Most fish-eating birds that breed where most bodies of water freeze over in the winter migrate further south in the fall, including Great Blue Herons. Movement of this large wading bird takes place largely from September to mid-October. According to Christmas Bird Count data, the Great Blue Heron has the widest wintering distribution of any heron species in North America.
While the number of Great Blue Herons in the Northeast is greatly diminished in November and December, it’s not uncommon to spot lingering birds at this time of year. Come January, when most bodies of fresh water are inaccessible to herons, sightings become rare until they begin returning in March.
Where open water remains in the Northeast, those Great Blue Herons braving the cold continue to consume fish, insects, amphibians and crustaceans. Small mammals, especially voles, and birds remain a warm-month delicacy, when mammal hair is cast in pellets and bones are digested.
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