*, a pale waterbird mentioned by Aristotle and others. The species name *grylle* is the local dialect name for the bird on Gotland, used when Linnaeus visited in 1741. The English word "guillemot" comes from French *guillemot*, likely from *Guillaume* ("William"), but ultimately imitates the loud, high-pitched "will, willem" begging calls of young common guillemots. Five subspecies are recognized: *C. g. mandtii* (high Arctic coasts from Greenland to Alaska and Canada), *C. g. arcticus* (low Arctic to north temperate coasts, including southern Greenland, the British Isles
- Scientific name
- Cepphus grylle
- Length
- 30–32 cm
- Wingspan
- 52–58 cm
- Weight
- 300–460 g
- IUCN status
- Least concern
- Number of subspecies
- 5
Lore & Background
The black guillemot was formally described in 1758 by Carl Linnaeus in the tenth edition of Systema Naturae, who placed it in the genus Alca with the binomial name Alca grylle. The species is now one of three in the genus Cepphus, introduced by Peter Pallas in 1769. The genus name Cepphus derives from Ancient Greek kepphos, a pale waterbird mentioned by Aristotle, while the species name grylle was the local Gotland dialect name for the bird at the time of Linnaeus's visit in 1741. Five subspecies are recognized, ranging from high Arctic coasts to the Baltic Sea.
Both sexes have very similar appearances: black plumage with a large white patch on the upper side of the wings in summer, a black bill, and coral-red feet. In winter, adults have white underparts and pale grey upperparts with barred light grey and white patterning. Juveniles and immatures can be identified by spotting on the white wing patch. The call in the breeding season is a high whistle, and the red gape is prominent then.
Black guillemots breed in solitary pairs or small groups, nesting above the high tide mark in cliff crevices or gaps in boulders, often laying directly on the ground. They typically lay 2-egg clutches, with incubation by both parents lasting 28 to 32 days. Chicks fledge at 30–40 days and become totally independent, beginning to re-join their natal colony at age three or four years.
Reader's Guide
The black guillemot is a significant species for understanding Arctic and subarctic marine ecosystems. As a coastal forager that dives to depths of at least 43 meters, it preys on benthic and kelp-forest species such as sculpins, butterfish, rock gunnel, northern sandlance, herring, jellyfish, mollusks, and small crustaceans. Its foraging behavior—single-prey loading and diving using wings for propulsion and feet for steering—illustrates adaptations to inshore feeding. The species faces threats from predators including American mink, great skua, gulls, Eurasian otter, brown rat, and feral cats; one large Baltic colony was wiped out by American mink in the early 2000s. Pollution, fisheries bycatch, habitat destruction, and climate change add pressure. Approximately 40% of the population breeds in the high Arctic, 30% in the low Arctic, and 30% in boreal waters. The bird is one of the few to breed on Surtsey, Iceland, a new volcanic island. Its presence across a wide latitudinal range and its sensitivity to environmental changes make it a useful indicator species for monitoring the health of northern coastal habitats.
Did You Know?
- The black guillemot is also known as the tystie.
- It is one of the few birds to breed on Surtsey, Iceland, a new volcanic island.
- Both parents incubate the eggs for 28 to 32 days.
- The species name grylle was the local Gotland dialect name for the bird at the time of Linnaeus's visit in 1741.
Frequently Asked Questions
Who is Black guillemot?
The Black guillemot (Cepphus grylle), nicknamed the tystie, is a medium-sized seabird in the auk family that calls the northern Atlantic and Arctic coasts home. It stands about 30–32 cm long with a 52–58 cm wingspan and tips the scale at roughly 300–460 grams.
What does Black guillemot look like?
In its summer plumage both sexes are jet-black with a bold white panel on the upper wing, a long slender black bill, and vividly coral-red feet. As winter arrives the underparts fade to a paler tone, softening the otherwise stark black-and-white contrast.
Where does Black guillemot live and does it migrate?
This circumpolar species spans northern Atlantic shores and the eastern coastline of North America, split into five recognized subspecies. Populations in milder parts of the range tend to stay put, while large flocks from the high Arctic make a seasonal push southward for the colder months.
What role does Black guillemot play in its ecosystem?
As a proficient coastal diver, it plucks small fish and marine invertebrates from rocky waters, linking benthic prey to higher predators in Arctic and sub-Arctic food webs. Its nesting colonies on sea cliffs also make it a key indicator of coastal ecosystem health.
What is Black guillemot's conservation status?
The IUCN currently lists the species as Least Concern, reflecting its broad circumpolar distribution and stable populations. No immediate extinction risk is identified, though ongoing coastal development and climate shifts remain areas of watch.
More in Birds of the Arctic 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record