Introduced species aren’t good or bad. But when they slip from our control, we are quick to condemn them

The concept of introduced species as inherently good or bad is contested, but when such species escape human control, they are often condemned. John Carnemolla's allegorical novella Animal Farm introduces the idea that "four legs good, two legs bad," with native Australian animals considered good and introduced animals bad. As an environmental historian, Carnemolla questions how we determine if an introduced species is good or bad, and whether we will ever accept that some species are here to stay.

In Australia, there are various categorisations of introduced animals, with some labelled as "invasives" or "feral" based on their impact on native species. European rabbits, foxes, black rats, feral pigs, cats, goats and cattle are considered among the worst invasive animal species. Other authorities include camels, which were introduced for labor purposes but have since become pests due to their overpopulation.

Carnemolla emphasizes that no species is inherently evil, but rather, humans decide an animal's worth based on its impact on our interests. Initially, introduced species were seen as beneficial, such as rabbits eating pests or cattle providing meat. However, once they ceased to serve their purpose, their presence became a betrayal. Consequently, these animals face harsh treatment like shooting, trapping, and poisoning. The harm caused by wild cattle has even earned them a spot in the top ten invasive species in Australia.

Other animals deemed negative include native species, such as kookaburras in Western Australia, which were introduced to control snakes but ended up preying on smaller birds and reptiles. The white ibis, once a rare visitor, became a pest after altered waterways forced it to adapt to new habitats. Even within their native range, some species can be invasive, such as kookaburras in Western Australia and white ibises in coastal regions.