Protecting New Zealand’s treasures

New Zealand has many endemic species – species that are unique to a particular place and not found anywhere else. This is not the same as being ‘native’. A species is native if it is naturally found in a particular location, but it may be found in more than one country. For example, the pūkeko is a native species in New Zealand, Europe, India and Asia, but the kākā is endemic to New Zealand. The mānuka shrub is native to both New Zealand and Australia, but the pōhutukawa is endemic to New Zealand.

New Zealand ecosystems have very high numbers of endemic species – 80% of native plants are endemic, 70% of native terrestrial and freshwater birds are endemic, all the native bat, amphibian and reptile species are endemic, and 90% of native freshwater fish found here are found nowhere else in the world. If these species are lost to New Zealand, they are lost to the world.

Native species disappearing

Since humans colonised our land approximately 700 years ago, it is estimated that more than 50% of the bird species have become extinct and more than 75% of the forests have been removed. From the arrival of the first Polynesian settlers and later European settlement, forests have been burned or cut down, species have been hunted for food, clothing and sport, and introduced species such as the kiore, rat, deer and old man’s beard have devastated the natural ecosystems.

Since the arrival of people in approximately 1300AD, it is estimated that over three-quarters of the natural forest has been removed. This removal has meant that many habitats and food resources have disappeared. Combined with hunting, this has contributed to the decline and ultimate extinction of some species. At one time, about 14 species of moa inhabited our islands, preferring a habitat of forest and forest margins. With the arrival of settlers from Polynesia, forest was burnt and converted to grassland and moa were hunted for food – the last moa were lost around 400 years ago.

With a wingspan of up to 3 metres and claws 7.5 cm long, the giant Haast’s eagle evolved to prey on large herbivores such as the moa, but with loss of habitat in the forest and loss of its food source, the Haast’s eagle is thought to have died out about 500 years ago. Since then, another 50 bird species have been lost.

Today, the biggest threat to New Zealand wildlife is habitat destruction and competition for resources by introduced species:

• The impact of the rat on the flightless birds is well known.
• Introduced wasps are destroying the resource of honeydew in native forests.
• Cats prey on a range of birds and insects – the last ever Stephens Island wren was eaten by a pet cat.
• Introduced plants clog waterways and compete with native species.

Our conservation challenge

Our species are special, with many of them still unknown and undiscovered, and New Zealand faces a huge conservation challenge. The government and scientists are working together to form strategies to preserve our hidden treasures.

One strategy is to create protected ‘islands’ where predators have been removed and are prevented from returning. Some are actual islands at sea, out of reach from reinvasion by predators such as rats, stoats and cats. Others are located on the mainland, such as Zealandia in Wellington – these onshore or mainland ‘islands’ are fenced in special netting and monitored for the invasion of predators.

On both onshore and offshore islands, threatened species like the kiwi, the tuatara and the wētā can be protected to live and breed successfully.

For many species, it is a race against time. Trying to preserve entire ecosystems is difficult but necessary if the amazing range of species endemic to New Zealand are not going to be lost forever.