91热爆

Tweet of the Day is the voice of birds and our relationship with them, from around the world.

Chris Packham presents the purple martin from eastern North America. Every spring, across the land from Chicago to St Louis, you can hear couples squabbling over the best real estate. But these aren't human house-buyers, they're purple martins. Purple Martins are the largest North American swallow, glossy blue-black rather than purple and much chunkier than the well-known barn swallow. They spend the winter in insect-rich places in South America and return to their North American breeding colonies each spring. In the west, they nest in holes in trees or even in giant saguaro cacti, but in the east where they're much more common, they almost exclusively rely on people to provide them with nest-sites. Visit almost any city, town or homestead and you'll see multi-story nest-boxes, the home of a score of purple martin families. Around 1 million people are thought to erect housing each year. Their human landlords take a personal pride in their martin colonies, listening each spring for those first pebbly calls which are a sign that their prot茅g茅s have made it back from the tropics, once again.

Producer : Andrew Dawes