Scaup Life Cycle: Nest Building To Fledging (and everything in between)
Scaups are amongst the rarest breeding ducks in the UK with only around 1 to 5 pairs actually breeding here every year. From a distance, the male Scaup, when in his breeding plumage, looks like a black and white duck. But when seen up close, male Scaups have an iridescent green shine to their heads with a thin black barring pattern on their backs, a bluish bill and a striking yellow eye.
Females tend to be brown with dark brown heads and distinctive white patches next to the bill. When the male isn’t in breeding plumage he has a mottled grey body and a blackish head. When Scaups are in flight they show white stripes along the back edge of their wings.
To find out much more about Scaups, keep reading.
Table of Contents
How Long Does A Scaup Live?
The Scaup, also known as the Greater Scaup or “Bluebill” in North America, is a diving duck. In the wild they have an average lifespan of around 3 years and typically start breeding at the age of 2 years.
However many Scaup have survived in the wild to reach an age of around 10 to 15 years according to ring records. The oldest ever recorded Scaup was more than 20 years of age.
How Fast Can A Scaup Fly?
The Scaups that overwinter in the UK breed primarily in Iceland and the northern coasts of the Baltic sea and even as far north as the Arctic Sea in Russia. These birds can fly at speeds of around 75 mph (121 km/h).
They are a popular game bird in Europe and North America and are hunted for sport. They are hunted using shotguns because they must be shot as they fly. Their fast flight speed makes hunting them challenging.
Although many Scaup get shot and killed during the hunting season every year, they have a worldwide population of around 1,200,000 to 1,400,000 adult birds.
Are Scaups Aggressive?
For the most part Scaups are relatively social birds who will readily join in with large mixed species foraging groups after the breeding season has finished. During the breeding season however, they can display aggressive behaviour especially with other members of their species.
They will also show aggressive behaviour towards any perceived intruders into their nesting sites.
What Is A Scaup’s Habitat?
Scaup can be observed foraging for food on lakes, rivers, estuaries and salt bays during the breeding season. During the spring and summer they can be seen on lakes and bogs in quite open landscapes and up as far as the edges of boreal forests and tundra regions.
During winter, they migrate southwards into areas which are more exposed like coastal bays, estuaries and lagoons. They are often observed at inland lake sites during the winter period.
How Long Does It Take For A Scaup To Build A Nest?
It can take anywhere between 7 to 14 days for a Scaup nest to be constructed. The female selects the most suitable site and constructs the nest. She forms a shallow scrape in the ground which is lined with soft vegetation and feathers.
The siting of the nest is typically in dense vegetation often in grasses and sedge close to bodies of water. In some cases, she will use a small island or floating platform to build the nest.
Eggs
Once she is satisfied with the construction of the nest, the female will lay her eggs.
When Do Scaups Lay Eggs?
The exact timing of the egg laying depends on geographical location and can be any time from mid May to early July. The eggs will not be laid until the climatic conditions are favourable and able to support the incubation and chick rearing stage of the reproductive cycle.
How Many Eggs Does A Scaup Lay?
The pair will only raise one brood per season and the female can lay anywhere between 8 to 11 eggs. However a typical clutch contains between 6 to 9 eggs.
The number of eggs laid depends on the age and health of the female with healthier, more experienced females laying more eggs with a higher survival rate of eggs to chicks.
What Do Scaup Eggs Look Like?
Scaup eggs are olive or light buff in colour with some slight pitting on the surface. They are typically plain and unmarked by any blemishes or spots.
The eggs typically measure around 62 x 43 mm in size with an average weight of around 67 grams.
How Long Do Scaup Eggs Take To Hatch?
The female undertakes incubating the eggs by herself for around 23 to 28 days. She doesn’t start incubating the eggs until after the last egg has been laid.
Chicks
Once the eggs hatch, we move on to the next stage in the life cycle of the Scaup, the chick rearing stage.
How Many Chicks Does A Scaup Have?
In some cases, the number of chicks corresponds to the number of eggs laid. However, this isn’t always the case as Scaup eggs have around a 60 to 70% survival rate to the hatchling stage.
Factors that can affect the survival rate of the eggs to chicks include, fertilisation or the lack of, predation and adverse weather conditions. This means that from a clutch of 9 eggs you can expect around 6 chicks to successfully reach the hatchling stage.
When Do Scaup Chicks Open Their Eyes?
Scaup chicks are precocial which means they hatch with their eyes open and covered in downy feathers. They typically leave the nest for the first time within 24 hours of hatching.
They follow their mother down to the water where they feed themselves. She will protect them from predators and show them where to find food.
When Do Scaup Chicks Fledge?
The chicks stay with their mother for the first few weeks of their lives. All the time growing and developing strong flight muscles and flight feathers.
They will not have the ability to fly until they are around 40 to 45 days old. At this point they fly or fledge for the first time.
SEE ALSO: Whooper Swan Diet and Size: Feeding Habits, Predators, and Measurements
Frequently Asked Questions
The average lifespan of the Scaup or “Greater Scaup” as it is known in North America is around 3 years in the wild although some birds have lived for as long as 10 or even 15 years according to ring records.
Scaup eggs are olive or light buff in colour with slight pitting to the surface. The eggs are unmarked by any blotches or spots and around 62 x 43 mm in size.
The average flight speed of a Scaup is around 75 mph (121 km/h).
