Spring on the Wing?

It's one of the colder mornings of the year, but the birds don't seem to notice. They're rustling about in the azalea bushes, flitting from branch to branch of the denuded oaks.

They harken to some older signal, some lengthening of the day, some freshening of the wind.

They seem to think it's spring, or at least the beginning of it.

Who am I to disagree?