Conservation in New Zealand
New Zealand has fascinating and unique conservation issues. It was the last land sizeable landmass to be settled by human beings after being separated from Australia for 70 to 80 million years. This time of isolation allowed unique forms of bird life to evolve in the absence of mammalian predators. When the Maoris arrived in about 1250 AD the only mammals were three small species of bats. What had evolved was a range of birds that filled all the available niches. There were ten species of Moa that occupied the niches of mammalian herbivores elsewhere. The Adzebills where flightless avian predators and Haast's eagle, which was the largest eagle ever to evolve, preyed upon the Moas.
There were and are a range of of other unique species. The sad fact is that within 150 years the Maoris had caused the extinction of the Moas and in total 28 species and since then Europeans have caused the extinction of a further 23 species. The Maoris did it by introducing the Kiore (Maori rat) and Kuri (Maori dog) and by over hunting and use of fire. They cleared a quarter of the native forest. Europeans did it by reducing the native forest to twenty percent and by introducing predators.
The worst predators are the Common Brush-Tailed possum and the stoat but there are also feral cats, ferrets, weasels and dogs. The changes wrought are enormous. In the farmland there are only a few native bird species the vast majority are an odd sub-set of European birds - Blackbirds, Song Thrushes, Sparrows, Dunnocks, Yellow Hammers, Sky larks, Red polls, Goldfinches, chaffinches and Greenfinches. The Australian Magpie is quite common. The European birds were introduced by so called 'Acclimatisation Societies'. It could well be that if they had not, there would be virtually no birds in the agricultural areas as the native birds rely on the native vegetation. The European birds do not seem to have caused huge conservation issues but the predators have been devastating. The possum was introduced by people hoping to make money from the fur. It found itself in heaven and as it is omnivorous and arboreal it has managed to eat the native vegetation and native birds. There may be 70 million possums in New Zealand. They represent the commonest road kill seen as you drive around. The next great scourge is the stoat, introduced to reduce the rabbit numbers which in turn were introduced for food. The stoats did little to reduce the rabbit population but were very partial to the native birds. These days the New Zealand authorities are hyper-aware of the foolishness of introductions. The Department of Conservation is working feverishly to protect native fauna on Island fortresses like Tiritiri Matangi near Auckland and Kapiti Island near Wellington. Here they have eliminated the stoats by trapping and the rats by poisoning with the controversial 1080 poison. In other places sophisticated fences are used to keep the predators out. It works, but the expense and effort is enormous and these little bastions against extinction are a sad reminder of what has been lost over a land area which is greater than the UK. There is a dream that some day predators can be eliminated from the whole of New Zealand by the use of 'virtual fences' which are trap lines turning the country into a jigsaw of predator free areas.
The last bird species to be lost was Stead's Bush Wren in 1972. Can the Conservation Department hold the line? The fifty one species lost were unique to New Zealand and so it is a loss for the whole world. Reptiles are also at risk. The Tuatara is still with us, just.
Good luck chaps!
Oh, and the Monarch Butterfly has been introduced from America. If the mind had any boggling capacity left, it would boggle.