Tree Nests Trial Hits Jackpot

27 May 2014

An experiment to turn old, unwanted trees into nesting sites for native birds has hit the jackpot.

Arborist viewing a silvereye nest in a dead tree.

Arborist with the silvereye nest


A silvereye nest has been found in a nesting cavity cut into an old sycamore tree in the hills above Brooklyn. In May last year, holes were cut into three trees – and to find a nest in one of them is a win for the Council’s Tree Team manager, David Spencer.

It was David’s idea to get arborists to cut holes and slits in old, dead and dying pest trees, rather than remove those trees and destroy habitat for native birds, lizards, insects and fungi.

Working with Council Biosecurity Technical Advisor Illona Keenan the idea is to protect and restore biodiversity. The nesting cavities encourage birds like the silvereye and the more at-risk kaka, kakariki and saddleback to breed. “These are cavity-nesters and they require that habitat and environment,” Illona says.

Polhill Reserve and George Denton Park were chosen for the trial because of a problem with sycamore trees, which threaten the native tree canopy.

The holes cut in these pest trees will eventually kill the trees but not before they play host to a range of native species.

“In the past we would go and cut down the trees if they had splits and fungi. We had all these nice tidy big trees, but no habitat. Standing deadwood is a very vital habitat,” David says.

For safety reasons no dead tree is left standing near tracks, houses or places where people commonly go.

David says the technique is used in Europe and the United Kingdom, but he believes this is the first time it has been tried in New Zealand.