Great Blue Heron, Ardea herodias
Above, a juvenile; the crown is solid gray rather than black and white, there is no brown on the neck, and wing coverts are cinnamon-fringed.
Adult Great Blue with two nestlings -- who are playing at bill-dueling.
A pair courting, with the adult version of bill-dueling (compare nestlings, next image up). For a sequence of eleven images showing this episode of courting and mating, see here.
Toward the end of the courtship, this male successively fetched three large branches which he presented to the female, this being one; she accepted and placed the branches crosswise as if for a nest.
The pair of birds shown in the courting display in the two images further above, now concluding the courtship with copulation.