Valley pests in the firing line
A pest control operation targeting goats, pigs and deer will start next month on a 7000-hectare area in the Maitai River and Roding River catchments.
Nelson City Council group manager environmental management Clare Barton said the goal was to restore forest health in the Maitai and Roding water reserves.
The reserves included the largest intact forest ecosystems in the Nelson region, and had threatened plants associated with the limestone geology in the area, she said.
‘‘Browsing deer and goats remove a range of species from the understorey, making it less diverse and preventing young plants coming through to take the place of old.’’
The vegetation supported species like a local giant land snail, she said.
Due to seasonal fluctuations and open boundaries, it was difficult to pinpoint exactly how large the population of the various ungulates in the area was, Barton said.
‘‘Regular hunting efforts from the caretakers and permitted recreational hunters do a good job when numbers are high. This control operation aims to reduce numbers to very low level levels in the long term, so the forest has a chance to recover.’’
The first part of the operation will begin in mid-September and run for two weeks. Initially, it will target 4700ha, expanding to cover 7200ha in the next two years.
The council has hired wildlife management company Track and Trigger to complete the operation. Director Jordan Munn said a combination of traditional methods and thermal imaging would be used.
Munn left school at 16 to become a possum hunter. Nine years later, he has worked around New Zealand and overseas and is the owner of $100,000 worth of pest control technology and one of just two such operations in the country.
Using military-grade thermal imagining equipment had revolutionised pest control and eradication, he said.
‘‘Once, we would spend two to three weeks at a time on an island, and you’d be limited by vegetation, topography and weather. I thought there had to be an easier way to do it.’’
He uses thermal imaging to ‘‘track things the human eye can’t see’’, while a laser, which ‘‘makes a green dot on the hillside’’, helps to pinpoint a target animal’s precise location.
Barton said there would be restrictions on access to public walking tracks during the operation. The council will post signs at track entrances and notices on its website before the operation starts on September 17.
‘‘Browsing deer and goats remove a range of species from the understorey.’’
Clare Barton, Nelson City Council