he boundary between Auckland and the Waikato is marked by the Bombay Hills, which lie 45 kilometres south of the city centre. Bombay itself, named after an immigrant ship, is a small farming community in an area dedicated to market gardening. As you drive through this area, it is difficult to imagine when looking at the nearly tended fields and rows of vegetables that it is only just over 100 years since widescale settlement began. Then, apart from some fern-covered land cleared by the Maori, this entire region was covered by forest, with kauri dominating the higher reaches and kahikatea the lower, more swampy area.

Continue south and you will reach the Waikato proper. Here, and at the Waikato River itself, is a series of lakes and some of the most important wetlands of the North Island. The Waikato is our longest river at 354 kilometres and was of major importance to the Maori as it allowed easy passage by canoe to many parts of the country. Originally the Waikato entered the Pacific Ocean via the Hauraki Gulf, but millions of years ago it changed direction - apparently as a result of an earthquake - and began to flow into the Manukau Harbour. Finally it broke through the coastal hills further south and now flows into the Tasman Sea near Port Waikato.

The various eruptions of Taupo to the south dumped massive amounts of pumice into the Waikato River, blocking it and causing it to overflow its banks and change course. From a point at Piarere, between Tirau and Cambridge, the river has sometimes flowed north down the Hinuera Valley past Matamata, and at other times travelled through the Karapiro Gorge and then past Cambridge.

After leaving the Karapiro Gorge the Waikato dumped huge amounts of sediment in a fan across the floor of what is now called the Hamilton Basin. Over time the river has taken different courses across the fan and in its wake it has left sand and gravel levees, or natural stopbanks. These have blocked the drainage of the plains, forming lakes and wetlands.

Chief among these wetlands is the Whangamarino Swamp, now separated from the river itself. Some 7000 hectares in area, it is exceeded in size in the top half of the North Island only by the Kopuatai peat dome on the Hauraki Plains. To reach Whangamarino take the turnoff on State 1-lighway 1 to Te Kauwhata. This is clearly signposted some 76 kilometres south of Auckland. At the first hill a good view can be had of Lake Waikare on the right and Whangamarino straight ahead and off to the left.

Just after passing through Te Kauwhata a no-exit road called Swan Road leads off to the left, ending at the Raeo arm of the swamp. This area is popular with fernbirds as well as with bittern and although the cryptic colouration of these birds makes them hard to spot, their foghorn-like booms can be clearly heard on summer evenings.

Back from Swan Road take the road to Waerenga which will bring you to the second major southern extension of the swamp. About four kilometres on, this road crosses the Lake Waikare Outlet Canal and the third road to the left past this is Falls Road, leading to Island Block and Kopuku. A bridge across the Whangamarino River is six kilometres further down this road, and the swamp beside the bridge is prime waterfowl habitat.

The Whangamarino Swamp has earned publicity in the past because of large parts having been burned off in feuds between marijuana growers. In the inferno, chicks of rare species such as the bittern perished along with species such as fernbirds which are weak flyers. Survivors have been forced to move into parts of the swamp occupied by other birds, so the chances of their breeding are slim. Department of Conservation officials estimate that approximately one-third of the 9000 fembirds in the swamp died in the fire and although 6000 birds of one species might seem a healthy remnant it must be remembered that these birds now only survive in small areas of swamp and are highly vulnerable. And even birds such as the spotless crake, which probably escaped the fire, now have a greatly reduced habitat.

It was not only birds that suffered. Some of our rarest rushes and ferns grow at Whangamarino and botanists fear that it will take 25 years for the damaged habitats to fully recover.

However, there are substantial parts of the swamp that escaped unscathed and these provide shelter and feeding grounds for large flocks of waterbirds. Mallard and grey duck are the most common with a population estimated at around 50,000 birds. There are also some 3000 black swans found here, along with lesser numbers of grey teals' shovelers black shags and pied stilts.

These birds are in reasonable numbers in other wetlands, as well as in the lakes along the Waikato River. Not far from the Whangamarino Swamp are the lakes of Rotokawau, Kopuera, Whangape, Waahi, Ohinewai, Rotongaro and Hakanoa, all fringing the present or former courses of the Waikato and the combined waterfowl population of this area is probably more than a million birds.

The Waikato River itself might seem to be a prime habitat, but introduced alder and three types of willows which have taken over many of the swamps now dominate all the river banks making them unsuitable for the breeding of many species. Shags, however, find the willows ideal for nesting and roosting.

South of the wetlands one finds the farmlands that typify the Waikato. The 'Europeanisation’ of the Waikato landscape means that one can drive through much of it without seeing a native bird and very seldom a native tree. However, the introduced trees now growing here are often much larger than the same types in their countries of origin. Avenues of poplars and planes and groves of oaks give parts of the Waikato a park-like appearance.

Just over 50 kilometres past the Te Kauwhata turn-off on State Highway 1 is Hamilton, administrative and commercial centre of the Waikato. Hamilton has its fair share of colourful trees, including a flowering gum in Princes Street, and some particularly fine trees line the beautiful riverside paths. A trip up the river on a tourist boat will help visitors appreciate the beauty of what some consider to be a rather forgettable city.

Moving south of Hamilton along State Highway 1 and through some of our most fertile farmlands brings you to Cambridge. This area was once mostly covered in forest but after the land was confiscated from the Maori during the New Zealand Wars widescale clearance began and today only small pockets of forest remain around Mt Pirongia and Maungatautari Mountain or the remoter areas south of Port Waikato.