Kowhai corridor

I’ve often thought that food corridors or food islands are a great idea to benefit our native birds and here’s a long-term joint project that is doing just that. West Otago Lions and Blue Mountain Nurseries, which is celebrating 90 years in business, in early September planted 55 kowhai trees, adding to the 200 planted in 2015, as part of their project to create a nature corridor at the base of the Blue Mountains in Tapanui.

The trees are a late winter-early spring food source for nectar-eating birds including bellbirds, waxeyes, tui and kereru (wood pigeons). The kowhai (Sophora) have been sourced from all over New Zealand, as well as Chile and Lord Howe Island, so the nature corridor also serves as a genetic library. The various species planted have been catalogued by Denis Hughes, patriarch and plant breeder at Blue Mountain Nurseries, and their locations recorded so plants can be reproduced or selected for future plantings in the district or nationally. Denis is a real expert on this New Zealand native tree and you can read his descriptions of the types that the nursery stocks here.

Sophora godleyi growing beside the Rangitikei River at the historic Springvale Bridge. Photo: Sandra Simpson

Denis’ list includes something called Rangitikei kowhai, which caught my eye, given my connections with that area. A quick Google later had me reading a 2016 Rangitikei District Council newsletter with a section written by the parks and reserves team leader.

This kowhai is one of the last to flower … The hills around Taihape are covered in this plant and it is a real treat to see them in full bloom. Sophora godleyi, also known as Godley’s kowhai, papa kowhai, or Rangitikei kowhai. Grows naturally in the west of the North Island from Te Kuiti to Manawatu … Is named after Dr Eric Godley [1919-2010], former head of the Department and Industrial Research (DSIR) Botany Division. It differs from other kowhai, in that it has a more twisted juvenile appearance which grows out with time. It is an extremely hardy plant that thrives in most areas of our region.

S. godleyi is particularly abundant in the catchments of major south-draining rivers, such as the Pohangina, Rangitikei, Turakina, Whanganui and Mangawhero. Its distribution may have been influenced by the Taupo volcanic eruption some 1,850 years ago, for it isn’t seen on the Central Plateau to the north.

It grows mainly on unstable bluffs, rock outcrops and hillsides so doesn’t have much to compete with and, unusually for a New Zealand native tree, doesn’t have a different juvenile phase which allows for a first flowering just a few years after establishment.

Rangitikei kowhai in flower above a stream in the Taihape area. Photo: Sandra Simpson

In his small book, Bulls: A History of the Township, farmer and naturalist Major R A Wilson (1909-1964) recalled that near the Bulls Bridge over the Rangitikei River was once an extensive flat covered with kowhai trees. In spring, he wrote, these trees were a mass of golden bloom that attracted hundreds of tui.

One year I met a … man and his wife admiring the beautiful sight and on talking to them found that though they lived in a district many miles away they made a special pilgrimage to Bulls each year to see it. There was generally a flood in the river about that time [September] which was known as the kowhai flood. I was a boy at the time and thought it strange to come merely to see the kowhai in bloom but in a later age I feel it was well worth the journey. Alas! Now the whole flat is gone [after flooding] and the kowhai with it.