Peter Wilson and a team of Landcare researchers have been studying kaka for more than 10 years in a possum-chewed, wasp-infested beech forest near Nelson Lakes National Park.
Wilson monitored 31 kaka for five years. During this time only two pairs attempted to breed and only two fledglings were raised—by one female. A year later, this female was killed, probably by a stoat. He also attached hamster feeder bottles containing honey-water to trees, with the nozzles coming out of poinsettia flowers. Older birds seemed reluctant to try new foods, he says, while younger birds tended to be attracted to novel things.
Have kaka been imprinting on humans, perhaps? Of particular interest to the researchers was the behaviour of a bird nicknamed Knuckle see sidebar; page Soon after the feeding programme began, the year-old bird was taught to use the feeders by his mate. Although supplementary feeding does not trigger breeding, Wilson believes it may put birds in better health, so that when the unknown stimulus urges them to breed, they will have a greater chance of success.
The breeding success of kaka varies from year to year, probably in response to annual variations in food sources. North Island kaka may be more reliant on sap and heavy podocarp fruiting to trigger breeding.
Mating occurs in spring, and the females make primitive nests in deep holes in tree trunks. The nest lining is a mixture of wood fragments chipped and chewed from the inside of the tree. The male returns periodically to provide food for his mate.
Kaka nests only become obvious once the grey, downy chicks reach 10 days old, when the smell of faeces may be detectable from 10 or more metres away. Chicks remain in the nest for 10 weeks, growing adult feathers before emerging flightless and noisy. They can spend up to a week on the ground before their feathers are ready for flight. From the moment the eggs are laid to the time that the chicks can fly is a staggeringly long three to four months—a time when female, eggs and chicks are extremely vulnerable to predation.
It is midwinter and we are in the middle of the expansive Pureora Forest Park, a towering jungle of ancient podocarp trees that constitutes one of the few remaining homes for North Island kaka. Despite Swanndris and balaclavas, we are shivering as we huddle beneath ferns with a team of kaka researchers.
Terry Greene, the crew boss, sits with his head back, eyes straining to see a kaka he knows is perched near the top of a rimu tree. Strung high among these giant trees is an almost invisible mist net. It has taken a full two days to erect the net.
First, a suitable site is selected, where kaka are known to occur, and then a space for the net is cut in the forest floor and all small shrubs and ferns that might entangle the net are removed. After several unsuccessful attempts, a fishing sinker with nylon attached is shot over an appropriately elevated rimu branch at one end of the clearing. The same procedure is repeated at the opposite end of the clearing. A thick rope tied to the nylon is then hauled across.
From this rope, two more ropes hang vertically, with the net suspended between. Once hoisted aloft, the net floats near the top of the canopy, and a pulley system enables it to be raised and lowered quickly. Possums threaten this majestic forest, and the Department of Conservation is using carrots laced with the poison to make a dent in their numbers. The use of is a successful, if controversial method of possum control.
There are fears that the inquisitive kaka could be at risk from eating poisoned baits. Research shows that some kaka, particularly juveniles, will eat baits, but hunger might tempt older birds, too. For the crew, finding even two dozen birds is a needle-in-a-haystack challenge. The monitoring area is 24, hectares, and the birds are wary, unapproachable and can easily fly 50 km in a day.
They also like to play hide-and-seek with would-be captors. High in the rimu, a kaka calls. Greene presses a button on his CD player, and from a speaker hidden up in the trees a recorded kaka call scraarks out.
Above, the real kaka calls again. The CD responds with a whistle. The kaka remains silent, watchful, suspicious. We sit below, motionless in the biting cold, anticipating. Nothing moves. Greene conjures another whistle from his artificial kaka, quieter this time.
Then suddenly the kaka swoops from its perch towards the clearing. It descends, but is still above the net. It clears the top and lands on the opposite side. The thought of capturing a kaka had set the adrenalin flowing. Still, we can hardly expect to be so lucky on our first day when the crew has spent weeks doing this.
The chess game begins again, with Greene playing canned calls on another speaker at the far side of the net. Curiosity rather than aggression brings kaka towards a net, Greene explains.
We move, the kaka moves; we wait, it waits, neither sure of what will happen. The kaka is curious but never flies low enough to chance getting caught in the net.
The net is lowered and carefully packed away. The fine filaments can be easily caught and tangled, creating a mess that takes hours to undo. Catching kaka in Pureora is a military-sized project requiring military-like commitment from the crew, who work in day stints, mostly camping or staying in huts within the forest. They have kg of gear including tents, climbing ropes, harnesses, cookers, slashers, bird-banding gear, mist nets, pulleys, slingshots, tape recording equipment, speakers, a CD player, transmitters, food and packs.
The gear is flown in by helicopter, and a base set up for the crew. Winter daylight is short. Wet and miserable or cold and freezing are the only weather cycles. Greene says some days it is so cold that the bananas freeze inside the hut. About three layers of trousers and six layers of tops just about keep out the chill!
Wellington is the only city with a resident population so it was a great chance to understand how they adapt to life in the city and to investigate how Wellingtonians feel about sharing their city with these mischievous parrots.
Other sap feeding species include Australian sugar gliders and Hawaiian honey-eaters, and of course woodpeckers in North America. If you want some noisy yet entertaining visitors to your garden, the best thing you can do is plant native species that will provide a range of food types across the year.
Check out KC Burns blog link for ideas on the best species to plant. Each black dot is a sighting from a member of the public. These cookies will be stored in your browser only with your consent.
You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary Necessary. Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously. The cookie is used to store the user consent for the cookies in the category "Analytics".
The cookies is used to store the user consent for the cookies in the category "Necessary". The cookie is used to store the user consent for the cookies in the category "Other. The cookie is used to store the user consent for the cookies in the category "Performance". It does not store any personal data. Functional Functional. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
Performance Performance. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Analytics Analytics.
0コメント