Some perspectives on New Zealand wildlife and ecology by Rob Hitchcock MCQI

Rob Hitchcock in front of Mt Cook and its glacial lake

After a long period of planning, Jan and I toured New Zealand’s South Island a few months ago. South Island has a reputation as an adventure holiday and nature tourist destination, and it did not disappoint. The backdrop to some of my reflections on biodiversity was the talk by Dr Selwyn Yeoman (A Rocha NZ) at a CRES study day last May.

We witnessed the conflicting demands placed upon the environment by the powerful dairy industry, sheep farming, forestry, adventure holidays and ecotourism. Amidst all of this we noted determined attempts by the Department of Conservation to preserve or reinstate the original flora and fauna of New Zealand, and to eradicate or restrict the species introduced by humans during the last 800 years. You will realise from this that New Zealand tells a complicated story, but it is instructive to those countries facing similar challenges.

The land known today as New Zealand began to break away from the supercontinent Gondwana around 80 million years ago and broke away fully around 65 million years ago. Since then, New Zealand has been in splendid isolation. When it separated from Gondwana, New Zealand took some of the flora, fauna and fungi of the supercontinent with it. South Island features the Southern Alps, including Mount Cook, Mount Tasman and some remarkable glaciers and glacial lakes. The annual rainfall totals are dramatically high in some areas (e.g. 16 metres), creating lush temperate rain forests.

Birds are by far the most prevalent of all vertebrates in South Island. A more than usual proportion are ground feeders, many of which also build nests on the ground. This is probably because of the absence of predators until recent times. The largest New Zealand flightless bird was the moa. When the Maoris sailed from Polynesia and landed in New Zealand in around 1300AD, they successfully hunted the moa for food. So successfully that this giant bird became extinct. There was also at that time a magnificent eagle known as the Haast’s eagle, which was also unique to South Island, and had a wingspan of up to 3 metres. This eagle preyed on the moa, but when it lost its primary food source it too headed inexorably to extinction. This is a case in point for the domino effect of species loss within an ecosystem.

Wax-Eye or Silvereye (Zosterops lateralis)

The Maoris brought with them ship rats, which took a heavy toll on the indigenous bird life. Later on, after the Europeans started to settle the South Island, rabbits were introduced. When these got out of control, stoats were introduced to hunt them. Europeans also brought with them hedgehogs and domesticated dogs and cats, which inflicted a further toll on bird populations. A more recent additional threat to wildlife is in the form of the brush tailed possum. These were originally introduced as part of efforts to launch a fur industry. Some possums were released or escaped, and the rest, as they say, is history. Voracious plant feeders, they will also attack young kiwis and their eggs.

A policy has been introduced, focussed in the national parks, of destroying invasive rodents and possums through extensive poisoning and trapping. In addition, dogs are banned from national parks, with very large fines to back this up. Certain wasp species are also in the sights of the policy. Those who hold that all animals have value to God will be most unhappy with this policy, whilst those whose focus is more on re-balancing of ecosystems and restoration of earlier fauna will perhaps see it as a necessary evil (1). No doubt the need to sustain or increase New Zealand’s large tourism industry and national identity is further motivation.

The story of the tuatara is an interesting one. This attractive lizard-like creature has its own order in the reptile class. They were hunted to extinction by the various introduced species listed earlier, but thankfully some were found surviving on one or two tiny outlying islands. These were relocated to New Zealand where they are subject to captive breeding programmes. We learnt that the only mammalian species that can claim an ancient lineage on New Zealand are two species of bat.

The story doesn’t end with animals. Wilding conifers, also known as wilding pines (there are ten different species included), are invasive trees in the high country of New Zealand. Millions of dollars are spent on controlling their spread. In the South Island, they threaten 210,000 hectares of public land administered by the Department of Conservation. Again, the aim is to restore and protect the indigenous trees and shrubs of New Zealand.

Fjordland Crested Penguin (Eudyptes pachyrhynchus), vulnerable to extinction

Beyond the coastline, biodiversity is as rich as anywhere else in the world. The seas off New Zealand are well known for their whale passageways, although they were not in our area when we visited. We did, however, see Fjordland crested penguins, two species of dolphin, fur seal colonies, red-billed gulls, two species of petrel, and the Manx sheerwater. Oh, and not forgetting the unforgettable albatross.

Rob Hitchcock

Rob is a retired quality consultant with experience in several central government departments, businesses and agencies. He advised them on implementing improved methods of working, and gained expertise in reviewing key functions, projects and programmes. A CRES graduate, Rob is a member of the CRES Steering Committee. He is also a volunteer ranger at Painshill Park, a grade 1 listed landscape.

Photos by Jan Hitchcock

(1) For more on this debate see “Where do Animals Fit in Environmental Ethics and Theology?” By Dr Martin J. Hodson and the response by Prof. David Clough