Mulberry Grove Community Rat Project by Judy Gilbert

Environmental News Issue 17 Summer 2009

The Mulberry Grove Community Rat Project was launched in late February. About fifteen residents attended the launch meeting, opened by GBI Trust chair John Ogden, and hailed as the first urban community trapping project on island. Residents in the bay area which covers 96 properties will have commenced intensive trapping of rats in March. The goal is to reduce the impact of rats and in doing so give the native plant and bird species of the area a better opportunity to flourish.

This coastal area abundant with pohutukawa and flax attracts a variety of bird species, particularly tui and kaka. Rails are also seen frequently.

The project was initiated by the Great Barrier Island Trust, with Judy Gilbert from the Trust, and Des Casey from D.o.C taking the idea for a community rat project to local landowners in November 2008. Local residents were enthusiastic and appointed Cathy Scott to coordinate the project including the deployment of equipment onto each property, the stock of equipment required, and the results of the trapping.

As part of the project a trapping programme has already been established at Mulberry Grove School with a local person checking and baiting traps on a regular basis. The need for consistent trapping to get rat numbers down and keep them low was stressed at the meeting.

Sponsorship has been provided by the ARC for rat traps; the Windy Hill Rosalie Bay Catchment Trust for trap covers, string, and monitoring tunnels; and the coordination of landowners and provision of maps through Des Casey from D.o.C. Mulberry Grove School has also sponsored a meeting room and some printing costs. Bait for traps are to be supplied by the landowner.

Thank you to all sponsors.

A set of 10 rat tracking tunnels has been established through the bay area and a pre-management monitor done in December showed a 20% result and a second in February showed a 45% result. Tracking tunnels are a means of measuring rat activity in an area and the number of pre-inked pads (left overnight in a tunnel baited with peanut butter) that have rat prints marked on them can be worked to a percentage which indicates levels of rat activity. D.o.C in its Mainland Island conservation projects strives for a <5% tracking tunnel rate. In autumn a seasonal bulge of rats is generally observed with rats’ numbers peaking in March and April – so throughout this period traps need to be checked, reset, and baited freshly at least weekly.

At the meeting a data sheet was to supplied to each participant so that a record of the number of catches per month can be kept and a data base of trapping information developed. There is to be a prize for the most rats caught in March.

Of the 96 properties in the bay area there are around 25 residents and it is hoped that these people will, with the permission of the owners, manage a number of nonresident properties to ensure good trapping coverage of the entire area.

With the interest shown by the community it is planned to expand the project to include a fresh water stream and rail monitoring programme.

It is also hoped that other communities on island will be motivated to establish collectively organized trapping programmes. For more information contact Cathy Scott (082)