The white morph is similar in general appearance to the Little Egret, but has a thicker bill, duller legs, and a less elegant appearance.
The white morph has bluish-grey upperparts (similar to the nominate group), but its underparts are all white except for its rufous thighs.
Authorities were still not in agreement and some argued that the black color morph was a different species from the mostly white morph.
On Oahu, a white morph of the monarch has emerged.
Because of its colour, the white morph has a higher survival rate than the orange one.
In the white morph the plumage is mostly white (the head often tinged yellowish) and the flight feathers are black.
Unlike the Asian Paradise Flycatcher there is no white morph.
The white morph is the only bird of prey in the world to be entirely white.
The adult white morph has completely white body plumage.
The dark and white morph is thought to be controlled by a single allele with the dark character being incompletely dominant over the gene for white.