Today is the first day of spring, and hummingbird migration is underway.
With your help we'll track one species of hummingbird, the ruby-throated, as it hums its way across eastern North America this spring. On the left-hand side of this page you'll see a blue owl button. There are no hummers in Europe, Asia or Africa or Australia. They're unique to the Americas. There are an estimated 338 species in total, and most live in the tropics.