The New Zealand fairy tern is the smallest tern that breeds in NZ.
The average lifespan of a NZ fairy tern is less than 10 years (Ferreira et al 2005), however, two individuals are known to have survived into their 19th year.
Their nests are scrapes in shell-covered sand, usually above the spring high tide mark, on only five North Auckland beaches.
Unlike all other tern species breeding in NZ territorial waters, NZFT do not nest in conspicuous colonies. NZFT nests are often kilometres apart.
Average incubation is 23 days.
Chicks fledge after three weeks.
Both sexes incubate their eggs.
Male birds provision themselves, their partner and their chicks.
Females source food for their chicks and themselves.
NZFT eggs are predominantly ovate and buff/sand coloured with tiny dark splotches, weighing 12-13 grams and measuring 25mm X 35mm.
Some breeding females, who have repeatedly lost early clutches, have laid seven eggs in one season, which is more than their own body weight.
Fairy Tern pairs have their own foraging area, which is vigorously defended from others.
On October 9th 2018 a fairy tern nest was discovered at Mangawhai by the DoC Ranger (Keven Drew), the earliest nest recorded and by the 15th of October there were four nests recorded. The previous earliest nest; also at Mangawhai, was recorded as approx 29 0r 30 October (Hansen 2000)
Threats to the New Zealand fairy terns’ survival
Predation —introduced predators such as rats, dogs, cats, hedgehogs and mustelids (weasels, ferrets and stoats) prey upon eggs, chicks and adult birds.
Environmental events such as high tides, storms, and strong winds destroy nests or chicks.
Strong winds and persistent rain can impede the adults’ ability to forage.
Disturbance from peoples’ activities on beaches and in NZFT estuarine foraging areas during the breeding season.
Modification and /or loss of foraging, breeding and roosting habitat.