Brodhead...the spring break capital of the world?

There are literally hundreds of these Dark-eyed Juncos under our bird feeders, devouring anything that the woodpeckers let fall.  Why all the sudden activity? Although they've been here since October, they seem much more active, perhaps getting ready for their April journey home to the woods of northern Canada where they will breed. Is it possible that they are the original "snowbirds"? (image courtesy of Wikipedia)