Pest exclusion fencing is designed to prevent various types of vertebrate pest animals from contributing to the loss and decline of native species, particularly plant species, in a given region. A 'vertebrate' animal is an animal with a backbone, such as mammals, birds, reptiles, amphibians and fish. In Australia, some of the most common vertebrate pests include:

• Feral rabbits
• Feral pigs
• Feral goats
• Feral cats
• European red foxes

Every year, federal and state governments contribute significant funding towards controlling the spread of these pests and protect areas of high conservation value. Aside from pest exclusion fencing, some of the other control strategies used include

• Poison baiting
• Burrow fumigation
• Release of biological agents
• Shooting
• Trapping

However, pest exclusion fencing, which is used to create "islands" of flora and fauna protection, is considered the most humane way of controlling vertebrate pests.

Some of the disadvantages of pest exclusion fencing include:

• They can be quite expensive to build
• They take a lot of time to monitor and maintain
• Infrequently, native animals have been injured or killed in pest exclusion fencing
• Not always 100 per cent effective; breaches may occur, particularly around gates and waterway crossings

When to use pest exclusion fencing?

When deciding whether or not pest exclusion fencing should be used to protect areas of high conservation value, authorities must establish whether it is necessary and capable of achieving desired outcomes. While breaches are to be expected, often these are considered infrequent enough not to compromise the efficacy of the fence. Sometimes, electric wires are used to make the fence more effective, while other control strategies, such as those listed earlier, are used in tandem with pest exclusion fencing to decrease the number of challenges to the fence in the first place.

Due to Australia's relatively flat terrain and sparse vegetation which is spread across much of the country, pest exclusion fencing has always been widely used here, and some of the most famous pest exclusion fences in the world have existed on Australian soil.

Some of the most famous pest exclusion fences in Australia and New Zealand include:

• The Rabbit-Proof Fence: Pest exclusion fencing was first used to stop the spread of the European rabbit away from Western Australian pastoral areas. Taking six years to build at a cost of (at the time) £337,841, it was completed in 1907 and stretched for 3,253 km. The fence has also been referenced heavily in popular culture, and the critically-acclaimed 2002 film Rabbit-Proof Fence featured it heavily.
• The Dingo Fence: Built during the 1880s, the Dingo Fence was designed to keep dingoes out of the fertile south-east of Australia, as well as protecting sheep in southern Queensland. At 5,614 km in length, it is the longest fence in the world, running from Jimbour in Queensland to the Nullarbor Plain in South Australia.
• The Maungatautari Restoration Project: A 47km pest exclusion fence enclosing 34 square kilometres of bushland in the Waikato region of New Zealand's North Island. Since it was completed in 2006, the area has seen the reintroduction of various native species, including the kiwi, takahe, toutouwai, kokako, tuatara, popokatea and hihi, thanks to the exclusion of pests.