Ngā Tohuwhenua Mai Te Rangi: A New Zealand Archeology in Aerial Photographs
Umu and umu tī
Umu and umu tī
Ovens exposed by wind erosion and ploughing on the river terraces at Waitaki River mouth
This area is one of the most important moa-hujitihg sites in New Zealand, dating from the thirteenth century. Carcasses were probably rafted down to a long-lived settlement here. The main river ran past the site immediately to the north, giving access to the site from the sea over a bar, but has since worked its way further north. The ovens show clearly in this photograph taken in about 1960. A crop of wheat or oats had been taken from little-ploughed land, and this photograph was taken after the oven marks had been 'freshened' by discing the crop stubble. The individual circular patches are about 6 m across while the larger area is some 250 by 50 m. The view is to the north.
Ti was amongst the tree crops cultivated by the ancestral Polynesians. In New Zealand the native tī (cabbage trees) would have been readily recognised as a potential source of food. The tī roots were prepared for consumption by cooking or steaming in a high-temperature process which converted indigestible starches to fructose (a type of sugar), with a required cooking duration of some 20-40 hours. 15 The problem of maintaining high temperatures over such a long period was solved by building very large ovens, as much as 8 m across and a metre or more deep, known as umi tī. They are widely recorded in the South Island south o Timaru, and an Otago Peninsula example is shown here. 16 The need for a starchy or sugary food derived from tī would have been greater in the south, in areas when kūmara could not be grown.