Name: Black Guillemot, Guillemot à Miroir, Tystie (Cepphus grylle)
Length: 30 cm.
Weight: 320 to 480 grams.
Location: Arctic coastlines.
Conservation status: Least Concern.
Diet: Fish, crustaceans, marine invertebrates.
Appearance: Black body with black bill, white patch on wings, red feet. During winter colouring turns to a white base with a darker back.
How do Black Guillemots feed?
Black Guillemots are divers, diving in relatively shallow waters, using its wings to swim. They can stay under for about 21/2 minutes. Smaller prey will be swallowed while still underwater, but larger prey, held crosswise in the bill, will be brought to the surface.
Are Black Guillemots social?
Outside of mating season Black Guillemots are generally found solo or in a pair. They will however come together over feeding areas.
How fast do Black Guillemots fly?
Black Guillemots generally fly at speeds of about 20 km per hour.
What are Black Guillemot birthing rituals like?
Black Guillemots reach sexual maturity at 4 years.
They breed in colonies that get denser the further north one goes where food is more available. The more populous colonies can number up to 10,000 breeding pairs.
They create their nests on rocky coastlines. The nests, which can be made up of pebbles, shells, seaweed, or nothing at all are usually placed amongst rocks that provide some sort of overhanging “roof”.
In order to woo a female the male will stand up as tall as he can with his bill pointing downward and then strut around the female with exaggerated steps.
Up to 2 eggs are laid. Both parents take turns incubating the eggs for about a month while the other forages. Once hatched, both parents will alternate taking care of the chick with going off to feed, returning with fish for the hatchling.
The chicks will leave the nest from 1 to 2 months after hatching, heading down to the water where they will take care of themselves until they learn to fly.
How long do Black Guillemots live?
Black Guillemots live for about 11 years in the wild.
How many Black Guillemots are there today?
There are an estimated 400,000 to 700,000 individual Black Guillemots in the world today.
Do Black Guillemots have any natural predators?
Black Guillemot young and eggs are prey to rats, foxes, and minks.
7 Bountiful Black Guillemot Facts
- Black Guillemots are a member of the Alcidae family (or Auks) such as the Puffin.
- Some Black Guillemots show a preference over which direction they hold a fish in their bills. Nobody is exactly sure why, but some biologists think it may be related to their preferred feeding ground.
- The colourisation of the winter plumage gets whiter the further north a particular individual Black Guillemot is found.
- Black Guillemots are one of the only types of bird that breeds on Surtsey, a new volcanic island off of Iceland.
- There are five subspecies of Black Guillemot:
1. Cepphus grylle arcticus – Northeast U.S.A., southeast Canada, Greenland, Britain, Scandinavia, White Sea
2. Cepphus grylle faroeensis – Faroe Islands
3. Cepphus grylle grylle – Baltic Sea
4. Cepphus grylle islandicus – Iceland
5. Cepphus grylle mandtii – Northeast Canada, Svalbard, Siberia, Alaska
- Birds like the Black Guillemots that use diving pursuits to catch prey are generally only found in colder regions because the warmer the water gets the faster fish can swim (their speed doubles in a range where waters go from 5 degrees Celsius to 15 degrees), but the birds stay at the same swimming speed.
- Black Guillemots found further out in deeper waters tend to be non-breeding.