CURWOOD: Once we pass the fall equinox, the days grow shorter swiftly. Here in the north, the leaves are turning color. And as BirdNote’s® Michael Stein explains, October brings another definitive sign of autumn.

STEIN: The syncopated honks of Canada Geese are among nature’s definitive heralds of autumn migration, as V-shaped flocks of geese fly south. Millions of Canada Geese migrate each year, although in recent decades, growing populations of non-migratory geese have remained in many parts of the country throughout the year.

STEIN: One reason for the change is that humans have introduced geese to these areas. Still, as October arrives, another voice tells us that some geese have not compromised their migratory ways a bit.

STEIN: You’re hearing Cackling Geese, which sound like a falsetto version of the familiar Canada Goose.

STEIN: Cackling Geese resemble a toy version of Canadas, with shorter necks, rounder heads, and stubbier bills. The smallest Cackling Geese measure just a shade bigger than a Mallard. The Cackler’s small voice suits perfectly its small size.

STEIN: It was once considered a diminutive form of Canada Goose, but recent genetic research has shown the Cackler to be a separate species. They breed in far northern Canada and western Alaska, and winter along both coasts and in the southern Great Plains.

STEIN: Look, and listen, for pint-sized Cackling Geese this fall at refuges, in farm fields, and at other spots where migratory geese gather.

STEIN: For BirdNote®, I’m Michael Stein.

CURWOOD: For pictures of Canada Geese and their smaller cousins, Cackling Geese, flap on over to our web-site loe.org.