Pied Heron (Egretta picata)

immature dark-backed with white head, neck, underparts and yellow bill and legs -- I did not realize what it was until later; adult not much taller than the Wandering Whistling-Ducks among which it stood; slender plumes from whitish breast splayed like a long fringe across belly; dark areas seemed almost green-black; dark "tail" from cap; bright yellow bill and legs