Ospreys return & eggs arrive....

Ospreys have nested at Cumbria Wildlife Trust’s Foulshaw Moss reserve for the ninth year. Guest blogger and Foulshaw Moss Nature Reserve volunteer Alasdair McKee tells us more...

a foulshaw osprey on nest at Foulshaw Moss Nature Reserve — @ Cumbria Wildlife Trust

The pair returned to Foulshaw Moss Nature Reserve from their winter holiday in west Africa on March 26th 2021. They migrated south last autumn, but several weeks apart, the female osprey going first for a well-earned vacation after a long summer of looking after eggs and chicks.

As far as we know, the ospreys spend the winter apart with no contact until they return to the nest. For them to make a journey of 4000 Km (2500 miles) and arrive not just on the same day, but within a few hours, is quite remarkable.

They get to know each other again with a bit of a ritual. The female osprey spends weeks on the nest incubating eggs and then looking after chicks, she needs to know that she is going to be well fed. She calls loudly at the male to tell him it’s time to prove himself and bring her some grub.

the Foulshaw Ospreys pair land on the nest with a fish — @ Cumbria Wildlife Trust

Ospreys are unusual for birds of prey as they only eat fish, catching them by diving from up to 30m (100 feet) in the air. They plunge into the water, sometimes submerging to a depth of a metre (3 feet) and grab their prey. When they take off again – no easy feat when you are very wet and weighed down with a heavy load – they turn the fish round so it’s carried head first. This is more aerodynamic and keeps the flappy tail out of the way.

The male brings the fish back to Foulshaw Moss Nature Reserve and eats his share in a tree near the nest. He always removes the head, possibly because that’s his favourite bit, but also to ensure the fish won’t flap around in the nest, damaging eggs or chicks.

Foulshaw Osprey female sitting on her first egg laid in the nest in 2021 — @ Cumbria Wildlife Trust

When supper is delivered to the nest, Mrs Osprey doesn’t stand on ceremony and hungrily wrestles it away from him. She’s about 20% bigger than him, so she gets what she wants.

There are, of course, other courtship rituals and they have led to a clutch of three eggs. The first was laid on 10April, then the others after two then another three days. This staggering system creates a pecking order among the chicks that ensures at least some survive if there is a shortage of food.

That’s never been a problem for our skilful anglers and, after about 35 days of incubation, we hope to see the first chick appear on about 15 May.

It will be as welcome to the nest as its returning parents and we shall watch the whole story unfold on our live osprey webcam