‘Catch me if you can’

For young kiwi to be raised safely and released, first we need to nab Dad

In early May a group of avid kiwi conservationists gathered at Waiau Camp, deep in the Maungataniwha Native Forest in inland Hawke’s Bay, to search for and catch as many adult male kiwi as they could. Over two days the group used listening techniques, nets and specially-trained dogs to catch 13 birds.

To many, used as we are to images of juvenile kiwi being released into the bush, this business of catching the birds might seem counter-intuitive. But these kiwi catching sessions are a vital part of the ‘circle of life’ that comprises kiwi conservation.

The reason? The precious eggs that are sent to captive facilities for incubation, and the resulting kiwi chicks that are nurtured so carefully until they are large enough to defend themselves from stoats and other kiwi-killers, need to come from somewhere.

That ‘somewhere’ is the nests of breeding kiwi. But how to find these birds, hidden as they are deep in the damp, dark and mossy forests of some of our most remote places?

The process starts with catching adult males and fitting them with a small but powerful radio transmitter. They are then released, back into the areas in which they were caught, free to get on with their lives. And their breeding activity.The catchers target adult males, not females or juveniles, because this property is populated with North Island brown kiwi and, with these birds, it’s the male that incubates the eggs.

Once a bird is fitted with a transmitter, the type of signal this sends will tell conservationists where its nest is and how many days the male has been incubating the eggs. They can then wait for the bird to leave its nest to forage before carefully removing the egg at night for safekeeping.

“It’s far better to take the egg and send it off for incubation and rearing, than for it to be scavenged by a predator,” explains Simon Hall, Chairman of the Forest Lifeforce Restoration Trust.

Fully-fledged chicks released back into the forest after being reared in safety have an approximately 70 percent chance of survival. This survival rate contrasts starkly with the five percent chance that kiwi have of making it to adulthood if hatched in the bush and left unprotected against predators.

The egg-lifting work is part of Operation Nest Egg, the nationwide kiwi recovery initiative that removes kiwi eggs from their burrows, incubates them and cares for the chicks in captivity until they’re big enough to fend for themselves in the wild.

“It’s always nice to read stories or see footage of juvenile kiwi being released into the bush, to start their lives in the wild after having been reared in creches or protected areas,” Mr Hall said. “But in order for that to happen, full-grown birds need to be caught – and this isn’t a part of the kiwi conservation story that many people know about.”

Because paired kiwi are territorial they can be caught at night by humans mimicking a kiwi call. The birds come in closer to locate and expel the ‘intruder’.

‘Kiwi sniffer’ dogs are vital when it comes to searching out the adult kiwi to be caught. Typically, trained volunteers or specialist kiwi catch crews will listen out for the final calls a kiwi makes at night, usually shortly before sunrise. Once these positions have been triangulated the dog teams will be sent into the specific area. At this time of day the scent of the kiwi lies heavy on the vegetation and the dogs are able to home in on the birds. Their training means that this is done with the least possible noise and disturbance. This is called the ‘last call’ technique.

Once located, dedicated kiwi handlers extract the bird, and quickly and efficiently tag it and affix the transmitter. It’s then released back into its habitat and left to get on with its life.

The transmitter and tag do not impede the bird at all. ‘Trail-cams’ and infra-red footage show that the birds forage, sleep and breed just as effectively with equipment as without.

The 13 kiwi caught in May by the Forest Lifeforce Restoration Trust on its property in the Maungataniwha Native Forest bring to 56 the number of birds there fitted with transmitters. These 56 birds, out of a total adult population on the property of “many hundreds”, comprise the pool of kiwi from which the Trust collects upwards of 90 ‘viable’ eggs each year for incubation at the National Kiwi Hatchery in Rotorua and The Gallagher Kiwi Burrow at Wairakei.

The resulting chicks are reared at the National Kiwi Hatchery, the Napier Kiwi Creche managed by Save the Kiwi, or at a relatively new creche at Tangoio near Napier.  

The Trust first started contributing to Operation Nest Egg in 2006. It has now released more than 700 juvenile kiwi back into that forest or into other heavily pest-controlled areas to help re-establish viable populations.