How pest control operations work

Ground control 

Our pest control contractors use toxins and traps to carry out ground control operations.

Contractors use different toxins — like cyanide — depending on the size and terrain of the area being treated. They consult with landowners on which toxins they’re using to ensure the safety of livestock, pets and native animals. Toxins are:

• placed in bait stations
• stapled to trees in biodegradable bags, or 
• hand-laid.

When using traps, there are many different types to choose from — like leg-hold or kill traps. To help choose the right kind for a particular area, we take a number of things into consideration, including:

• ease of access
• set-up and maintenance time
• the potential risks to livestock, pets and native animals.

Sometimes our contractors will use corflute chew cards or wax tags to identify where possum control is required.

Our TMA notices provide information on planned ground control operations around the country.

Aerial control

While possum control is mostly done using ground-based traps and hand-laid toxins, in some areas the most efficient method of control is aerial. During aerial operations, our contractors apply baits containing biodegradable 1080 from helicopters. Aerial control is efficient, cost-effective and extremely successful at reducing possum numbers to low levels. 

The Environmental Protection Authority publishes a post-operational report for each aerial control operation a year after completion.

Wildlife surveillance

Before an area can be classed as TB-free, we do surveys to find out if TB is still present in local wildlife. We do this by:

• trapping possums and other species, such as pigs and ferrets, that can catch TB
• doing post-mortems on them, and
• testing them for TB.

We do surveys in areas where we believe TB has been eradicated and don’t expect to find any TB-infected possums or other wildlife.

Pig surveys

In some areas, we use pig surveys to provide assurance that TB has been eradicated. Pigs are good indicators of TB in possums because they scavenge widely, so they’re likely to get TB from eating TB-infected possum carcasses. They can’t maintain TB within their own population, so if they're infected, it means it’s from another species.

To do a pig survey, our contractors collect wild pigs for disease surveillance using 1 of 3 methods:

• Hunting.
• Trapping. 
• Shooting from helicopters.

We send the pig carcasses for a post-mortem to check if TB is present.

Deer surveys

Wild deer do not readily spread TB to other wild deer. If we find an infected animal, we know it will have contracted TB from another species. In practice, deer are normally sampled in addition to other more TB-sensitive species, like pigs and possums. However, in some areas the only species available to survey is deer.  

We use specialist contractors to collect the survey data we need. Our contractors shoot the deer and take samples (or whole carcasses) for examination. We also collect data supplied to us by recreational hunters, if it includes data on the location of the kill.

In areas where our survey work could cause significant impact to recreational hunting, we consult with landowners and, where possible, adjust the survey to reduce the effect of our operations on hunting.

Ferret surveys

We run ferret survey operations in some areas across the country. While possums are the main source of infection for wildlife, it can be difficult and costly to detect TB in possum populations. Ferrets are good indicators of TB in possums because they scavenge widely, and are likely to get TB from eating TB-infected possum carcasses. Any findings of TB in ferrets will indicate that further possum control work needs to be done in an area.

Testing herds

Cattle and deer herds are monitored for TB through a combination of herd testing and carcass inspection at slaughter. How frequently we test depends on the herd’s location, management and TB history.

In areas that have been identified as Movement Control Areas (MCAs), farmers must get cattle and deer tested for TB before they can move to another herd or farm.