FROM HUMBLE BEGINNINGS

Poland is home to tens of thousands of white storks (though numbers there are sadly declining). Many birds are injured flying into electricity transmission cables, pylons and in traffic collisions. A lucky few are rescued and rehabilitated at Warsaw Zoo. Many of these birds have such extensive damage to their wings and flight feathers that, though otherwise perfectly healthy, they’ll never be able to take to the skies again.

In 2016 the White Stork Project, a collaboration with Cotswold Wildlife Park, the Roy Dennis Wildlife Foundation, Knepp Estate and other landowners, were given 34 injured birds by Warsaw Zoo Some of these birds have stayed at Cotswold Wildlife Park where they help educate the public about the threats to storks and produce young every year to be released into the wild from Knepp and Wadhurst Park in East Sussex. And some of the non-flying birds came to Knepp where they were released into a six-acre pen to protect them from foxes and other predators. ‘Stork HQ’ was born. Here, these ground-bound birds would act as a magnet for wild storks prospecting over England from Europe, and hopefully tempt them down to breed and help establish the first wild colony of white storks in Britain for hundreds of years

Every year, a new generation of young birds bred from the Polish non-fliers at Cotswold Wildlife Park are released at Knepp, and in 2020, three of these free-flying birds nested, for the first time, in oak trees in the Southern Block, one of them, amazingly, pairing up with a wild, unringed bird from Europe. Between the two nests the two pairs of storks reared four chicks all of which successfully fledged. It was the project’s first milestone.

However, it was not until 2023 that the colony of 25 non-flying Polish storks in the pen at Knepp showed signs of wanting to breed. Four of them paired up and one pair, in particular, began building a gigantic nest of willow branches and oak twigs bulked out with mud and rotting wood, protected on the outside by branches of spiky hawthorn and blackthorn.

We were excited to see eggs in both nests and, eventually, in mid-summer, a chick hatched out in the more modest nest which was barely more than an indentation in the ground; and, from the other magnificent nest, hatched Snappy and his sibling.

 Flightless storks like Snappy’s parents are limited to what’s available within their enclosure and what we provide for them. 

Although Snappy’s flightless parents were unable to teach him to fly he had twenty-six wild fledglings growing up in the colony around him to imitate – but he was primarily driven by instinct. Camera traps showed him exercising his wings on the nest, building up flight muscles, then hopping off the nest on short forays in the pen. Finally, in mid-July, he made his maiden flights out of the enclosure, returning to the nest for the first few nights and staying close by during the day. By mid-August satellite tracking data showed him venturing further afield, beyond Knepp, exploring the south coast of England along the coast to Kent, and back. The genetic urge to migrate appeared to be kicking in.

 We’ve learnt, from tracking white storks at Knepp for several years, now, that our British-born storks tend to patrol along the south coast of England, building up determination to migrate and scoping for the shortest water crossing and favourable winds. Storks are fantastic fliers, right up there with eagles and vultures, with a wingspan of up to two metres. But they need to find thermal currents to gain altitude and tail winds to propel them across large stretches of water. They like to fly in groups for safety in numbers and to help read the winds. These twisting formations of soaring birds are known as a ‘kettle’ and are truly spectacular to behold.

A PERILOUS CHANNEL CROSSING FOR MIGRANTS

Thermal air currents over bodies of water are typically weaker than those found over land, so the optimal route for a soaring bird like a stork is the shortest one available. Here they can ascend to high altitude with minimal effort, reducing the energy sapping activity of beating those enormous wings. Most of the white storks we are able to track cross the English Channel at a similar spot to the busiest human crossing – between Dover and Calais. However, Snappy was tracked crossing much further west (and closer to his Sussex home), leaving land at the Manhood Peninsula close to Selsey Bill.

We were a little anxious that attempting this considerably wider Channel crossing could cause exhaustion and possibly Snappy would never make it. There are records of migrating birds falling into the water and drowning in large numbers over similar distances across the sea.