Liz Light visits Westland's kotuku colony.

Okay, I confess, I'm crazy about birds, so seeing the rare and exquisitely beautiful kotuku (white heron) has been high on my wish list.

Visiting them in spring in their breeding colony, when the birds are ostentatiously displaying their fine fan of white nuptial plumage and have fluffy chicks on nests is a primo experience.

Kotuku have only one New Zealand breeding site, on the remote Waitangi Roto Stream in Southern Westland and White Heron Sanctuary Tours, at Whataroa, is the only company permitted to take visitors there.

The journey to the herons is an unexpected bonus. A throbbing V8 jetboat skims us down the Waitangitaona River for 20 minutes, the driver hunched over the wheel with a grin of a man who loves what he does and his foot firmly on the throttle. The speeding boat thunders along the straights, slips around corners, blows my eyes wide open and tugs at me with g-forces.

Then we get on a slow boat and head up the Waitangi Roto Stream, passing through New Zealand's biggest and best kahikatea forest. Kahikatea, or white pine, stand straight and tall above the rest of the trees and thrive with their feet in water. A 500m walk takes us through true rainforest with every tree supporting myriad vines, ferns, mosses and tiny orchids. I want more time here but am busting to see kotuku so I hurry along the path to the hides opposite the nesting site.

The bright white kotuku, graceful, 1m high with long thin legs and black knife-shaped beaks, have woven nests of sticks in precarious places.

The colony of 42 nesting pairs has been joined by 45 spoonbill pairs and twice as many little shags are nesting. There is safety in numbers and spoonbills and shags know the sabre-like beak of the kotuku will lacerate predators hawks, weasels and stoats in a flash.

It's busy here with all these nesting birds squeezed into a 70m-long area of forested riverbank. The birds fly in and out, fishing to feed their chicks. Some argue noisily over territory and chicks have sibling disputes over who gets fed first.

I watch kotuku courting, displaying their plumes like peacocks, curling their necks and clacking their beaks together. They fly elegantly, wings wide and their long necks stretched forward. But they land with copious wing-flapping and ungainly wobbling.

The chicks are initially cute fluffy things that do nothing but sleep and eat. When they are little, one parent stays guarding the nest while the other finds food. Later, as they grow bigger and hungrier, both parents look for food in the extensive fish-filled shallows of nearby Okarito Lagoon frantically foraging for their demanding kids.

I watch the antics in this maternity ward and nursery school until I'm dragged away. The continued existence of kotuku is a credit to the Department of Conservation's efforts over the years.

There were only four breeding pairs left in the 1940s because, for nearly a century, their feathers were in demand to decorate women's hats. They were hunted ruthlessly and, as well, eggs and chicks were predated by introduced mammals such as weasels and stoats.

It's a privilege to see them. Maori believe kotuku are sacred and symbolise all that is rare and beautiful. I agree.

White Heron Sanctuary Tour: Phone 0800 523 456 or see

Where to stay: Te Waonui Forest Retreat is an award-winning and extremely comfortable luxury lodge, with a feeling of being immersed in the West Coast rainforest.