Long-Tailed Skua Life Cycle: Nest Building To Fledging (and everything in between)
The Long-Tailed Skua (Stercorarius longicaudus) is a remarkable seabird that captivates birdwatchers and researchers alike with its elegant appearance and impressive migratory journeys.
As the smallest member of the skua family, these birds are known for their exceptional tail streamers, which can account for almost 30 cm of their total length!
In this article, we’ll have a closer look into the life cycle of the Long-Tailed Skua, from nest building to fledging, and their breeding habits and the challenges they face in their Arctic homes.
Table of Contents
How Long Does A Long-Tailed Skua Live?
Long-Tailed Skuas typically live for about 8 to 15 years in the wild. However, some individuals have been known to live longer, with records of birds reaching up to 18 years of age!
Their lifespan is influenced by various factors, including predation, environmental conditions, and food availability. The harsh Arctic breeding grounds and long migratory journeys can pose significant challenges to their survival.
Despite these challenges, Long-Tailed Skuas have evolved to be well-adapted to their environment. Their ability to switch between terrestrial and marine food sources helps them survive in different habitats throughout the year.
How Fast Can A Long-Tailed Skua Fly?
Long-Tailed Skuas are capable of flying at speeds of up to 25 to 31 miles per hour (40 to 50 km/h) during normal flight. However, when pursuing prey or evading predators, they can reach higher speeds for short bursts.
These birds are known for their agile and graceful flight. Their long, pointed wings and streamlined body shape allow them to manoeuvre efficiently in the air. During migration, they can cover vast distances, flying from the Arctic to their wintering grounds in a matter of weeks.
Interestingly, Long-Tailed Skuas are also capable of hovering like helicopters over their breeding territories. This ability allows them to survey their surroundings and spot potential prey or threats.
Are Long-Tailed Skuas Aggressive?
Long-Tailed Skuas can display aggressive behaviour, particularly during the breeding season, but they are generally less aggressive than other skua species.
During the breeding season, Long-Tailed Skuas become territorial and will defend their nesting areas from intruders. They may engage in aerial chases and loud vocalisations to ward off potential threats.
Outside of the breeding season, Long-Tailed Skuas are less aggressive. They are often seen in small groups during migration and in their wintering grounds, where they focus more on feeding than territorial disputes.
What Is A Long-Tailed Skua’s Habitat?
Long-Tailed Skuas have a diverse habitat range that changes with the seasons. During the breeding season, they inhabit the high Arctic tundra, preferring open, treeless areas with low vegetation.
These breeding grounds are typically found in coastal areas or near inland water bodies. The tundra provides them with nesting sites and access to their terrestrial prey, which includes small mammals like lemmings and voles.
Outside of the breeding season, Long-Tailed Skuas become pelagic, spending most of their time at sea. They can be found in offshore and coastal waters, particularly in areas with high productivity where they can find abundant fish and marine invertebrates.
During migration, they can be observed passing through various coastal and inland areas. In the UK, they are seen as passage migrants, typically in May-June and August-October.
How Long Does It Take For A Long-Tailed Skua To Build A Nest?
Long-Tailed Skuas typically take about 2 to 5 days to build their nests. The nest construction is a relatively simple process compared to many other bird species.
The nest is usually a shallow scrape on the ground, often on a slightly raised area to provide a good vantage point. Both male and female participate in nest building, taking turns to scrape out a depression in the tundra vegetation.
The scrape is then lined with moss, lichen, and grass, creating a soft bed for the eggs. Sometimes, they may add a few feathers to the lining. The simplicity of the nest allows for quick construction, which is advantageous in the short Arctic breeding season.
Eggs
The egg-laying process is a crucial stage in the Long-Tailed Skua’s life cycle. Let’s explore the details of their eggs and laying habits.
When Do Long-Tailed Skuas Lay Eggs?
Long-Tailed Skuas typically lay their eggs in late May to early June. The exact timing can vary depending on the latitude of their breeding grounds and the local environmental conditions.
The egg-laying coincides with the short Arctic summer when food is most abundant. This timing is crucial for the survival of the chicks, ensuring they have enough time to grow and develop before the harsh Arctic winter sets in.
How Many Eggs Does A Long-Tailed Skua Lay?
A Long-Tailed Skua usually lays 1 to 2 eggs per clutch.
The number of eggs laid can be influenced by factors such as the age and health of the female, as well as the availability of food in their breeding territory. In years when food is scarce, they may lay fewer eggs or forgo breeding altogether.
What Do Long-Tailed Skua Eggs Look Like?
Long-Tailed Skua eggs are olive-green to brown in colour, with dark brown or black spots. This colouration provides excellent camouflage against the tundra vegetation, helping to protect the eggs from predators.
The eggs are oval in shape and relatively large compared to the size of the bird. They typically measure about 55 to 59 mm in length and 39 to 42 mm in width.
The shell of the egg is smooth but not glossy, which is typical for ground-nesting birds. This matte finish helps to further camouflage the eggs by reducing reflections that might catch a predator’s eye.
How Long Do Long-Tailed Skua Eggs Take To Hatch?
Long-Tailed Skua eggs typically take about 23 to 26 days to hatch. Both parents share incubation duties, taking turns to sit on the eggs while the other forages for food.
The incubation period is relatively long for a bird of this size, which is common among Arctic-breeding species. This extended incubation allows for fuller development of the chicks before hatching, preparing them for the harsh Arctic environment they’ll face.
Chicks
The development of Long-Tailed Skua chicks from hatching to fledging is a fascinating process, marked by rapid growth and increasing independence.
How Many Chicks Does A Long-Tailed Skua Have?
A Long-Tailed Skua pair typically raises 1 to 2 chicks per breeding season. This corresponds to the number of eggs laid, although not all eggs may hatch successfully, and not all chicks may survive to fledging.
In years with abundant food, both chicks in a two-egg clutch may survive. However, in years with scarce resources, it’s common for only one chick to survive, usually the first-hatched, which has a size and strength advantage.
The small number of offspring allows the parents to invest more resources in each chick, increasing their chances of survival in the challenging Arctic environment.
When Do Long-Tailed Skua Chicks Open Their Eyes?
Long-Tailed Skua chicks open their eyes very soon after hatching, typically within the first day. This quick development is an adaptation to the short Arctic summer, allowing the chicks to become alert to their surroundings rapidly.
At hatching, the chicks are covered in down and are relatively well-developed compared to many other bird species. This precocial nature helps them survive in the challenging Arctic environment.
When Do Long-Tailed Skua Chicks Fledge?
Long-Tailed Skua chicks usually fledge (develop flight feathers and leave the nest) at about 25 to 30 days after hatching. However, they remain dependent on their parents for food and protection for several weeks after fledging.
The fledging period is a critical time for the young skuas. They must quickly learn to fly and forage effectively before the short Arctic summer comes to an end. Parents continue to feed and defend their fledglings during this time, gradually encouraging more independence.
By late August or early September, the young birds are usually ready to begin their first migration south, an incredible journey for birds just a few months old.
SEE ALSO: Long-Tailed Skua Vs Little Tern: Key Differences Explained
Frequently Asked Questions
Long-Tailed Skuas primarily feed on small mammals, such as lemmings, during the breeding season. At sea, they consume small fish, carrion, and offal.
The best time to spot Long-Tailed Skuas in the UK is during their migration periods, specifically in May, June, August, and September.
Currently, Long-Tailed Skuas are not classified as endangered, but they are considered vulnerable to changes in their Arctic breeding habitat due to climate change.
