For most of my life, I didn’t pay attention to birds.

Now, when someone asks me why birds are so important to me, all I can do is sigh and shake my head, as if I’ve been asked to explain why I love my brothers. And yet the question is a fair one:

Why do birds matter?

My answer might start with the scale of the bird kingdom. If you could see every bird in the world, you’d see the whole world. Things with feathers can be found in every corner of every ocean. They’re found on land habitats so bleak that no other animals live there.

Gray gulls raise their chicks in Chile’s Atacama Desert, one of the driest places on Earth. Emperor penguins lay their eggs in Antarctica in winter. You can find sparrows in New York City traffic lights; swifts in sea caves; and vultures on Himalayan cliffs. The only forms of life more widely distributed than birds are microscopic.