Kawau Island, whose name stems from the many shag colonies there, lies just off shore in Hauraki Gulf, due east of Warkworth and 30 miles north of Auckland City. Approximately 5 miles long and 3 miles wide, the island is almost split in two by Bon Accord Harbour, which opens towards the mainland, so forming a fine natural anchorage. Much of the area of nearly 5,000 acres is clothed in native bush to which many exotic plants have been added. The highest point is Grey Heights (596 ft). The island is made up mainly of steep south-west dipping indurated greywacke and argillite of the Waipapa Group within which are pillow lavas, cherts, jaspilites and, near South Cove, associated copper and manganese ores. The overlying Waitemata Group sandstone and mudstone crops out along the north-east and south coasts and west from Ladys Bay. Contorted bedding is common in these rocks and fossils are found at Brownrigg Point and Fossil Point. Greensands at Fossil Point also show calcareous “cannon-ball” concretions of varying size and roundness.
The Maoris have left relics of their prior occupation of the island in the form of numerous earthworks, ovens, and middens which have yielded human bones. The history of early European ownership of the island is bound up with the involved processes of land transactions of that period. It is worth noting that the island was originally purchased from the Maoris by J. Taylor in 1837.
Conflicting dates have been given for the first discovery of manganese on the island, the accidental discovery of copper during mining of the manganese, and the opening of a rival mine. The original purchase of land and mineral rights extended down only to high-water mark and the authorities subsequently granted a separate lease of the mineral rights off Kawau below high-water mark. This led to the establishing of a second mine between high- and low-water marks and to bitter litigation between the mine owners. This was halted only when the senior company bought out the other and amalgamated the two mines. The period for which the mines worked, their total output, and the reasons for their closing are not clear, but it is known that £60,000 worth of copper was extracted in a four-year period and that the workings were certainly closed by 1869. The probable output of about 3,000 tons almost certainly exhausted all the richer ore, and the low value of the remaining ore may well have been the more pressing of a number of reasons for abandoning the workings. The workings were dewatered in 1909, but no ore was extracted, and drilling in 1953–55 failed to find a workable extension of the lode.
In 1862 Sir George Grey purchased Kawau, and the mine manager's house was converted into the imposing Mansion House at considerable expense. To the generally drab native bush, brightened only by the colourful rata, pohutukawa, clematis, kowhai, and manuka, were added exotic trees and shrubs from temperate and subtropical regions around the world. Fruits were acclimatised and it was during this period that the first prolific New Zealand grapefruit, known as poorman orange, was isolated. Regardless of expense, animals and birds were imported to grace Grey's “earthly paradise”. In this setting Sir George entertained lavishly – both commoners and celebrities, Pakeha and Maori, receiving his hospitality. In 1868 Prince Albert enjoyed shooting on the island, although at that time Grey had retired from public life.
In 1888 Grey sold the island on which he had spent most of his fortune. The island then passed through a number of hands until in 1910 the inevitable subdivision began. By then the Mansion House had already become a guest house for visiting yachtsmen. With improved roads to Sandspit on the mainland, the island now attracts touring motorists as well. The section, covering some 86 acres around the Mansion House, has been repurchased and some exotic trees planted. For today many of Grey's imported trees and shrubs have gone, as well as birds and animals. Whereas the zebras never became acclimatised to their new home, the monkeys did so well that they had to be exterminated as pests. The deer, opossums, and, above all, the wallabies also flourished, but attempts to eliminate them have proved futile and, with the kookaburras and royal palms, they remain as the more notable legacies of Sir George Grey's earthly paradise. Kawau may never again attain the glory of its past days, but the lovely walks through bush to vantage points, such as that on Grey Heights, to small secluded beaches or to rocky coasts, are no less attractive now that the exotic has merged into the native.
by Frederick Ernest Bowen, B.SC.(DURHAM), New Zealand Geological Survey, Otahuhu.
- N.Z. Journal of Geology and Geophysics, Vol. 4 (1961), “The Geology of the Cape Rodney – Kawau District, Auckland”, Hopgood, A. M.
- Sir George Grey, 1812–1898, Rutherford, J. (1961)
- Kawau Island, Sheffield, C. M. (1962)
- Fourth Triennial Mining Conference, Otago School of Mines (1959), “The Sulphide Lode on Kawau Island”, Williams, G. J.