Migratory wildlife is the stuff of legend – astonishing journeys made in extreme conditions under huge pressures. Some of those listed below verge on the incredible, says James Fair.
Indeed, the 18th century naturalist Gilbert White never quite abandoned his belief that swallows and other hirundines (such as house martins) hibernated in the mud at the bottom of ponds despite the evidence of birds in the same family being seen thousands of miles away in Gibraltar during the autumn. Even today, it can be hard to believe that some creatures make these crazy trips – but they do.
10 craziest migrations
Monarch butterflies
Though not the only known insect migration, this is definitely the most famous, partly because of the sheer numbers – tens of millions of animals – but also because of the multi-life-stage aspect to it. Starting with adults that overwinter in the mountains of Central Mexico, as spring brings warmth to the frigid oyamel fir forests, they wake up, mate and depart for the north.
Eggs are laid on milkweed, and a new generation returns to their parents’ haunts in the northern US and Canada. Remarkably, up to three or four generations hatch, metamorphose and die before the great great great grandchildren begin the nearly 5,000km odyssey south, and the whole cycle starts again.
Corncrakes
A bird the size of a blackbird and resembling a dumpy pigeon shouldn’t be able to fly thousands of miles across Europe and much of Africa to escape the winter.
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But that’s what a corncrake does, returning in the spring to large parts of northern Europe, including a number of Scottish islands in the Inner and Outer Hebrides where they mostly live unseen, the only signs of their presence being their unique rasping call that resembles someone playing a washboard and which fills the air at dusk and into the short summer nights.
European corncrakes mostly head to south-eastern Africa, but our British birds, we now know, plump for the mysterious tropical forests of the Congo Basin.
Wildebeest
In some ways, the famous wildebeest migration of the Serengeti is misleadingly-named because it’s really just a more-or-less endless trek of up to 1,500km every year.
- Gob-smacking BBC footage shows young wildebeest faced with a lethal almost suicidal cliff-face drop – does he jump?
- Jaw-dropping videos of a million wildebeest migrating across Africa – and the infamous Mara River crossing where hungry, deadly crocodiles await
They circle round northern Tanzania and southern Kenya in search of fresh grass that emerges with the increasingly unpredictable rains. Images of thousands of wide-eyed wildebeest, along with some zebras and gazelles, massing on the banks of the Mara and Grumeti rivers, waiting to take their turn to run the gauntlet of hungry crocodiles, epitomise this iconic migration.
Arctic terns
It’s said that Arctic terns see more daylight than any other species on Planet Earth – that’s because their migration takes them from the Arctic summer to the Antarctic summer and back again every year, covering a staggering 80,000km or so in the process, enjoying long (and in some cases, endless) days at both poles.
- Arctic terns travel faster in large flocks
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- The Arctic animals that not only survive, but also thrive, in this inhospitable freezing landscape
During its lifetime, a single Arctic tern can fly the equivalent of going to the moon and back three times. And all this on a wing span of just 70cm and with a body weight of about 100 grams.
Savannah elephants
The world’s largest land mammal is not known for its migrations, but there’s one particular population that undertakes a 700km journey from Botswana to Angola, crossing human-dominated landscapes and deserts. Or they did. Land mines in the Angolan part of the route has made it inaccessible for savannah elephants. It’s hoped that by one day clearing the mines, the elephants will be able to resume their traditional migration in full.
7. European storm petrels
Another seabird that must withstand almost unbelievably harsh conditions is the European sea petrel. The species nests on mainly offshore islands of northern Europe – islands such as Mousa in Shetland and Bardsey off the coast of north Wales – but come the autumn, it departs and heads south across the storm-battered Bay of Biscay and down to the southern tip of Africa. And this from a bird no bigger than a sparrow, weighing just 28 grammes and regarded as being the smallest seabird in the world.
Orange-bellied parrots
We think of parrots as birds of tropical rainforests, entirely non-migratory and slightly cumbersome fliers. But there’s always the occasional exceptions that prove the rule, and one of these is the orange-bellied parrot which migrates from southern Tasmania across 240km of the Bass Strait to southern Australia for the antipodean winter.
As well as being one of only three migratory parrots, the OBP (as it is sometimes called) is also one of the rarest, with the latest figures suggesting only 172 individuals migrated from their main breeding site of Melaleuca in in the Tasmanian south-west.
European eels
The starting point of the European eel’s migration is the Sargasso sea, an area of the north-west Atlantic known for its brown sargassum seaweed, where adults spawn and then die.
Tiny eel larvae drift slowly east on ocean currents for one to three years, before the next stage of their life. Off the coasts of the UK and mainland Europe, they transform into transparent eels and enter estuaries and freshwater rivers, and here they grow and mature over a period of up to 20 years. When the time comes, they respond to their instincts and begin the 5,000-6,000km journey back to the Sargasso Sea, where the whole mysterious, remarkable lifecycle begins anew.
Gray whales
Mammals are not as well-known as birds for undertaking migrations, but many do carry out remarkable long-distance journeys.
Gray whales are thought to perform the longest of all mammals, more than 20,000km annually from the northern Bering and Chukchi Seas of the Arctic (where they feed) to the warm-water lagoons of Baja California where they give birth to their calves and mate.
A much smaller population of gray whales – about 200 to 300 individuals – migrates along the coast of Asia to the seas off Japan, China and occasionally as far south as Vietnam.
