Blue-billed white tern
The blue-billed white tern is a small seabird found in Pacific and Indian oceans. This species was previously considered as conspecific with the white tern and the little white tern, but is now recognised as a separate species. It is known as manu-o-kū in Hawaiian. In the Cook Islands, it is known as the kakaia.
Taxonomy
The blue-billed white tern was first formally described by the German ornithologist Johann Friedrich Gmelin in 1789. The species epithet is from Latin candidus.There are two recognized subspecies of the blue-billed white tern - Gygis candida candida - Indian Ocean - and tropical Pacific Ocean Gygis candida leucopes - Henderson Island, Pitcairn Island
Description
A medium-sized all-white tern.The eyes are narrow and are dark in colour. The bill is black in color with blue in the base, hence its name. The shape of the bill is thick and "daggerlike" with a sharp-pointed tip. Legs are slaty-blue in color, with yellow or white webs.The immature is similar to the adult, except the body and wings are fringed with brown and the base of bill is black in colour.