It's a melodious chorus that - with 73 of New Zealand’s native bird species on the World Conservation Union’s 'red list' of threatened species - must be protected.
Since the arrival of man 1000 years ago, two thirds of New Zealand’s native forest has been wiped out, converted to grasslands and urban areas.
Loss of natural habitat, hunting by early settlers and the arrival of animal predators helped extinguish entire species of indigenous birds - up to one-third of land-based birds such as moa, Haast’s eagle, piopio and huia - and left other species seriously depleted.
It's now the goal of both government and volunteer groups, such as the Department of Conservation (DOC) and the Royal Forest and Bird Protection Society, to conserve the remaining natural habitats and eco-systems, and save the wildlife that lives in them.
World leading recovery programmes
New Zealand has become a world leader in bringing species back from the brink of extinction through a series of recovery programmes involving different styles of intervention.
The takahe, thought to be extinct for more than 50 years, then rediscovered in small numbers in the mountains of Fiordland in 1948, is one example of a world leading recovery programme. Takahe and other endangered species such as the kaki / black stilt, are hand-reared in captivity then released into a managed environment.
The fairy tern - New Zealand's rarest bird with only 36 remaining - lives a protected life on sandy beaches north of Auckland.
Species such as the saddleback and the nocturnal flightless parrot kakapo (only 124 left in the world), have been transferred to off-shore island sanctuaries protected from predatory mammals such as possums, stoats, wild cats, rats and deer - to build up new populations.
The recovery of the Chatham Island black robin is another world-renowned success story. In 1980 there were five birds remaining, but today, after moving the only breeding pair to a pest-free island, there are 250 robins in existence.
New Zealand’s national icon the kiwi is not exempt either. In the 1990s, its population was diminishing by five percent annually, prompting the establishment of the Bank of New Zealand Kiwi Recovery Trust in 2002.
Tourism operators around New Zealand are also undertaking conservation measures to help preserve our bird population.
More than 30 percent of New Zealand’s land has been set aside in national parks, reserves and special heritage sites to preserve the country’s ecological heritage.
Many accommodations and lodges, like Mahu Whenua on the edges of Mt Aspiring National Park in the Southern Alps, Tangiaro Kiwi Retreat in the Coromandel and The Farm at Cape Kidnappers in Hawke's Bay, are heavily involved in environmental programmes to eradicate unwanted pests and enhance native forests and wetlands. At both Tangiaro and Cape Kidnappers, DOC monitors kiwi on the property where the bird’s distinctive high-pitched whistle can be heard at night.
Kiwi Encounter in Rotorua hatches and nurtures kiwi before releasing them into the wild, and opens its doors to the public to see this nocturnal wonder of nature.
Willowbank Wildlife Reserve, in Christchurch, works with the New Zealand Conservation Trust and the Department of Conservation (DOC) in the breeding of South Island kiwi species. The wildlife park has also introduced the buff weka, previously extinct on the mainland but successfully breeding on the pest-free Chatham Islands.
In Dunedin, the endangered hoiho / yellow-eyed penguin is the focus of a number of conservation efforts.
Penguin Place is a private conservation reserve, funded entirely through profits from its tour operation. It offers visitors the chance to experience undisturbed penguin activity through a system of covered tunnels through the hoiho habitat.
Elm Wildlife Tours takes visitors to a private conservation area along the Otago Peninsula to see yellow-eyed and blue penguins and 40 other marine bird species. They also fund a conservation project to help boost the population of hoiho.
On the South Island’s west coast, Ken Arnold of White Heron Sanctuary Tours not only takes people to see the majestic kotuku / white heron, but is very active in preserving the bird’s habitat. Arnold maintains pest traps and keeps records on the breeding success of the birds.