Arctic Skua Fact File
The Arctic skua is also known as the Parasitic skua or the Arctic or Parasitic Jaeger. Parasitic comes from their habitat of stealing food from other birds. They will chase other birds which have recently caught food and try to get them to drop it.
They breed in the Arctic region before migrating down South where they will overwinter.
Outside of the breeding season when they are tending their nest they will spend the rest of their time at sea.
Learn more about these brilliant birds by reading on below.
Multiple color phases of the Arctic skua are recognized. One phase has a white belly with a dark back and cap of the head. The dark phase is dusky brown across the body.
Their tail features two forked tips which may be up to 8cm (3in) long. Breeding adults have long tail streamers while non-breeding individuals and juveniles have much smaller streamers.
The feet of an Arctic skua are webbed and tipped with sharp claws. These allow them to grab their food.
An average Arctic skua will measure 37-44cm (14.6-17.3in) long with a weight of 450g (15.9oz) Their wingspan is up to 1.2m (3.9ft) across. Females tend to be larger than males.
The arctic skua is a carnivore. They are known for chasing other birds such as terns and puffins to steal fish they have caught. Arctic skuas will also hunt their own food by flying low across the waves.
During the breeding season they supplement their diet with lemmings and small birds.
Arctic skuas will visit boats to scavenge discarded waste.
Arctic skuas breed in Arctic areas along the coastline of Eurasia and North America. They will then migrate to spend the winter along the southern tip of South America, parts of Africa and along the coast of Australia and New Zealand.
Breeding takes place in tundra habitats. Often they are seen near coasts and large rivers along the edges of grassland and moorlands.
Outside of the breeding season they are only found in the open ocean.
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Breeding takes place from May to September once they have returned from their migration to the southern hemisphere. Breeding tends to begin earlier in the south when compared with the north.
Their breeding site is either used by a single pair or a small group.
Each year a pair of Arctic skuas will return to the same site for breeding. They are monogamous and will retain their mate for life unless a death occurs. Pairs tend to breed every year though when conditions are not ideal they will delay breeding for a year.
Often pairs seem to be formed from one bird of each color morph. Evidence exists to suggest that the pale form of the Arctic skua may eventually be eliminated through sexual selection.
Two eggs are deposited in to a nest where they will be incubated for 25-28 days. Fledging occurs after 25-30 days.
Pairs are highly protective of their nest. When threatened they will dive bomb anything that comes close to the nest.
The first two years of their life are spent at sea before they come to land and breed.
Sexual maturity is reached between three and four years old.
Arctic skuas spend most of their time flying over the ocean and will only come to land when it is time to breed.
Each year they perform a migration from the Arctic to the southern hemisphere. They arrive there in October and November and have left by February or March. Occasionally they may be blown off course and end up in tropical places such as South-East Asia.
Where they live on the coast Arctic skuas will survey their territory from mounds. These are formed on a large object such as bone or rock. Over time they accumulate large amounts of guano and plants will grow in them.
These birds may move around in groups of up to 10 at a time.
Predators and Threats
Natural predators of the Arctic skua include birds such as ravens and great skuas along with American minks.
Arctic skuas are sensitive to fluctuations in the population of sandeels (a group of fish with an eel like appearance). Declines in their stock will cause declines in Skua populations.
In parts of their range their is population control carried out to reduce stress on other species of birds.
Arctic skuas are also known as Arctic or Parasitic Jaegers. Jaeger comes from a German word for hunter reflecting their predatory nature.
The name skua comes from an Old Norse word for gull.
These birds inspired the name of the British Royal Air Force's first dive bomber, the Blackburn skua.
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Jinesh PS, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Donald Macauley from Carshalton, Surrey, UK, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons
Christiansen, P., 2019. Birds. London: Amber Books Ltd.
Wildlifetrusts.org. 2021. Arctic skua | The Wildlife Trusts. [online] Available at: <https://www.wildlifetrusts.org/wildlife-explorer/birds/seabirds/arctic-skua> [Accessed 16 May 2021].
Dakota, A. 2009. "Stercorarius parasiticus" (On-line), Animal Diversity Web. Accessed May 16, 2021 at https://animaldiversity.org/accounts/Stercorarius_parasiticus/
Szabo, M.J. 2013 [updated 2017]. Arctic skua. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz
Scottish Wildlife Trust. 2021. Arctic skua. [online] Available at: <https://scottishwildlifetrust.org.uk/species/arctic-skua/> [Accessed 16 May 2021].
BirdLife International. 2018. Stercorarius parasiticus. The IUCN Red List of Threatened Species 2018: e.T22694245A132535550. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22694245A132535550.en. Downloaded on 16 May 2021.