With the hunter and the hunted

A DoC worker holds a karearea chick who is being monitored for progress. Picture / Alan Gibson

Wings scooping the air to pick up speed, the female falcon comes in to attack at eye level, a speckled-brown dart of fury aimed straight at the scientist's blue canvas hat.

The heavy thud as she strikes is loud, astonishing.

Immediately she sweeps up into the air, her shrieking cry echoing over the valley, jangling the nerves.

This is the front line of New Zealand falcon, or karearea, research and it is not for the faint-hearted - or the hatless.

To reach this nesting site, we have driven for more than an hour in a sturdy four-wheel-drive truck over narrow, treacherous dirt tracks deep into a Bay of Plenty pine forest. We arrive at a small, steep-sided valley with row upon row of baby trees growing over rugged land, the ground littered with the wood debris of past harvests.

The man in charge of this falcon research project, ecologist Richard Seaton, and his two student volunteers, Matt Clement and Shane McPherson, hand out various pieces of unattractive headgear. McPherson is already wearing what looks like a tea cosy on his head and Clement is grinning knowingly.

This site will be a doddle, they say. They had decided earlier not to take us to "blood gully".

An old yellow panama hat pulled from the pile in the back of the ute shows dried, dark spots of red.

With panama firmly on head, I clamber after Seaton down a steep ridge into the small valley below. The Herald photographer has embedded himself at a safe distance on the ridge, declining Seaton's invitation to come any further.

By now two brown birds are circling suspiciously overhead. The larger is the female falcon, he says, the smaller is the male.

By the time we get close to the nest at the base of a tiny pine, the mother bird has launched a full-on aerial assault, dropping down to eye level at the far end of the valley and coming straight at us. Stupidly - and fleetingly - you think she might not be quite as serious as she appears.

But she is deadly determined, her fierce concentration both awe-inspiring and unnerving.

Her first few divebombs are successfully fended off with a quick flick of the hands upward at about eyebrow height, a trick Seaton has shown me as we trekked to the nest.

But as he turns his back on the female to take the two chicks - and with his cowardly accomplice prudently dropping back - the furious bird thumps into his head.

Her cries are blood-curdling as she shoots up into the air, flies away and then back again, talons making contact with Seaton's head a second time.

He is getting the young birds into drawstring calico bags and finally we scarper back to the safety of the truck, the chick-napper's shaven head streaked with blood under the hat.

"Oooh, that hurts."

Seaton, a quietly confident 28-year-old Englishman, will likely spend his working life among these birds and others of their kind, seeking answers to questions that hang over their long-term survival.

"It's a wonderful study site, it was a bit of a godsend to find this population," he says. "This forest seems to be managed quite well for falcon and we need to find out why. Mostly we need an idea of what affects these birds, the level of predation and chick survival rates."

While karearea are pictured on the back of every $20 note, the loss of vast tracts of their range means they are seldom seen by New Zealanders.

The more commonly sighted Australasian harrier, or hawk, is often assumed to be New Zealand's only bird of prey but the falcon is the true native, smaller and more ferocious, with longer, more pointed wings, longer legs and a longer tail.

Both birds are members of the fearsome raptor family which includes eagles, kestrels and kites, some of the fastest birds on earth clocked at speeds of up to 230km/h.

Karearea are not quite that fast but are expert flyers and fiercely territorial.

Research in the 1970s by New Zealander Nigel Fox concluded they were the most aggressive falcon in the world.

With long talons, a notched "tooth" on the beak to break the neck of prey and eyesight up to six times better than ours, they are New Zealand's premier winged hunter.

"They're the only New Zealand bird that can give predators a bit of what-for," Seaton says.

"It's nice to come across a New Zealand bird that can get its own back."

But their fearlessness hasn't saved them from threatened status. Falcon chicks are vulnerable to attack from stoats, possums and even magpies and the birds have suffered from a gradual loss of their preferred lowland native forest habitat.

They have adapted by living in pine forest. This nest is in Kaingaroa Timberland's 140,000 plantation outside Murupara, a stronghold for karearea. The surprisingly high 20 nests identified last season could rise to 30 this season.

It's a myth pine forests are "ecological deserts", Seaton says. This one is teeming with falcon prey, including skylarks, quail, tomtit and finches. The birds also kill small mammals such as rabbits and hares but unlike the harrier, rarely eat carrion.

Seaton wound up here after following his Kiwi girlfriend home when the pair met in Mauritius, off Africa, three years ago.

He was studying the Mauritius kestrel, a bird of prey brought back from the brink of extinction after its population dropped to just two pairs in the 1970s.

One season's research for this project is finished, this season's work is about half-way through and he has another to go. The field work is 12 hours a day, seven days a week for six months of the year.

"A lot of people tried to put me off studying falcon, they said it wasn't good for a PhD because of small sample sizes, but I like a challenge."

It's their beauty and fierceness that attracts him, he says, the excitement and glamour that attaches to that elite group of top predators that includes the lion and the leopard.

"Apart from being beautiful birds, they are incredible to watch," Seaton says.

"I saw a magpie being attacked by one the other day, feathers were flying but the magpie got the worst of it."

As part of his work, Seaton handles a brood of 26-day-old chicks.

The young birds have a characteristically haughty falcon look, with long, hooked beak and great wide staring eyes, but their wisps of grey baby fluff make them look more comical than savage.

"They're thinking 'when I'm older I'll get my own back"', Seaton says.

The chicks are measured and weighed and a blood sample taken from under one wing for a genetic research project at Wellington's Victoria University.

"If you're going to stress them out, you might as well get as much data as you can," Seaton says.

He is organised and meticulous but the three men banter and joke their way through the work. Attaching a metal band to the chick's legs is a delicate procedure using bulky pliers near those tiny, soft greyish blue legs. Breaking a leg "would be your worse nightmare", Seaton says.

The chicks are surprisingly placid, a result of their male gender, apparently. Female chicks - along with their adult counterparts - tend to be more aggressive. The female adult is also generally larger than the male.

Falcons lay between two and four eggs during a breeding season that lasts from October to February, the female doing most of the feeding for the first few days while the male hunts, making "food passes" to her from the air. The female will turn upside-down in flight to take prey from his talons and the birds can turn on a dime, Seaton says.

By next week these chicks will take their first flights, the parents dropping food and dive-bombing them in mid-air to hone their flying skills and get their fitness up.

Early observers mistook the behaviour, thinking the adults were attacking their young.

By 50 days the juveniles will begin hunting for themselves, although the adults continue to feed them for some weeks.

Karearea swoop on prey from behind a tree or other hiding place or attack from on-high. The hapless victims are grasped in their claw-like talons in mid-air or on the ground and finished off by a swift bite to the back of the neck.

Clement and McPherson have been collecting "prey items" during this trip, a sorry little clutch of tail feathers the only thing left from a falcon meal.

Three species of the birds have been identified in New Zealand but research to show any genetic differences has not been done.

These birds of the Kaingaroa are "bush falcon", found in the North Island and northwestern South Island.

"Eastern falcon" are found in the eastern South Island and the "southern falcon" in coastal Fiordland, Stewart Island and the sub-Antarctic Auckland Islands.

Fully protected since the 1970s, karearea are listed by the Department of Conservation as threatened but just how threatened, no one knows. The North Island population estimate is around 400 pairs.

"We don't know if the population is stable, increasing or decreasing," Seaton says. "The Department of Conservation has classified them as threatened, in gradual decline, but in the medium-term they are at risk of serious decline."

This project will eventually involve radio-tracking 10 juveniles, looking at where they set up territories, how they use the pine forest, prey abundance and density and how they respond to predator control.

Seaton lives on a $25,000 Enterprise New Zealand grant, half paid by Massey University and half by Timberlands - which also provided the four-wheel-drive.

Money for the radio-tracking, each tracker costing $4000, has been scraped together with donations from various groups involved in protection and advocacy for birds of prey, such as the Raptor Association and Wingspan in Rotorua, and conservation lobby group Forest and Bird. Some of the radio-tracking equipment has been "begged and borrowed", Seaton says.

The three men flat together in a "volunteer" house next to the DoC area office at Murupara.

"The DoC helps where it can but as far as money goes, it has other priorities," he says.

Seaton will eventually leave New Zealand to work on other raptors around the world, but says he will return at regular intervals.

"Once you have done your PhD on a species, they get under your skin and with my partner's family being Kiwi I will always come back here."

"I want to be able to influence what happens by doing this project, to make recommendations on long-term conservation policy.

The idea is that this is the first study of many."

Hats in place, Clement and McPherson return the chicks to the nest and escape serious harm, cause for some boasting as they clamber into the truck.

The only sound as we drive away is the whisper of the wind through the forest and occasional bird call.

The male falcon watches us leave from a perch high in a nearby pine, the female is nowhere to be seen.