The members of this genus primarily eat zooplankton by filtering water through their upper beak.

Beak: Long thin and straight, the upper beak being slightly curved at the tip.

The male is about 5% longer than the female, and the male's upper beak is 12-14% longer than the female's.

Most species have a hooked upper beak, tails with fourteen feathers, and in many of them the male has tarsal spurs.

The curved upper beak has the nostril opening exposed.

The upper beak is curved and comes to a sharp point.

The greater portion of the muzzle and upper beak are missing.

Rhynchokinesis is an ability possessed by some birds to flex their upper beak or rhinotheca.

It is mostly olive-green and has a large narrow curved grey-brown upper beak.

The trimmed lower beak is somewhat longer than the upper beak.