Introduction

This integrated species protection programme operates in the beech forests that line the Maruia Valley.

You see these forests west of the main divide on the highway between the East and West Coasts over the Lewis Pass. 

The Maruia Valley has played an important part in New Zealand’s conservation history, being the inspiration for the Maruia Declaration. The Declaration, circulated as a petition and radical at the time, demanded legal recognition of native forests and an end to their logging. In 1977, the Declaration was submitted to the government, and almost all of its demands were met over the following 30 years.

Long tailed bat. Image: Ian Davidson-Watts.
Long tailed bat

About the programme

The protection programme is designed to protect and enhance the biodiversity values at key sites within the Maruia Valley through pest control. This area has a high diversity of both common and threatened beech forest species with relatively intact beech forest ecosystems.

Beech trees are not especially vulnerable to damage from pests, but other plant and animal species that live in beech forests are. Plants such as mistletoe have disappeared from many forests where there is no pest control.

An intensive species protection programme is currently being implemented within a core area of the upper Maruia Valley. This is to protect existing populations of South Island kaka and long tailed bats along with a host of other indigenous forest bird species.

1080 pest control operations are undertaken in beech mast years, to control the huge increase in rats, and subsequent rise in stoat numbers that occur during these masts. A 30 km trap line using DOC 200 traps has been installed to control stoats and rats in between operations.

The possum control plan within the Maruia Valley currently involves a large scale aerial 1080 operation for control of rats and possums and is triggered by rat plagues due to beech mast (seeding) and possum densities above 5%.

In addition, possum control by trapping is undertaken between 1080 operations to maintain possum numbers to low levels in the Station Creek, Lake Daniell and Alfred river areas. This trapping is undertaken to protect very vulnerable scarlet mistletoe, red mistletoe and yellow mistletoe from possum browse.

Effectiveness of the programme

Data from three monthly rodent monitoring shows that since an aerial 1080 operation in 2009 the rat densities inside the treatment area were suppressed to low densities for more than a year after the operation while in the non-treatment area rat densities have never dropped below 20% and remain elevated.

Due to a partial silver beech mast event occurring in the summer of 2011 rodent densities inside the treatment area have started to rise.

Other species protection work

As well as possum, rat and stoat control, other work including goat control and invasive weed control is being carried out regularly.

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