The annual TBFree pig survey in the Catlins has just been completed.
The survey, which takes place in an 167,000ha area between Clinton and Chasland, is completed by Contract Wild Animal Control New Zealand Ltd (CWACNZ).
The group has a three-year contract to complete the surveys.
CWACNZ supervisor Lyndon Dynes said the survey involved a team in a helicopter and teams on foot shooting pigs and gathering the heads.
“We are not there to shoot every pig but we want a representative sample of the whole area,” Mr Dynes said.
The glands on the pig’s jaw were analysed to find out whether bovine Tb was present.
“If there is something .. those landowners will be notified by TBFree.”
A GPS reading was taken where each pig was shot and a tag put in the pig’s ear, so if it gave a positive Tb result action could be taken in the area where the pig came from.
Pigs were ideal animals to survey.
“They scavenge, a bit like a vacuum cleaner.
“If they’ve eaten a ferret or a possum with Tb then the pig will pick it up and generally encase in their glands.
“They are not classed as a carrier or spreader.”
Pigs could become carriers if a hunter gutted a Tb-carrying pig and left the remains on the ground.
“Either pigs or ferrets or possums will then scavenge on that, and that can keep the cycle going,” Mr Dynes said.
One hundred and forty pigs were gathered during the three-week survey.
It was hard to estimate the area’s pig population but there was a low to medium density of the animals, depending on the habitat.
“The pig population is patchy over the whole area.”
About half of the 167,000ha in the area was pig habitat, much of it farmland.
“We do appreciate the support of the landowners.”
The first survey was carried out last year and no Tb was found in the samples.
“We’ve got one more year and I would imagine if this year and next year come out clear then the work will stop, which is good.
“Basically TBFree have proven either the presence or absence of Tb.”
Mr Dynes had been involved in the eradication of Tb in Southland and Otago for about 30 years.