CURWOOD: It's Living on Earth, I'm Steve Curwood.

CURWOOD: It's just past the autumnal equinox, and now the days are shorter than the nights and the infallible signs of approaching winter are all around us. Still, this season does offers the joys of fall - here in the north, the harvest, the turning leaves and the departing birds. Here's Mary McCann with our BirdNote®.

MCCANN: In September, Arctic Terns fly south over the ocean, from Alaska all the way to Antarctica.

MCCANN: Also in September, the last Rufous Hummingbirds depart their breeding range in the West, following “floral highways” of mountain wildflowers south to Mexico.

MCCANN: Ruby-crowned Kinglets are leaving the northern evergreen forests where they nest, on their way to milder climates.

MCCANN: Each of these birds is migrating, but on a very different course. All have the same adaptive goal – making the most of food and breeding opportunities that change with the seasons. Arctic Terns follow one of the longest annual migrations, traveling as much as 44,000 miles each year. Arctic tundra provides their ideal nesting site in summer, the Antarctic, the ideal feeding grounds in our winter.

MCCANN: Rufous Hummingbirds are medium-range migrants, traversing about 5,000 miles a year between temperate and tropical nectar sources.

MCCANN: Some Ruby-crowned Kinglets are altitudinal migrants, especially in the West. They may remain close to the same latitude all year, but spend the cold months in the relative warmth of the lowlands dining on insects and their eggs. In summer, you’ll need to ascend thousands of feet into the western mountain ranges to hear the kinglet’s exuberant song.

I’m Mary McCann

CURWOOD: To find some photos, migrate over to our website LOE.org.