A bird in hand
The Defence Force and Department of Conservation are unlikely allies in the battle to bring one of our most endangered species back from the brink, Hannah Martin writes.
Nestled at the entrance to the Kaipara Harbour, New Zealand’s rarest bird shares its home with the Royal New Zealand Air Force weapons and bombing test site.
Only 40 fairy terns remain, and six of them live at the Papakanui Spit, off Kaipara South Head, northwest of Auckland.
Terns are thought to have once lived along the coasts of the North Island, and on the northeastern part of the South Island, but now they are only found in only four places in Auckland and southern Northland: Kaipara, Pakiri, Mangawhai, and Waipu.
The species might be New Zealand’s most endangered, things have been worse for the tiny bird of the white body, light blueish-grey wings and the eyeliner look – there were only three pairs in 1984.
The population didn’t improve much in the 1990s – fairy tern numbers barely scraped into double digits.
Since DOC began its nest protection programme, the number of fairy terns has risen from that low of just three breeding pairs up to 12 pairs this year.
Ayla Wiles, a fairy tern godmother in khaki, has been living on a Defence Force base since October.
As fairy tern warden for the Department of Conservation, Wiles spends her days ensuring the six birds at Papakanui Spit have the best shot at breeding, hatching and fledging chicks,.
She watches and waits for the birds every day, searching for nests, locating eggs and checking predator traps.
Her day starts at the range warden base. From there she makes her way down to the spit, the 4WD bumping and trudging down dirt tracks through Woodhill Forest to the beach. The car has to stop twice to let wild deer pass.
Ominous signs appear: ‘‘Defence Force Weapons Training Area – Trespassers will be prosecuted’’.
There’s a lot of pressure involved in locating the eggs and getting them to hatch, Wiles says.
‘‘They’ve just got so many things working against them out here.’’
And from a lookout over the dunes and the Papakanui Spit, the challenge of finding the birds would seem overwhelming.
But now that the breeding season is winding down and Wiles just has one chick to mind, some of the weight has been removed from her shoulders.
Wiles, who has a masters degree in conservation biology, will stay until February, when the chick can fly – after that, her work is done.
But reaching that milestone won’t be easy.
Despite there being only six terns at the Papakanui, they’re incredibly territorial and nest kilometres away from each other – which makes monitoring tricky, Wiles says.
This breeding site is far worse than the others. The spit is exposed to the west coast conditions – the wind whips the dunes constantly, moving nests and burying eggs, and a king-tide could sweep in and wash nests away.
But Wiles is on their side. If a nest is badly sited, she will sit by it for an entire day, moving it as little as one metre an hour, trying not to disturb it too much.
Anything more than that, and the tern could lose the nest entirely, she says.
‘‘You’ve gotta stay one step ahead of the dune. It’s really rewarding to get an egg after all of that.’’
Terns often come to feed on a nearby marshland, but not today.
The chicks depend on their parents for the first year of their lives, and it takes them a long time to become independent, Wiles says. ‘‘It’s incredibly hard for a human to teach a bird how to fish,’’ she jokes.
Despite population numbers being dire, fairy terns can live to 19 years old. The oldest bird at the Kaipara site, Bertram, is 13, and his son and ‘‘grand-chick’’ nestnearby.
Infertility is an ongoing issue thanks to the low numbers.
‘‘Because there are so few birds remaining, they’re inbreeding, creating a mutation in the genetic line,’’ Wiles says
Though they’re trying to repopulate, they often aren’t fruitful. Of 22 eggs laid this season, 10 were infertile, six were lost to predators and six hatched.
The only chick still at Kaipara arrived on January 12. The other two eggs were given to ‘‘foster’’ parents and moved to Mangawhai and Waipu.
Further down the spit, terns have made their nests in shell patches on the sand. They disguise their small white eggs close to the surface in a pile of crushed shells.
But the adult birds are still nowhere to be found.
The other breeding pair at the spit are nested in a ‘‘terrible’’ spot this season, according to Wiles. They just pick their spot and that’s it, she says.
‘‘Because of humans and predators there’s really just nowhere else for them to go.’’
Nearby Woodhill Forest is a haven for pests and part of her job is maintaining and checking traps daily. The endangered bird’s enemies include stoats, ferrets, weasels, hedgehogs and rats.
DOC have made a ‘‘trapping halo,’’ which starts 90 kilometres away from the nesting area, but some predators still make their way down to the beach.
She says they’re lucky at Papakanui that people don’t have access to where the terns live which is a major issue in Mangawhai and Waipu – where they nest in open, public beaches.
‘‘You can fence areas off, but people still walk through nests.’’
The Defence Force might seem an unlikely ally, but Wiles says having the terns nest in a Defence Force protected area gives them a better shot at survival.
‘‘I’d much rather have the Defence Force own the land than have it be open to the public.’’
Defence avoids weapons tests around breeding season, and stay well away from the spit.
Wales has an unusual job – one that gives her space from civilisation and a lot of time alone in the fresh air.
But that’s not a bad thing, she says. After a day trying to track down these elusive birds, with no luck, it’s clear they keep too busy for her to ever get bored.
They’ve just got so many things working against them out here. DOC warden Ayla Wiles