Best methods for feral pig eradication

By Susie Ross

As the feral pig becomes one of the most destructive animals throughout Queensland, the methods to control the intelligent pest are of great interest to many people. Feral pigs have adapted well with the ever-changing climates within Queensland and can now be found in most areas from coastal regions, north to Cape York Peninsula and out to central parts of Queensland.

Due to the difference in geographic types of land they cover, feral pigs can be especially difficult to control.  Agforce Pest Animal Coordinator Damien Ferguson said pigs would move where ever there was enough water and food to satisfy them. “In wet seasons they can breed second to rabbits, where as in dry seasons you will see a lot less pigs,” Mr Ferguson said. Feral pigs have a specific impact on agricultural farming land, national parks and coastal beaches. In each different environmental location, different methods must be used to efficiently control their numbers.

Pigs can cause significant damage to crops

Within farming and agricultural areas throughout Queensland, feral pigs have become an extreme menace to landholders. Mr Ferguson said grain farms had significant problems with pigs destroying many cereal crops. “Grain farmers can lose anywhere from $400 to $600 per a night in grain costs from each pig, which is why quite a few farms have gone out of business,” Mr Ferguson said.

The most prominent eradication method used by grain farmers is through baiting with 1080 poison. This is carried out most effectively when the pigs are pre-fed with grain on a regular basis to allow them to get used to being fed in a particular spot. The grain is then poisoned and has a significant success rate in killing the pigs. Mr Ferguson said the importance of feeding the pigs something which they were used to eating was crucial. “We had some farmers in the Darling Downs that got access to a tonne of bananas, but the pigs wouldn’t eat them,” Mr Ferguson said. This method of eradication has helped significantly for grain farmers.

Macadamia farmers also deal with feral pigs eating their produce. Australian Macadamia’s estimated the loss at $500,000 in their 2012 season within south-east Queensland. Eradication methods for these farmers have included fencing around crops which has been found to have a 100% success rate, however means that pigs will still move on to somewhere else. ‘Hog hoppers’ are a new apparatus which has been trialled by many farmers, which traps pigs but is still safe for native animals. Queensland Department of National Parks and Wildlife Ranger Daryn Storch said traps allowed the pigs to lift up a bar to access the poison and would stop other animals from eating the bait. “These traps work very well however they can be very labour intensive and can only be used at a limited number of sites,” Mr Storch said.

Sheep farms have also endured problems with eradicating feral pigs. Hansard reported that increasing pig populations had devastating effects on lambing rates as pigs would attack them straight after they were born. Mr Ferguson said adult pigs were able to eat up to five or more lambs per a day in some scenarios. “In places west of Stanthorpe or north, pigs will just walk up to them,” Mr Ferguson said. “The mothers can’t stop them as they will be hooked by their tusks as well.” The The Chronicle reported that sheep farmers were some of the hardest hit, with lambing rates being as low as 20 per cent. In these areas, aerial shooting as well as baiting has been used as a means of controlling the populations. Baiting with 1080 poison is effective if used in meat to lure pigs in. Mr Ferguson said aerial shooting was also used as a way of eradicating large numbers of pigs at one time. “Helicopter shoots can cost from $700 to $800 an hour, but if the pigs are in large proportions, the benefits far out way the costs,” Mr Ferguson said.

Cattle properties also face problems with reducing the number of pigs on their land. Although pigs are less likely to attack cattle, they face the problem of them eating a lot of feed as well as causing problems in creeks and water troughs. Cattle property worker Stuart Speed said the best method they used to kill pigs was by aerial shooting and also baits. “If the country is thickly timbered, a helicopter won’t be able to see the pigs, so then baits work best,” Mr Speed said. “Though there is no point in doing any of this unless everyone on our neighbouring properties is working together to get rid of the pigs,” Mr Speed said. The use of dogs to hunt feral pigs is also used on many properties. Mr Ferguson said it could be particularly useful if there was one loan boar which couldn’t be caught using other methods. “You can walk past some pigs and they will lie dead still, so a dog can be really useful to sniff out pigs that are hiding,” Mr Ferguson said. Mr Speed said although hunting pigs with dogs could have good results, it was very dangerous for the dog involved. “There are many risks to the dog, they can get hooked by a tusk which can rip open a dog and cause death,” Mr Speed said.

Feral pigs are also detrimental to water ways on many properties. Mr Storch said pigs could penetrate the bottom of a water hole through constant digging which would create a “hole in a bath tub” effect.  “We have lots of problems with pigs bogging up dams and causing erosion in river banks as well, sometimes it can even be that bad that cattle will avoid these areas,” Mr Storch said.

In many national parks throughout Queensland, eradication programs have been developed to control feral pigs. Hansard reported pigs were disastrous for national parks and consumed many native plants and animals, including frogs, lizards, snakes, turtles and nesting ground birds. Queensland national parks use a variety of methods to control feral pig numbers. These include aerial shooting as well as baiting and sometimes trapping.

Mr Storch said controlling pig populations could be hard as some areas were very hard to access, especially during wet seasons. “Lakefield National Park is one of the largest in Queensland and we have to try to eradicate pigs later in the year when they are searching for food,” Mr Storch said. “This is when we will try and eradicate the pigs through using aerial bating and shooting combined with ground traps and manually baiting on the ground.” It is important that the eradication programs are not only participated in by the national parks, but also surrounding neighbours. Mr Storch said that it was crucial that farmers worked together to combat the pest. “There’s no point in us trying to eradicate all of the pigs if they just keep on coming back because no one else is doing the same thing – everyone needs to work together,” Mr Storch said.

Although aerial shooting and baiting can be costly, it is used by the national parks to eradicate large populations of pigs at a time. Mr Storch said it was very effective especially if there was a specific area they were targeting. “If you are trying to save a wetland, it gives you a really quick response so you can do aerial bating then follow up with aerial shooting,” Mr Storch said. The Brisbane Times reported drones may be used to drop off baits to pigs in different areas. One drone would be able to carry up to seven kilograms of meat, enough to feed thirty to forty pigs. The national parks have to consistently focus on feral pig eradication. “As soon as you take your foot off the pedal with something like this, the population just starts coming back,” Mr Storch said.

Feral pigs cause detrimental effects to coastal regions around Queensland. They specifically target turtle nests where they eat the eggs as an easy source of protein. Mr Storch said pigs had learnt to sniff out the nests and eat large quantities of eggs which had a high impact on turtle survival rates. “At quite a few beaches we are getting very few turtles actually surviving and making it to the water,” Mr Storch said.

Under a new initiative beginning in June 2014, both the state and federal governments will give $3.5 million each, to go towards a four year plan to eradicate pests from harming turtles. The Courier Mail reported in some areas along the coast, up to 90 per cent of turtle populations had been destroyed by feral pigs. The Nest to Ocean Program will focus on turtles from above Bundaberg right up to the Cape York Peninsula, where many endangered turtles including the Olive Ridley turtle and the Flat-Back turtle are threatened by pigs. Mr Storch said hopefully by helping the turtles, they would make it to the ocean and each could live from 70 to 140 years while still coming back to the same spot to lay eggs.

“We use predator exclusion devices over the top of the nests and they work extremely well, however we have to find each nest so it is very labour intensive, but we have a lot of volunteers,” Mr Storch said. The nest protection will also follow with intensive baiting and shooting to target the pigs in each way possible. “We are just trying to keep the pig population down, to give the turtle population the best chance to rebuild,” Mr Storch said.

Eradication programs throughout Queensland are undertaken constantly to combat the number of pigs. With varying success rates through different methods, they need to be altered to depend on the landscape targeted as well as to the pigs in the areas.

*Picture by Susie Ross

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