A bird with bravado

By Anna Wild, Te Arai Beach Preservation Society

In 1888, Walter Buller described the New Zealand fairy tern as “tolerably common”. Today, with around 40 birds remaining, it is the rarest bird in the country. While many people are aware of these terns’ scarcity, the energy they expend in their fight for survival is less well-known.

Weighing in at 70 grams, the NZ fairy tern is the smallest of all NZ terns. For a creature weighing less than half an apple, it possesses sizable bravado. A fierce defender of its nest and chicks, the NZ fairy tern can be found fighting off far larger birds. An approaching human is often met with dive-bombing and defecation from the birds. This time and energy spent on defence reduces the amount left for fishing and raising their young so keeping levels of disturbance low is critical. Sightseeing is not encouraged.

Prospecting for nesting sites usually begins in October and the nesting season runs until February. There are only four breeding sites – Waipu, Papakanui Spit, Mangawhai and Pakiri. The Mangawhai Wildlife refuge site is the most-favoured with over half of the terns breeding there. NZ fairy terns are very particular about their nesting sites, requiring a large area of exposed sand with shelly patches. The colours of broken shell, such as the pink of scallop shells, aid in camouflaging the eggs and the chicks.

The male and female take turns incubating eggs and catching fish. Their change-overs are frequent and the returning bird will normally bring a fish for the incubating bird as refreshment before it takes off to fish. After 21 to 23 days, the chicks begin to hatch. Nesting sites are roped off at least 50 metres from the nest though the chicks are intrepid and can outgrow these confines. For three weeks, they are frequently fed fish by their parents until they have learned to fly and then the fishing tutorials begin.

This is where spots such as the Te Arai stream and lakes are important for the fairy tern, as they provide areas where the adult birds can teach their young to fish. Wildlife Service footage from the 1960s shows the fairy tern once nested from Pakiri right along the coast to the Mangawhai Wildlife Refuge. In more recent years, pairs have been sighted prospecting at Te Arai stream and if the area is left undisturbed, the birds may once again nest there.

How you can help

If in the rare instance you do see a fairy tern, stay low to the ground and watch where you step. If you are keen to watch the birds in a mindful way, consider volunteering with About Tern. Info: Jane Vaughan, 431 5828 or www.tearai.org.nz

Published 18 January 2012