The movements of winter finches, like the movements of most birds, are related to finding food. In years when there is a heavy crop of seeds, nuts, and berries in the north, relatively few of the little birds travel very far to the south. It is not the cold of winter that they flee. It is lack of food. As long as they have a sufficient supply of food they can survive the cold.
When the food crops fail or are less than normal, the lower 48 states can expect to see irruptions of birds such as Common and Hoary Redpolls, Evening Grosbeaks, Purple Finches, and Pine Siskins, as well as some of their fellow travelers like Red-breasted Nuthatches and Bohemian Waxwings. Those are very good years for birders throughout the country.
Now, of all these winter finches and irruptive passerines, the only ones that occasionally make it as far south as my backyard in winter are Purple Finches, Pine Siskins and Red-breasted Nuthatches. The last couple of winters in particular have been good ones for these visitors.
A Pine Siskin that lingered into spring in my yard this year.
I look forward to those Pine Siskin winters. They are fun birds to have in the yard. But the forecast indicates that I probably won't be seeing them this winter. It seems that there has been a bumper crop of food sources in the north and that will probably keep the birds up there.
Oh, well, thank goodness for American Goldfinches. That's one "winter finch" that we can depend on to visit and how they do brighten our dullest season.
An American Goldfinch in April of this year is beginning to change into its breeding colors.