The dead leaves adrift on the water’s surface are a poignant reminder of the season’s end, and a promise of rebirth in the spring. In a similar manner, the worn plumage of the Great Blue Heron hints at its renewal by molt.
Online, I was able to find only brief references to this bird’s molting habits. Several writers pointed out that the juvenile molts four times in its first two years of life, as it sheds its youthful plumage in favor of adult feathers. Another mentioned that the adult molts before the breeding season, which in these parts occurs from March through May.