Great Skua Diet and Size: Feeding Habits, Predators, and Measurements
The great skua is known by many different names including the pirate of the sea and “Bonxie”. They get the name the pirate of the sea because of the aggressive way they steal food from other birds.
“Bonxie” is an old Norse word meaning dumpy and describes the size and shape of the bird. The great skua is a frequent visitor to the Scottish islands during the breeding season which starts in May.
They also breed in the Faroe Islands, Norway and Iceland. Keep reading to find out more about these interesting seabirds.
Table of Contents
The Dietary Habits Of The Great Skua
Let’s start by looking into what food the great skua eats and what they feed their chicks.
What Does A Great Skua Eat?
The great skua is a large gull-like seabird that has a reputation for stealing food from other birds. They soar up into the air and then swoop down in an aggressive manner to intimidate other birds into giving up their food.
This can be freshly caught fish or regurgitated food that is expelled in order to fly away as fast as possible to escape the threat posed by the great skua.
The great skua is known to eat fish, birds, eggs, dead animals and birds and they will even take small rodents and rabbits as food when the need arises. If there are no other sources of food, great skuas will also eat berries.
There have been several reports of great skuas following fishing boats and stealing fish and or fish offal.
What To Feed A Baby Great Skua?
The chicks are fed on regurgitated food including fish, small birds, small mammals, carrion, eggs and chicks from neighbouring nests left unattended.
The chicks are precocial which means they are born with their eyes open and they can leave the nest at around the age of 2 days. They stay with their parents who feed them and teach them how to hunt for food until the chicks reach around 40 to 50 days of age when they fledge and leave the nest.
Breeding Habits Of Great Skuas
Great skuas reach sexual maturity at around the age of 7 or 8 and fly inland to find a partner. The males put on great shows of posturing with other males to attract a female.
This posturing involves lots of wing flapping to show their bright white wing flashes. Once they find a mate, the pair fly off and form a scrape nest which is lined with local vegetation.
The female typically lays 2 eggs which are incubated by both parents for around 28 to 32 days. Once the eggs hatch the chicks stay with their parents for around 40 to 50 days before leaving the nest and their parents and flying out to sea.
Do Great Skuas Mate For Life?
Great skuas are known to stay with the same partner for all of their lives. They typically return to their original breeding ground year after year to raise their next brood.
As they live for an average of around 34 years, they will return to the same breeding ground for around 26 years in total. The rest of the year the great skua will be out at sea and only return to land to breed.
The Size & Weight Of Great Skuas
Now let’s have a look at the average size and weight of the great skua.
How Much Does A Great Skua Weigh?
Females tend to be larger than males (by around 5%) with an average weight of around 1.2 to 2 kg. This is the same weight as an average osprey or 1 to 2 bags of sugar.
Great skuas are easily distinguishable from other seabirds by their robust, chunky build.
How Big Is A Great Skua?
The average length of a great skua is around 53 to 58 cm which is a similar length as the curlew.
They have a wingspan of between 125 to 140 cm which is similar to that of the snowy owl. The great skua uses its large wings to soar high into the air before swooping at great speeds of up to 50 mph to intimidate other birds to give up their food.
Are Great Skuas Under Threat?
According to the Birds of Conservation Concern, the great skua is classified as amber and like all birds in the UK they are protected under the Wildlife and Countryside Act 1981.
However, it was reported in 2023 that the avian flu epidemic affected large numbers of these magnificent seabirds. It has been reported by the RSPB (Royal Society for the Protection of Birds) that more than ¾ of the population of great skuas were found dead in Scotland.
Scotland is home to around 60% of the world’s population of great skuas so this loss is significant.
What Eats A Great Skua?
Great skuas are more vulnerable to predatory attacks when nesting in their breeding grounds. Young chicks and eggs can be taken by foxes, cats and other predatory mammals.
In some areas polar bears have been known to take chicks and eggs from great skua nests.
Where Can I See Great Skuas In The UK?
Great skuas can be seen in the UK in the north of Scotland and on the Shetland and Orkney islands. From mid March to mid July where around 90% of the breeding population can be found.
They can also sometimes be seen along the coasts offshore of the North sea. So along the East coast of Scotland and England on their way to their winter sites off the coast of Spain and Africa.
SEE ALSO: Arctic Skua Vs Great Skua: Key Differences Explained
Frequently Asked Questions
The diet of the great skua consists mainly of fish, small birds, small mammals and offal. However, they will eat berries if there are no other sources of food available.
Although great skuas are quite large seabirds known for their intimidating behaviour to obtain food, they do become prey to other inhabitants of their habitat. These predators include foxes, cats and in some cases, polar bears.
According to the RSPB, the biggest threat to the great skua population is avian flu which has reportedly reduced the population by around ¾ in 2023.
Great skuas are carnivores and scavengers but they will supplement their diets with berries when there’s nothing else to eat.
