Knokke (Brussels Morning Newspaper) – A young stork from Zwin Nature Park in Knokke skipped its usual migration to Africa and instead spent winter at a landfill site in northern France.
The Zwin attaches new storks with transmitters each year. One young stork was only 100 kilometers away from home, which is the transmitter study’s most startling discovery.
As migrating birds, storks head south for the winter at the end of August. They occasionally even travel 4,000 kilometers to reach Mali. For years, the Zwin Nature Park has been studying this migration, including the storks’ flight altitude, destination, and duration of stay. The Zwin has been giving transmitters to young, new storks every year for the past seven years.
“We made a remarkable discovery this year,”
says director Ina De Wasch.
“A young stork born last year in the Zwin National Park ended up 100 kilometers from the Zwin last winter, at a landfill in Blaringem, northern France. He foraged there and stayed there all winter, among older storks.”
“Storks have an innate migratory instinct,”
explains researcher Wouter Faveyts.
“But they’re also social animals. They adapt easily. They discover that food is readily available at waste processing sites across Europe. That’s where they stay.”
“So as storks get older, they stay closer to home and no longer migrate all the way to Africa,”
De Wasch continues.
“The older they get, the less far they migrate, was an earlier conclusion from our transmitter project. But a young stork always migrates far away. So for a young stork, it’s truly exceptional that it stayed so close.”
So far, only one young stork hasn’t migrated far.
“We’re very curious to see if he’ll become a trendsetter,”
wonders Favetts.
“For now, he’s the exception to the rule, deciding at such a young age that Northern France is good enough. This spring, we fitted eight young storks with transmitters. And of course, we’re very curious to see what these eight will do. Most of them will probably migrate very far.”
“The fact that they’re overwintering on a landfill close to home isn’t great news for the young storks’ health,”
Wouter Faveyts continues.
“They’re eating junk food on the landfill, food that’s not very healthy. And what’s more, they can ingest plastic or get entangled in it, so there are certainly significant risks involved. But at the same time, we see that the stork population in Belgium, and indeed throughout Western Europe, is doing well! Better than it has been for many decades.”
The transmitter project to track the stork migration will undoubtedly continue at the Zwin Nature Park in Knokke, Belgium. 39 Zwin storks have already had transmitters installed since the experiment started in 2018, and 17 of them are still alive. Each year, transmitters are fitted to new juvenile storks.
About 20 storks can be found in the Zwin right now, including both juvenile and adult birds that will go in the upcoming weeks. According to the transmitter research, on a pleasant day between August 10 and August 20, juvenile birds depart toward the south.
How other bird species in Belgium exhibited similar changes in migratory patterns due to abundant local food sources?
Urban-adapted species such as blackbirds (Turdus merula), starlings, and thrushes are increasingly overwintering in western and central Europe, including Belgium, rather than migrating to southern Europe or Africa. Urban environments offer consistent, human-provided food resources (e.g., waste sites, bird feeders), making long migrations less necessary.
Colourful migratory birds like the European roller, bee-eater, griffon vulture, and black-winged stilt—species that traditionally nested in warmer southern Europe or Africa—are now being observed in Flanders, sometimes even breeding there.
Their presence is linked both to climate-driven milder winters and shifting local food availability.
