Lots of rats and few birds in the Tararua Ranges

Lots of rats and few birds in the Tararua Ranges

Surveys revealing high numbers of rats and few birds in the Tararua Forest Park have highlighted the need for pest control.

Rodent and bird surveys were undertaken in the park over summer by Department of Conservation and Greater Wellington Regional Council staff and volunteers, to establish baseline data for the Project Kaka – Tararua nature recovery programme, which begins in spring this year. The programme aims to restore biodiversity values, including birds, insects and plants, through simultaneously controlling rats, stoats and possums on a three year cycle over 22,000 ha of the Tararua Forest Park.

Dr James Griffiths, a monitoring ecologist with DOC, said the survey results were of concern to the department.

“They suggest that previous pest management in the Tararua Forest Park has not been of sufficient intensity to protect vulnerable bird species such as kaka, kakariki and kereru, which are now present only in very low numbers.”

“Although it is difficult to determine the relative impact of rats on Tararua native birds from that of stoats and possums, high rat numbers are likely to be impacting on vulnerable bird species. Ship rats, stoats and possums are the main predators of New Zealand forest birds, and are all likely to have played a role in the demise of the Tararua birds.”

The good news is that, although rats were recorded in 48 percent of 400 tracking tunnels in the Tararua Forest Park, they were almost undetectable in 150 tunnels in the Hutt water collection area where aerial application of 1080 baits took place in August last year.

“We expect to see an increase in bird numbers in the Hutt water collection area next year as lower rat numbers mean that fewer chicks and eggs will have been eaten by these pests this year,” said Philippa Crisp, Greater Wellington Regional Council’s Parks team leader, strategy and environment.

DOC is hoping for similar results when it implements Project Kaka.

“Pest control every three years in the Project Kaka area between Otaki Forks and Mount Holdsworth should restore a thriving forest community to some of the most popular tramping tracks in Tararua Forest Park,” Dr Griffith said.

“We hope that people visiting the project area will one day be able to see flocks of kaka and kakariki, and mistletoes and rata flowering on the hillsides.”

ENDS

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