Noddies are members of the tern

Tern

Terns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...

 family Sternidae in the genera Anous, Procelsterna, and Gygis. They are a tropical group, characterised by the notch-wedge shaped (not forked) tail; coastal and pelagic oceanic. Studies of mtDNA sequences

DNA sequence

The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

 (Bridge, 2005) have shown that the noddies are at least 2 groups that split off early from the ancestral terns at different points of time; the relationships of Procelsterna were not researched for lack of samples. It seems to represent either a third lineage linking the noddies and the marsh tern

Marsh tern

The name marsh tern refers to terns of the genus Chlidonias, which are typically found in freshwater marshes, rather than coastal locations.There are four species:* Black Tern, Chlidonias niger...

s, or is closely related to Gygis.

Genus Anous

• Brown Noddy
  Brown Noddy
  The Brown Noddy or Common Noddy is a seabird from the tern family. The largest of the noddies, it can be told from the closely related Black Noddy by its larger size and plumage, which is dark brown rather than black...
  
   or Common Noddy, Anous stolidus
• Black Noddy
  Black Noddy
  The Black Noddy or White-capped Noddy is a seabird from the tern family. It resembles the closely related Brown or Common Noddy , but is smaller with darker plumage, a whiter cap, a longer, straighter beak and shorter tail...
  
  , Anous minutus
• Lesser Noddy
  Lesser Noddy
  The Lesser Noddy , also known as the Sooty Noddy, is a species of tern in the Sternidae family.It is found in Comoros, Kenya, Liberia, Mauritius, Seychelles, South Africa, and United Arab Emirates.- References :...
  
  , Anous tenuirostris

Genus Procelsterna

• Blue Noddy
  Blue Noddy
  The Blue Noddy is a species of tern in the Sternidae family. It is also known as the Blue-grey Noddy.It is found in American Samoa, the Cook Islands, Fiji, French Polynesia, Kiribati, Marshall Islands, New Caledonia, Samoa, Tonga , Tuvalu and Hawaii. It has occurred as a vagrant in Australia and...
  
  , Procelsterna cerulea
• Grey Noddy
  Grey Noddy
  The Grey Noddy or Grey Ternlet is a seabird belonging to the tern family Sternidae. It was once regarded as a pale morph of the Blue Noddy but is now often considered to be a separate species....
  
  , Procelsterna albivitta

Genus Gygis

• White Tern
  White Tern
  The White Tern is a small seabird found across the tropical oceans of the world. It is sometimes known as the Fairy Tern although this name is potentially confusing as it is the common name of the Fairy Tern Sternula nereis...
  
  , Gygis alba
• Little White Tern
  Little White Tern
  The Little White Tern or Little Fairy Tern is a subspecies of tern . It is sometimes considered a distinct species most closely related to the larger White Tern. It is found in French Polynesia and Kiribati.-References:* BirdLife International 2004. . Downloaded on 24 July 2007....
  
  , Gygis microrhyncha

Noddies are reportedly a dietary staple on the island of Nauru

Nauru

Nauru , officially the Republic of Nauru and formerly known as Pleasant Island, is an island country in Micronesia in the South Pacific. Its nearest neighbour is Banaba Island in Kiribati, to the east. Nauru is the world's smallest republic, covering just...

.