Predators introduced by man batter iconic species
Hyperbole is simply not part of the equation when it comes to the decimation of New Zealand’s iconic Kiwi.
From a population of 12 million about 200 years ago the Kiwi population had been reduced to 68 000 by 2019.
New Zealand’s iconic bird is in danger of disappearing altogether from unmanaged conservation areas, where populations are declining at the rate of 2% per year.
Enigmatic Mother Nature dealt New Zealand a royal flush 80 million years ago when the hulking continent of Gondwana split up. New Zealand drifted away as host to a glorious population of birdlife while all manner of nasty predators was left behind on the hulking island of Australia.
The intrusion of man 900 years ago into the pristine bird paradise heralded the start of an attack on endemic species that continues to this day.
The attack has grown in intensity over the years to the point that since human settlement the number of species that have become extinct in New Zealand includes a bat, at least 40 birds, three frogs, three lizards, a freshwater fish, four plant species, and several invertebrates.
Focused conservation efforts are underway to turn around the decline of a host of threatened fauna and flora, including the threat to the Kiwi, a nocturnal, flightless bird that has whiskers like a cat. The defenceless bird gives away its position to predators as it sniffs loudly through nostrils at the end of its beak and its taps the ground searching for food.
The New Zealand Department of Conservation (DOC) has created several land-based Kiwi sanctuaries across North and South Island. Offshore islands dedicated as kiwi sanctuaries have been set up while various community-led projects (many of them sponsored by the Kiwis for kiwi organisation – see bit.ly/3y9846E
By far the majority of threats https://bit.ly/3fdfD4P that could lead to the extinction of the Kiwi and other wildlife can be attributable to man. Not only do we destroy natural habitat, but we also introduce predators like stoats and bring in domesticated animals such as cats and dogs whose instincts are to hunt.
Around 70% of Kiwi deaths are attributable to stoats. Kiwi killed by cats, just like Mum’s favourite tabby that arrives with a trophy sparrow in its jaws, are included in that total. Unleashed and trained hunting dogs have taken and continue to exact a heavy toll on the Kiwi population, as do pigs, rats, possums, hedgehogs and weasels.
Only 10% of Kiwi chicks live longer than six months and of that total only 5% achieve adulthood.
The DOC tells us that all Kiwi species are in trouble to some degree and backs that claim with figures of each of the 11 Kiwi taxa. The Rowi and Haast tokoeka are listed as nationally critical with all four of the Brown Kiwi taxa in serious decline. The Northern Fiordland and Southern Fiordland tokoeka, as well as Stewart Island tokoeka and Great spotted Kiwi, are in gradual decline while the Little Spotted Kiwi is range-restricted.
DOC says Little Spotted Kiwi are on the road to recovery while the population of Rowi has increased, mainly due to Operation Nest Egg™.
Most chicks on the North Island are hatched at Kiwi Encounter in Rotorua and Auckland Zoo. The West Coast Wildlife Centre focuses mainly on New Zealand’s two most endangered kiwi species, rowi and the Haast tokoeka.
The focus on survival interventions was upgraded after 1994 to enhance techniques that included collecting, transporting and incubating Kiwi eggs. Delicate techniques were needed to ensure that young chicks were fed and kept alive in captivity.
Chick survival rates through the implementation of Operation Nest Egg have reached 99%. New programmes are being set up, mainly in unmanaged areas, to turn around the decline in Kiwi populations.
My natural curiosity prickled, I wanted to experience first-hand the procedures in place at Operation Nest Egg. As luck would have it, my New Zealand home town of Rotorua is the site of the Kiwi Encounter https://bit.ly/3kOoOfw at the Rainbow Springs Nature Park.
Emma Bean, Kiwi Husbandry Manager, National Kiwi Hatchery, swapped working with elephants in Chang Mai, gibbons in Phuket and reptiles in the United Kingdom to focus mainly on embryological aspects of the Kiwi.
‘Nothing beats working with Kiwi,’ she remarked when I met her ahead of her demonstrating how a recently hatched Kiwi chick is trained to adapt its feeding habits to accept mushed ox heart.
The egg incubating and newly hatched chick stabilising area is run on scientific lines with strict hygienic protocols in place. Members of the public can observe, through hermetically sealed viewing glass panels, staff candling eggs using specially developed torches. Candling takes place every few days to monitor the development of an egg. This allows conservation staff to age an egg within 1–2 days of its actual developmental stage. Observers can also watch chicks being fed by hand.
Emma collected a chick from its temperature-controlled enclosure, weighed the bird and sat down on a chair to begin the laborious feed training process. The chick, whose gender will not be identified for a few weeks, emerged from the incubated egg weighing 272g before Emma patiently coached it to eat 14g of ox heart over 10 minutes.
Emma is remarkably pragmatic about the plight of the Kiwi but exudes a measure of confidence that the national strategy to save and grow the Kiwi population will meet with success.
Clear out all predators and manage the birth and growth of Kiwi from egg to near-adult size and weight before returning them to the wild.
‘There are only two ways to look at it: all predators have to be cleared out but at present, that means predator-clear offshore islands (the best known of which is Kapiti), or an entire area has to be cordoned off with a pest-proof fence and a haven created for endemic species (captive management of Kiwi).’
‘The other option is Operation Nest Egg, which is a Kiwi egg recovery programme,’ says Emma.
‘Male Kiwi in the wild are fitted with monitors. Since the male is responsible for sitting on an egg, once the male stops moving around it can be presumed that he is sitting on the nest. The field workers collect the egg or eggs (up to two per clutch) after 60 days of natural incubation.’
She says that ‘Kiwis are hatched with everything in place, they are miniature adults and therefore need very little parental care. The chick has a yolk in its tummy so can feed off that for about a week. Evolutionary-wise this was good in the old days but a recently born chick at 350g is just not big enough to battle a stoat.
‘It takes us about two to two and a half months to get a chick’s weight up to around a kilogram but in the wild, this weight gain takes up to six months. That’s far too long to avoid being attacked by a stoat and hence the high attrition rate in the wild.
‘Chicks lose weight for the first week or so of life as they utilise their yolk, but they then start gaining weight as they are established onto solid food. Once they have regained their natural weight, they are transferred to our outdoor enclosures where they are weighed weekly. The outdoor run mimics conditions in the wild but the chicks are also provided with supplementary food.
‘After about two to 2.5 months the chicks are returned to the areas from which the eggs were taken. This practice means that the Kiwi population in each area will continue to grow,’ says Emma.
She remarks that Kiwi Encounter has a 95% success rate in hatching chicks that make it through to the incubation room.
As I drove away from Rainbow Springs, New Zealand one-dollar coins imprinted with the Kiwi tinkling in my pocket, I reflected that the toughness and endurance of the New Zealand people – affectionately known internationally as Kiwis – are being transferred in no small measure onto the extensive ‘Save the Kiwi’ programme.
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