Rough-Legged Buzzard Life Cycle: Nest Building To Fledging (and everything in between)

The Rough-Legged Buzzard is a winter visitor to the UK with varying numbers of juvenile birds arriving in October and leaving for their northern breeding grounds in April. These medium to large birds of prey breed in the tundra and taiga regions of North America and Eurasia.

Northern European birds migrate south to warmer areas of Europe and Asia to over winter. It’s at this point that birdwatchers can sometimes spot the odd Rough-Legged Buzzard. Depending on how plentiful their food supply was in their breeding grounds, we could see anywhere from 10 to 150 Rough-Legged Buzzards in the UK during the winter months.

The largest reported influx in recent years was in 1974 when an estimated 250 flew in during October. Since then an average of around 100 arrived in 2010 whereas in 2016 only 34 were spotted. These larger influxes tend to occur around every 6 to 8 years so keep a lookout.

In an average year there are often less than 15 reported confirmed sightings. To find out more about these interesting birds of prey, keep reading.

How Long Does A Rough-Legged Buzzard Live?

The average lifespan of a Rough-Legged Buzzard in the wild is around 19 years. However, there have been individual birds that have lived far longer with one individual reaching an age of 38 years.

Those Rough-Legged Buzzards kept in zoos often live to around 25+ years. This is mainly due to the availability of a steady and constant food supply and favourable conditions.

How Fast Can A Rough-Legged Buzzard Fly?

The Rough-Legged Buzzard flies at a relatively slow speed compared to other raptors. It has a slow and graceful flight with a typical speed of around 30 to 40 mph (48 to 64 km/h).

When diving or stooping on prey it can reach faster speeds but is not known for high-speed chases like many other birds of prey.

Are Rough-Legged Buzzards Aggressive?

Even though Rough-Legged Buzzards are often attacked by Skuas and Gyrfalcons, they are not  a strongly territorial bird. Having said that, they can be aggressive towards Common Buzzards in Sweden with both species trying to keep each other off of their hunting range.

Rough-Legged Buzzards are generally calm and docile birds and often choose to fly away from any potential threats rather than confront them. Even when hunting, they do not enter into aggressive pursuits after their prey as is the manner of some other raptors.

During the breeding season they are known to become more territorial and will often become aggressive towards any intruders including humans that get too close to their nesting sites.

What Is A Rough-Legged Buzzard’s Habitat?

The Rough-Legged Buzzard breeds in tundra and taiga habitats of North America and Eurasia. During winter months when they migrate to warmer climes further south, Rough-Legged Buzzards prefer marshes, prairie and agricultural areas where they can readily find rodent prey.

These medium to large birds of prey prefer open ground; they have a territory of around 4 to 6 square miles during the winter. It’s in this large expanse that they hunt for food.

How Long Does It Take For A Rough-Legged Buzzard To Build A Nest?

It takes Rough-Legged Buzzards around 7 to 14 days to build a nest. With both the male and female taking part in the construction process. They both gather twigs, sticks and other vegetation which is made into a large bulky nest.

The nest is then lined with softer materials like grass, moss, lichen and feathers. Nests have an average overall size of around 2 to 3 feet (0.6 to 0.9 metres) in diameter and a depth of up to 2 feet (0.6 metres).

The nest is typically constructed on cliffs, steep slopes or tall trees in remote areas of tundra, taiga or boreal forests. Their preferred site will have a wide view of the surrounding area.

Rough-Legged Buzzards tend to start constructing their nests as soon as they arrive at their breeding grounds in their Arctic or Subarctic areas.

Eggs

Once the pair are happy with the construction of the nest, they will move on to the next stage in the reproductive cycle, the eggs.

When Do Rough-Legged Buzzards Lay Eggs?

The female Rough-Legged Buzzard typically lays her eggs in May but the timing is dependent on when they arrive back at their breeding grounds and the abundance of food available.

How Many Eggs Does A Rough-Legged Buzzard Lay?

Female Rough-Legged Buzzards can lay between 1 to 7 eggs depending on the age and health of the bird. However, a typical clutch is around 3 to 5.

In years when their prey is in really short supply, Rough-Legged Buzzards may lay fewer eggs or even skip breeding altogether.

What Do Rough-Legged Buzzard Eggs Look Like?

The eggs of the Rough-Legged Buzzard are a creamy-white colour with brown blotches. The eggs are around 55 x 44 mm in size and weigh around 60 grams with 8% of that weight made up by the shell.

Rough-Legged Buzzards only raise 1 brood of eggs per season.

How Long Do Rough-Legged Buzzard Eggs Take To Hatch?

The eggs are incubated solely by the female for around 31 to 33 days. During this time, the male will provide the female with food which he finds in the area around the nesting site.

This is why they select nesting sites with a good wide view of the area so that he can find food for himself and his mate easily.

Chicks

Once the incubation period ends we move on to the next stage in the life cycle of the Rough-Legged Buzzard, the chicks.

How Many Chicks Does A Rough-Legged Buzzard Have?

The number of chicks that a Rough-Legged Buzzard has should correspond with the number of eggs laid. However, the eggs have a 45 to 77% chance of surviving to the hatchling stage.

This means an average clutch of 5 eggs might only see 2 to 4 chicks hatch successfully.

When Do Rough-Legged Buzzard Chicks Open Their Eyes?

When they hatch, Rough-Legged Buzzard chicks are covered in white downy feathers but with their eyes closed. These altricial birds are completely helpless and rely on their parents for food, temperature regulation and protection.

They typically open their eyes anywhere between 4 to 6 days after hatching. Their parents take turns hunting for food and bringing it back to the nest which is then fed to the growing chicks.

When Do Rough-Legged Buzzard Chicks Fledge?

When the chicks get to about 35 to 40 days of age they start to flap their wings and hop around the nest. They will typically fledge the nest at around 45 to 50 days after hatching.

Even though they become fledglings, the young chicks are still not fully independent and will continue to rely on their parents for food and advice. It’s not until around 10 to 12 weeks after fledging that the young chicks will finally become fully independent and leave the breeding grounds.

SEE ALSO: Water Rail Diet and Size: Feeding Habits, Predators, and Measurements

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