Rather than search for worms in the frozen soil, large winter flocks of robins will visit fruit trees for food.
Cedar Waxwings will visit yards in search of fruit, often staying for hours before moving on.
Juncos will hunt for fallen seed, often before dawn.
The smaller the bird, the earlier its hunt for food in the winter darkness.
In preparation of the earliest nesting period of any bird (late-January through February), Great Horned Owls can be heard hooting at night in courtship.
Now through late March is a difficult time for birds; providing food and an open source of water is important.
Winter is a great time to look for birds' nests. Admire the craftsmanship, but leave the nest in place.