U is for Unbelievable Migration

To the moon and back

The Arctic Tern is now known to complete an astonishing annual round trip of 96,500km (60,000 miles) between Northumberland and Antarctica. In its lifetime it could clock-up the equivalent of  4 trips between Earth and the Moon!


Every year birds, fish, whales, butterflies, moths, bats and even snails make extraordinary journeys as they migrate between breeding and over-wintering locations.

By tagging animals with miniature transmitters, and tracking them via satellites and radar, we can follow their routes and discover just how far they travel.


How do they do it?

The Quantum Robin

As well as using the sun, stars and a mind map of landmarks, research is revealing that birds, such as the European robin, are able to see and follow Earth's magnetic field.

While we need Sat Nav to find our way, the humble robin has a built-in compass in its eyes and brain.

How does it work?

Through light sensitive molecules in its eyes, called cryptochrome, and a complicated process of quantum mechanics.

The robin can somehow see the differing strengths of the magnetic field and follow the direction it needs to travel.

Think of a Robin wearing virtual reality goggles with a Sat Nav image superimposed in front of its eyes to guide it!

The European Eel


The European eel's migration to the Sargasso Sea to spawn is one of nature's great unsolved mysteries.

For many years, biologists have puzzled over exactly where they go and what they do after leaving our rivers.

Now scientists using satellite tags have tracked 22 eels, revealing what they do in the first 1,300km of an epic 5,000km migration.

Using this method, biologists hope the whole journey to the Sargasso Sea will soon be revealed.

The Painted Lady

One of the longest standing mysteries of migration has finally been solved (2016) after scientists discovered where the UK’s Painted Lady butterfly population goes each autumn. Radar records revealed that Painted Ladies fly at an average altitude of over 500 metres and can clock up speeds of 30 mph. A phenomenal 9,000 mile round trip from tropical Africa to the Arctic Circle – almost double the length of the famous migrations undertaken by Monarch butterflies in North America.
The whole journey is not undertaken by individual butterflies but is a series of steps by up to six successive generations so Painted Ladies returning to Africa in the autumn are several generations removed from their ancestors who left Africa earlier in the year.

The Swallow


British swallows spend their winter in South Africa - they travel through western France, across the Pyrenees, down eastern Spain into Morocco and across the Sahara. 

Migrating swallows cover 200 miles a day, mainly during daylight, at speeds of 17-22 miles per hour over a total distance of 12,000 kilometres . The maximum flight speed is 35 mph. In their wintering areas swallows feed in small flocks, and they do not breed, but return to the UK in April and May to nest and raise young.