The long heavy bill is black above and pink-based below.

All subspecies have a heavy yellow bill which gives the species its name.

They have a colourful plumage and a relatively heavy bill.

It is 14-15 centimetres long and has a heavy black bill.

Its long, heavy bill is black with a grey base.

It has a heavier bill than its larger relative.

It has a heavy yellow bill and a pointed black tail.

It has a deeply forked tail and a heavy black bill.

It has a heavy bill and has a short tail.

This species is a large cuckoo with a heavy bill and short wings.