On World Migratory Bird Day, we celebrate one of nature’s greatest wonders – bird migration. Twice a year, we marvel at this extraordinary spectacle as migratory birds undertake epic journeys around the globe, connecting and inspiring people along the way.
Why do birds migrate? Not all birds stay in the same place their whole lives. Some migrate to take advantage of seasonal resources, especially food, so that they can breed successfully or simply survive. Some migrations are short, but many birds make truly epic journeys, crossing continents, deserts and oceans.
From RSPB: Globally, around 2,000 species of bird are regular migrants. That’s about 20% of the world’s total. But some parts of the world have a higher proportion of migrants than others.
In northern regions such as Canada and Scandinavia, and temperate regions, such as the UK, about half the species migrate – especially insect-eaters. These species visit in spring to take advantage of the high numbers of insects, but wouldn’t have enough food if they stayed here through winter.
In tropical regions, such as the Amazon rainforest, a lower proportion of species migrate long distances, since the climate and food supply there are more abundant and consistent all year round.
A bird’s urge to migrate is hormonal, with the change in natural sunlight triggering hormones that make them become restless, gather in flocks
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