Noddies are tropical or subtropical members of the tern family. Three species are the brown, black and grey noddies. The other is the white tern. All lack the black cap of the other terns.
Only black noddies and grey ternlets live in large numbers in the New Zealand region. Their numbers are sure to increase following the eradication of rats and cats on Raoul Island in 2002.
Why are they called noddies?
Sailors may have given noddies their name because of the way the birds nod during courtship. But ‘noddy’ also means a simpleton, and the birds were thought of as stupid. Charles Darwin seemed to think so when he encountered them during his 1831–36 voyage on the Beagle: ‘The noddies, as their name expresses, are silly little creatures.’ 1
The brown or common noddy (Anous stolidus) was discovered in the New Zealand region in 1989, with 25 pairs breeding on Curtis Island in the Kermadec group. Norfolk and Lord Howe islands are the other nearest breeding sites. They can also be found in the tropical and subtropical Indian, Atlantic and Pacific oceans.
Brown with a pale grey cap, they are 39 centimetres long and 200 grams in weight.
The black noddy (Anous tenuirostris), also known as the white-capped or lesser noddy, breeds in the Kermadec Islands, where there are about 1,100 pairs. Smaller than brown noddies, they are 34 centimetres long and weigh just 100 grams. Their plumage is dark brown, with black in front of the eye, and a silver-grey cap that extends down to a long, slender bill. They feed on fish and plankton.
The grey noddy or grey ternlet (Procelsterna cerulea) is 28 centimetres long and weighs 75 grams. They are blue-grey, with a paler body that becomes progressively darker along the wings. They have a small black patch in front of the eye, and a lightly curved, slender black bill.
Grey ternlets are found in the tropical and subtropical Pacific. The New Zealand population of around 17,000 pairs breed on the Kermadecs. Some years they also breed on Three Kings and visit other islands east of the northern North Island. They lay one egg in shade on bare rock or under plants.
The white tern or white noddy (Gygis alba) breeds on Raoul Island in the Kermadec group, and on nearby Lord Howe and Norfolk islands. They are pure white, with a black eye ring, a fine-tipped, straight bill and a short, slightly forked tail. Small and slender, they grow to 31 centimetres and weigh 110 grams.
They do not build nests, but lay a single egg in the depression of a branch, in pōhutukawa or Norfolk pine trees. Hatchlings cling to the branch with their long claws. When disturbed by predators, the adults hover, flutter and make twanging and buzzing sounds.