Nature and conservation
IntroductionRead about the plants, animals and geology you can enjoy along the Milford Road and in Milford Sound/Piopiotahi.
Geology - mountains carved by ice
The Milford Road begins on the ridges of rock debris deposited to the side of a glacier which once filled Lake Te Anau. The U-shape of the valleys and the steep bare walls of hard Fiordland rock (including gneiss, diorite and granite) were formed by the grinding and rounding action of glaciers.
Just before the Homer Tunnel the road enters a cirque basin, carved by ice into a steep walled amphitheatre.
Milford Sound/Piopiotahi stretches 16 kilometres to the open sea and is 265 metres deep in places.
The very high rainfall creates a permanent freshwater layer on the sea surface. Below this layer - stained a tea colour by material washed out of the forest - there is a concentrated 40 metre band of unusual marine life growing on and around the sheer rock walls.
Plants and trees on the Milford Road
Being one of the wettest areas in the country (up to 7 metres of rain per year), the plants and trees are used to rain and snow, especially in and to the west of the mountains.
To the east, the ‘rain shadow’ effect of the mountains leaves a slightly drier environment. On the dry terraces east of Lake Te Anau for example, the fire modified shrublands of manuka, bracken and young beech are very different to the forests to the west of the mountains.
As the road enters the Eglinton Valley the grand red beech becomes the dominant tree, interspersed with important remnants of native grasslands and wetlands.
Beyond Lake Gunn the silver beech trees are stunted because of the harsh climatic conditions.
Mountain ribbonwood, hebe and fuchsia grow on ground laid bare by frequent snow avalanches.
The area around Homer Tunnel offers an exciting glimpse of subalpine plants and native flowers in summer when the snow has cleared. Here alpine buttercups (called Mt Cook lilies) and daisies grow among alpine shrubs and tussocks.
On the descent into Milford Sound/Piopiotahi, occasional native conifers like rimu rise above the silver beech. Tree ferns, under-storey shrubs, mosses and ferns thrive in the wet conditions.
Birds and other wildlife
Walking in beech forest at many of the short walks in the Eglinton Valley (e.g. Lake Gunn Nature Walk), you might commonlfy see small bush birds like tomtits, grey warblers, fantails, riflemen, NZ robins, chaffinches and brown creepers. If you are keen you may spot rarer birds like the endangered mohua/yellowhead or native parakeet/kakariki.
The kea, mountain parrots, are often seen around the Homer Tunnel - watch your belongings though as they are very cheeky! Occasionally on the East Homer Nature Walk you may hear or glimpse a rare rock wren too - they live amongst the large boulders.
Birds are predated by stoats. See the tragic fate of rock wren nests in the Upper Hollyford Valley in this rock stoats eat rock wrens video.
Native long-tailed bats are active around dusk and dawn, near streams and borders of the forest. Short-tailed bats were discovered in the area in 1997, they aren't often seen but may be heard deeper in the forest (they sound similar to a riflemen). The population recovery of both species of bat have benefited from rodent and stoat control in the area.
Whio are being successfully managed in Fiordland National Park.
Conservation along the Milford Road
The beech forests in the Eglinton Valley used to have higher numbers of special species like the endangered mohua/yellowhead.
These birds, and other fauna, are vulnerable to predation by rodents and stoats however. A predator plague hit the valley between 1999 and 2001, reducing numbers dramatically. Since then, DOC has run intensive pest control in the Eglinton Valley to protect native species.
Numbers of mohua have increased since, mainly due to pest control and a successful transfer of new birds (from Chalky Island) in 2010.
The Eglinton River is home to many species including black fronted terns. Their habitat is under threat however, from overgrowth of introduced plants like lupins, and predation from introduced animals.