A group committed to reducing the number of pests in Marsden Valley has had a productive year, though its hard work could be undone by a natural phenomenon that could see the pest population explode.
The Marsden Valley Volunteer Pest Trapping Group has a dedicated bunch of trappers who work in the hills surrounding the valley, laying traps to kill pests such as stoats, mice and rats.
Group member and Nelson city councillor Ian Barker, who does not head into the hills trapping himself, said experienced trappers and local residents such as Don Sullivan and Henk Heinekamp had put in place systems that had reduced the number of pests and allowed birdlife to flourish.
"Just in a year, the difference a person like me ... a layperson in ecology ... the birdlife I witness and hear when I go up there is incredible."
Since 2006, Mr Heinekamp has managed to tag a large variety of birds on his property in the valley, including bellbirds, tui, dunnocks, chaffinches and a yellowhammer.
However, this year beech trees in the area are expected to carry out a process called masting, whereby they drop a large amount of seeds.
This provides food for rats and stoats, whose populations can explode.
In turn, this makes it more likely that birds will be targeted by the pests.
Nelson City Council parks operations coordinator Lindsay Barber told members of the trapping group in the valley yesterday that there was a limited budget for trapping, and throwing around large amounts of money would probably not be effective. "It's the trapping strategy that is going to work long-term."
He said regularly getting around the traps would be the most effective strategy.
Rick Field, the project manager for the Brook Waimarama Sanctuary, said having a pest-free zone near the proposed sanctuary would take the pressure off its protective fence and create a buffer zone around it that would allow even more wildlife to thrive.
"The birds are going to fly over the fence," he said.
"They will breed inside and spread out."
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