In the beginning

Swallow perched on overhead cable
Swallows make the long journey south to Africa every year

We have to look back to prehistoric times to understand how migration started. About one million years ago, during the last ice age, Europe was much cooler than today. Ice sheets covered much of the north and east - making life too tough for most animals. The majority of bird species lived in southern Europe and Africa, where it was warmer and there was more food.

As the ice age came to an end, the ice sheets began to shrink northwards towards the Arctic. They left behind them a brand new landscape, where the short, wet summer with its long hours of daylight was perfect for insects. 

If you’ve ever battled midges in Scotland, you’ll know just what this must have been like! But billions of bugs make a delicious feast for birds, which started to explore this ‘empty’ new habitat in the north. 

As well as plenty of food, they found good places to breed, few predators and not much competition from other birds. But in winter the weather got cold again and the food ran out, so some birds headed back south. The ones that left fared better than the ones that stayed put. Soon some started to make the journey regularly. 

As the ice sheets shrank further, the northern lands started to fill up with birds. Some species had to travel even further north to find a place of their own. 

But however far they went, they still had to return every year to their old wintering quarters in the south. Over time, these journeys developed into the long-distance migration routes that we know today.

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