Look to the skies at this time of year and the chances are you’ll see flocks of birds in the air, all flying together in the same direction. These birds aren’t just flying for the fun of it – they’re off to spend the winter months in a warmer place, and this type of behaviour is called migration.
Many different species of bird migrate every year to avoid the cold, dark winter in the UK. They often travel thousands of miles to other, warmer parts of the world such as Africa and the Mediterranean.
About 40% of all the species of birds in the world migrate – that’s around 4,000 species! In the UK, the percentage is much higher, with about 50% of birds in the UK migrating every autumn.
So why do birds migrate? It’s usually in search of food, which is particularly true for the birds whose main food source in insects.
Many birds will spend summer months in the north where they breed and feed. When the winter months come around, the drop in temperature means far fewer insects for them to feed on, so they fly south to warmer parts of the world where the insects still thrive.
In the UK, we get three types of migrating birds – summer visitors, winter visitors and passage migrants.
Summer visitors are the birds like swallows, cuckoos and ospreys that live here in the summer, then move to warmer countries in the winter.
Winter visitors are birds that usually live further north than the UK, so they migrate here for winter, returning to the north when the spring comes.
And finally we also get passage migrants. These birds use the UK as a stopping-off point – a bit like a motorway services – to rest and eat before continuing on their huge journey. A good example are smaller dunlins, who travel a whopping 6 to 7 THOUSAND miles on their journey from Greenland and Iceland to West Africa. That’s a long way to fly for your winter holidays!
What kinds of birds might you spot if you look up to the sky this autumn? These are some of the most common and recognisable.
Geese – These birds are easy to spot in the sky because they tend to form a v-shape when the fly all together. Interestingly, some of the geese you’ll spot at this time of year are summer visitors, so are on their journey south, and others like the Brent Goose are winter visitors, just arriving to spend their winter here.
If you want to know why they fly in a v-formation, there’s an interesting (but pretty technical) explanation on the National Geographic website.
Swallows – Swallows are beautiful, quick little birds and they are easy to spot with their long forked tails and rusty-red chin patch. Swallows from the UK have a long migration ahead of them: they fly across the Sahara desert and the Congo rainforest all the way down to South Africa and Namibia.
If you want to try and spot some migrating birds, all you have to do it look upwards during the day! Certain types of habitat are better than others though, so places like estuaries, wetlands and lakes which tend to attract a lot of birds are a good place to spot the Summer migrants fly off. If you are lucky, you might even spot some winter migrants arrive!