environment

Mingling with the endangered and elusive

On a walk through the spectacular wildlife sanctuary on Tiritiri Matangi Island, Suzanne McFadden discovers a success story – especially for one unusual kokako.

To put it politely, I was peeved.

In the heat and heavy humidity that was a portent of the first summer storm of 2018, I was stomping down a dirt track through the middle of Tiritiri Matangi Island, desperate to spot more rare birds in this predator-free jewel of the Hauraki Gulf. I felt that my husband (bless him) was leading me down the wrong dusty path.

But then I stopped, threw a hand up in his face, and whisper-hissed: “Don’t move!” In the fork of a tree, barely 10 metres away, was the silhouette of a primordial-looking bird – larger than a tui; sleeker than a kereru. “Kokako!”

Our guide earlier in the day couldn’t hide her delight when she saw one of these endangered, and often elusive, native birds hop across the track in front of us. All we caught was the last of his tail feathers.

The writer's journey of discovery on Tiritiri Matangi Island. Photo: Eugene Bingham

Now on our own, there were three North Island kokako calmly going about their business on the edge of the Cable Track. For the next 10 minutes, the masked choristers of the New Zealand forest allowed us to stand and watch them, eating coprosma berries, preening themselves and making clicks and comforting calls of “took” to each other.

The brashest of the birds was Poutama; his wife, Tiara, was hopping from branch to branch above him. Crashing around somewhere in the undergrowth was their yet-to-be-named offspring, a fledgling who had just left the nest a week before.

How did we know all this? We didn’t, initially. But through my flurry of photographs, I was able to identify Poutama by the coloured bands on his legs: orange and metal on the left, white on the right.

That’s why this 220-hectare island sanctuary is so special. Not only is it a nursery helping threatened species – like kokako, hihi (stitchbird), tieke (saddleback) and takahe – to recover, it’s also an open scientific reserve that gives humans the chance to see them closer than they might imagine.

Poutama, with bands visible on his legs, eating coprosma berries. Photo: Suzanne McFadden

Native soap opera

Almost all of the 40-odd kokako who live on Tiritiri Matangi have been given unique banding codes and their own names. Most are in stable relationships, although some have life stories that could rival the scripts of Shortland Street.

Poutama has his own fascinating story to tell, as related by Morag Fordham, the kokako team leader on the island.

For years, Poutama was the social outcast of Tiritiri. He arrived back in 2008, having been born in captivity at the Pukaha Mount Bruce National Wildlife Centre in the Wairarapa.

He’s 17 now – a senior citizen of the island community. And yet, he’s only just found the love of his life. A long-term bachelor, Poutama was often seen in the company of female kokako, but couldn’t seem to clinch a mate. This was not usual behaviour for a kokako.

The grand Poutama. Photo: Suzanne McFadden

Part of his problem, Fordham believes, was his appearance. One of Poutama’s bright blue wattles – the fleshy pads at the base of his bill – would often deflate. In Maori legend, the kokako carried water in his handsome wattles to help Maui battle the sun.

“That certainly didn’t add to his ability to mate,” Fordham says of Poutama’s disfigurement. “But since he’s been with Tiara, he’s had no more problems in that area. He’s a good-looking bird now. Married life obviously suits him.”

Tiara was a two-year-old bird when she took pity on the inexperienced male back in 2015. “He’s turned out to be a fabulous dad, which is amazing because he was so socially inept in the kokako world.” Fordham says. “We’re so pleased to see him come right.”

Despite his failings in avian society, Poutama has never had a problem mingling with humans. He’s been known to delight visitors arriving on the island with his haunting, melodious call.

Fordham: “He doesn’t care that you’re there, he just eyeballs you and carries on with life. He’s a particularly good bird for advocacy.”

That’s a large part in developing the kokako population on Tiritiri Matangi – promoting the species. Fordham estimates there are 42 birds on the island, not counting this season’s chicks. They won’t be tallied until they are fledged and sighted during the winter.

“We think the population is looking pretty healthy here. Tiritiri mostly plays an advocacy role with the public, who can be sitting in Wattle Valley when a kokako flies down and takes a bath in front of them. They’re stunning birds, with their blue wattles and black masks, and their call is quite spectacular.”

A piwakawaka, or fantail, after a bath in the water trough on the Wattle Valley track. Photo: Suzanne McFadden

Tiritiri Matangi is also playing a critical role in boosting kokako populations throughout New Zealand. Once considered a threatened species, the North Island kokako (once known as the blue-wattled crow) is now classified as “at risk, but recovering”. There are around 1600 pairs nationwide.

(As an aside, the South Island kokako, with its distinctive orange wattles, has not fared so well. Once thought extinct, it has been reclassified to “data deficient”; a $10,000 reward awaits the first person to present concrete evidence that the bird still exists.)

Twenty North Island kokako were translocated off Tiritiri last year, and released in the 1300ha Parininihi Forest in Taranaki. It was a pivotal and poignant moment in the revival of kokako – the last remaining kokako in Taranaki, a male bird named Tamanui, had been removed and placed in a captive breeding programme run by the Department of Conservation 18 years earlier. His offspring were brought to Tiritiri in 2007, in the hope that their descendants would one day return to a predator-free part of Taranaki.

“Six pairs have formed and had chicks there this season. It’s a great start,” says Fordham, who hopes a similar translocation can be made this year to Mt Pirongia in the Waikato, which began re-establishing kokako last year.

The curse of isolation: inbreeding

The test at Tiritiri Matangi is to widen the kokako gene pool. Inbreeding is an ongoing problem in small isolated bird populations, as Jan Wright, the former Parliamentary Commissioner for the Environment, noted in her report Taonga of an island nation: Saving New Zealand's birds, released last year. She even used the example of two kokako on Tiritiri Matangi: a young male named Bandit who was “consorting with his grandmother”, Cloudesly Shovell (who at 21 is the oldest bird on the island, and perhaps bearer of the best name).

“This may be a happy relationship, but it is unlikely to be a healthy one,” Wright wrote. “We must guard against our birds drifting to the shallow end of the gene pool.”

Young wetapunga (giant weta) have been re-established on Tiritiri Matangi, along with tuatara, Duvaucel's gecko and shore skink. Photo: Suzanne McFadden

Fordham says her group is trying its best to bring new genes onto the island. Three males – Waipapa, Rimu and Slingshot – came from Waipapa, in the rich rainforest of Pureora near Te Kuiti, and now all have partners.

But introducing “foreign” birds comes with its own complications. Dialect is an issue.

“Birds from Pureora seem to be slower at finding mates because they sound just a wee bit different. Kokako are inclined to stick together in their own groups. Just like people with accents,” says Fordham in her distinctly Scottish lilt, “the birds have to learn the local dialect.”

There’s also the opportunity to swap eggs from other nests around the country. “We’ve tried one egg-swap on Tiri which was unsuccessful; the fledged chick disappeared. But the Hunua kokako project ended up with two chicks from Tiri. The difficulty is in synchronising the nests, but we’d like to do more of it to help with our genetics,” she says.

“But honestly, as long as we don’t start producing two-headed birds on Tiri, I don’t think it’s too serious. All the chicks so far have been perfectly healthy and able to reproduce.”

Which takes us back to Cloudsley Shovell. Named after a British naval admiral (her gender was obviously confused early on), she was one of the original founding kokako on Tiritiri – along with four brothers from the Mapara region of the Waikato.

Toutouwai (North Island robin) are another rare native bird species recovering on Tiritiri. Photo: Suzanne McFadden

She found a love-match with one of the brothers, Te Koha Waiata, and together they happily produced 23 chicks over 17 years. That was until grandson Bandit recently broke up the couple, and moved in with Cloudsley Shovell. They had one chick together, before the busy-body Bandit flew straight into the mist net and was relocated to Taranaki.

Within 24 hours of Bandit’s departure, Cloudsley Shovell had formed a new relationship with Hemi – another of her grandsons.

Fordham spends up to three days a week on the island, monitoring the sometimes quirky behaviour of the local kokako. She’s seen males uncharacteristically build nests for their partners (often being scorned for their efforts), and recently two females have used nests that were built for other pairings.

“Some birds have a wandering eye, like Miharo,” she says. “I wouldn’t trust him as far as I could throw him. His partner, Mere, was sitting on the nest, while he was busy chatting up Royal.” Mere has since been moved off the island, but, within a couple of days, Royal had moved in with the philanderer.

“We know these birds quite intimately, but bear in mind that we humanise what we see. It may be a load of rubbish, but from what we can see, that is what’s happening. Scientists might tell us otherwise. But they are our personal observations, and for us, it just makes common sense.”