The underparts are entirely white, a feature unique for the genus; even E. grandidieri has dark gray underparts.

Race saturatior is found in the Andaman Islands and is larger with darker brown underparts.

The eastern subspecies P. r. mentalis has darker underparts and a grey-brown eye.

They can be distinguished from immature Reed Cormorants by their darker underparts and shorter tail.

The marsh shrew is dark brown in colour with dark underparts and a long tail.

Though it has some similarities to the Northern Mockingbird, particularly as to the tail, its dark underparts, shape, size, and behavior are not similar.

It has dark hairs on the neck and dark underparts, followed by a light-colored rump patch.

These doves are larger than usual with males having darker brown underparts.

It has dark underparts and an indistinct pale grey rump.

The male is metallic green above with glossy dark blue underparts and a brownish wing panel.