This is Birdnode. You might think that Key West is at the very tip of Florida, but not quite.

Another 70 miles out in the Gulf of Mexico lies a cluster of tiny islands known as the Dry Tortugos.

Low, sparsely vegetated, and devoid of fresh water, the seven islands add up to less than a quarter-square mile of land.

For birds, these specks of land are vital. Millions of migratory songbirds fly north across the Gulf and Caribbean each spring, headed for North America.

If they run into the heavy wind and rain of a northern blowing down from the continent, the Dry Tortugos provide a safe haven.

Thousands of storm-tossed birds, warblers, thrushes, kukus and others, will seek shelter on the islands.

And migrants aren't the only birds to touch down here.

The islands also host more than 85,000 nesting sea birds. Many of them, city turns.

So for many birds, this miniature archipelago is a life giver as well as a life saver. For birdnode, I'm Michael Stein.

Support for birdnode is provided by Sarah Murner and Craig McKibben from Seattle, Washington, and generous listeners around the world.