You are probably correct about the bald head. Our ibis are shallow water feeders.Interesting that yours have feathers on their heads, ours are bald. Our frogs and crustaceans must bury themselves deeper in the mud than yours, that's the only reason I can think of for needing a bald head.
And what we call a White Ibis is also known as the Sacred Ibis, from Egyptian mythology when ibis saved them from a plague of frogs. They're the same species.
We have a Wood Stork that looks similar with a bald head, but is not an ibis. It is much larger.
Another bald headed bird is the otherwise splendid roseate spoonbill.
Both are in the same family as ibises, but are not ibises.