The Swallow's Migration: An Epic Journey
Swallows and Cows
British or South African?
Here in Britain, we have a tendency to think of swallows as being on of our own, our personal property. When they first individuals start filtering back into the UK around the end of April, we always think of them as coming back to their rightful home. We observe them swooping over fields of long grass and dodging the black and white hulks of Friesan cows and consider it to be quintessentially English. We rejoice at our first sight of them, as we know that the short, dark and gloomy days are coming to an end, summer and all the delights that come with it is just round the corner.
But there is another country where the swallows return is also rejoiced and heralded as the start of the summer season; it's in a different hemisphere, South Africa, there it's November and December when the swallows are 'welcomed home'. it seems that this well travelled bird is welcomed almost anywhere it goes in the world, and is thus universally popular across both hemispheres.
A traditional end of Summer sight in Britain and Europe
Start of the Journey
In recent years, a great deal of research has been conducted to uncover the secrets of the more mysterious aspects of a swallow's life, the annual journey that it makes from its northern breeding grounds to its southern wintering grounds. Thanks to the work of bird ringers, who fit an individual with a ring in the hope it will be recovered in some far flung place, we can at least piece together more or less the entire route from Britain to South Africa.
The swallows remain around their breeding sites until the end of August, this is the month that marks the start of the journey south. Initially they will make a few short hops of a few miles, to places where they can roost safetly at night, this is the time when we see flocks of swallows perched on telephone wires twittering to each other and shifting about restlessly. Progress is slow, usually taking them about a month or even two to reach the English Channel, which isn't too much of a hinderance because for them it's a short hop of around 20 miles of water. Next, they proceed down a strip of coastal France about 60 miles wide. By now, they've been on the go for several weeks and they are starting to make faster and faster progress, buoyed by good fat reserves collected en route and a slow and steady start.
When they reach the Pyrenees Mountains that divide France and Spain, they make a surprising decision, instead of just flying straight over the mountains they head eastwards along the northern rim until they reach the Mediterranean coast. At this point some swallows may fly down along the eastern coast of Spain, passing over the iconic city of Barcelona, while others will strike out over the sea towards Africa, with a brief pit stop in the Balearic Islands.
A lone Swallow flying over the Desert
- Nigerians' taste for a bird proves hard to swallow - World - News - The Independent
A report from the Independent highlighting the slaughter of Swallows at Ebok Boje.
Whichever route the swallows decide to take, they must cross the Mediterranean to reach North Africa and the ever looming Sahara Desert. The birds however, have been expecting a major barrier and are instinctively prepared for it. It seems, from the research and data collected, that the desert doesn't pose as much of a problem for them, as you might think. They complete the Saharan section with little fuss and in one long haul, although a few elect to travel along the fringe of the west coast of North Africa, perhaps flying over the Pyramids at Giza.
The next stage of the journey sees our swallows venture into West Africa, to be more precise Nigeria. Here, they encounter their toughest hazard thus far, a hazard of gigantic proportions. At a place called Ebok Boje, one of their stopping off and roosting spots, over a hundred thousand swallows are killed for human consumption, in what is an annual tradition. They are captured at night, while roosting in tall elephant grass. It's a place of great peril for swallows travelling from all over Europe, and there may be other sites where similar slaughters are occurring that haven't been documented.
Once the hazards of West Africa are behind them, the trail goes temporarily cold. From Nigeria, they may move east and south towards the giant forested belt of Central Africa, to places so remote that, no European has ever set foot there. I can imagine them passing over the heads of okapis, forest elephants and chimpanzees. As they go, they sweep up tropical insects that humanity has never seen, let alone described. Or perhaps, they jump from open space to open space, brushing past giraffes, savannah elephants and lions. Whichever way they go, by now they are coasting along nicely, managing many miles a day, as their final destination draws ever nearer.
Swallows roosting in reedbeds
Swallow Migration Map
In just a few short weeks, the vast tropical forests are behind them, and they enter more open country, typical of Southern Africa. The swallows continue to press on, but they are preparing to stop, instinctively they know they are close to the end of the journey. No one quite knows how they do it, but somehow the swallows know to stop in just the right place, few if any fly out beyond the Cape and into the vastness of the Southern Ocean.
So, finally after four months, just as Christmas is rolling round for us in the north, they finally reach their destination, which is usually Botswana, Namibia or South Africa. The swallows have swapped hemispheres and returned to their favourite season, summer. Once in their wintering grounds, they take opportunity to moult, and cross paths with other swallows that have travelled from all over Europe.
The swallow's epic journey south lasted four months from September to December, it was mostly quite a leisurely affair, but after just two months of filling their bellies with African insects, they must begin the equally epic journey back to Europe. The journey north is a much different proposition, instead of a leisurely pace, the pace will be frantic, as they race to get back to their breeding grounds as quick as possible in order to re-establish their breeding territory before another swallow beats them to it. As a measure of comparison, whilst the journey from Britain to South Africa takes four months, a fit and experienced swallow can complete the opposite journey in just five weeks, travelling an incredible 190 miles a day. When you look at this way, maybe the swallow belongs in Britain after all.
© 2012 James Kenny