Contract Wild Animal Control New Zealand operations planner Guil Figgins, speaking at a Beef + Lamb biosecurity workshop in Becks last week, said his work included possum control for Ospri in Mount Allan in Dunedin.
In a bid to find tuberculosis, about 240 pigs were shot over two days in East Otago earlier this month.
"We could have kept going — pigs are a big problem at the moment."
The heads of the pigs were collected to be sent to a lab to detect the disease.
Wild deer numbers were on the increase.
About three years ago, farmers would ask them to leave wild deer alone when they were shooting wild pigs from helicopters on their property.
"Now they are saying please shoot all the deer."
He urged farmers to use a simple formula to create a biosecurity plan.
The first step was to identify the risks, such as possums, pigs or weeds.
"You’ll have a mixture of plant and animal species."
Monitoring was the second step to identify the scale of a problem and discover the pests present by using methods including trapping, wax tags and identifying animal droppings.
"Mapping is important to find out where you want to spend your resources because you might have a big property and you don’t need to do pest control over all of it, you just need to target the habitat where that pest is."
A job for the Otago Regional Council last year had a team of 15 people walking an area between the Kakanui Range to Danseys Pass to look for wallaby droppings.
"They were all trained to recognise wallaby poo."
The team walked about 30,000km in a year.
Any droppings collected were DNA tested.
If the test revealed it was from a wallaby, a shooter with thermal binoculars was deployed in a helicopter to try to get it.
The price of thermal binoculars had fallen and were an "invaluable tool" for farmers wanting to detect pests.
"They are amazing."
The second step was to work out what was needed for the third step of implementing a pest control plan including a timeframe.
Pest control methods included traps, which needed to be checked daily.
In some areas, he had set 20 traps and regularly caught 18 each day for days on end, he said.
Another method was the use of toxins, some of which required the user to have a handling certificate and a consent from the Ministry of Health.
The process for obtaining the certificate and consent was straight-forward, he said.
"It’s not as hard as you think."
After the control work, monitoring needed to continue to show if it was working.
Private clients he had worked for included a group of about 100 landowners to control possums in a 30,000ha block in the Catlins.
"It’s economies of scale, if you all bunch together it just gets cheaper and cheaper.’
The possum population in the Catlins had "gone through the roof" since Ospri had stopped control work after tuber
shawn.mcavinue@alliedpress.co.nz