According to the Department of Agriculture, Water and the Environment of Australia, feral cats threaten the survival of over 100 native species in their country. They have caused the extinction of some ground-dwelling birds and small to medium-sized mammals. Feral cats are those that operate in the wild and can survive without human reliance or contact. They are the same species as domestic cats.
Australia’s federal parliament released a report that confirmed that cats were the primary drivers of mammal extinctions in the country. The report says that every year, each individual feral cat in Australia kills 390 mammals, 225 reptiles and 130 birds. In total, feral cats kill 1.4 billion native Australian animals yearly.
Cats arrived in Australia with the first European settlers in 1788. Within 70 years, cats had spread throughout the country. Cats now inhabit 99.9 percent of Australia’s total land area.
Rabbits on the other hand, arrived in Melbourne, Australia on Christmas Day in 1859. English settler Thomas Austin had requested the animals, hoping to establish a rabbit population on his new Australian estate. From just 24 rabbits, there were thousands of them after three years. By 1865, Austin reported he had killed 20,000 of the animals at his estate.
Invasive rabbits have made a serious impact on the ecosystem in Australia. According to the National Geographic, their numbers became so large that they destroyed crops and land, leading to soil erosion. They also negatively affected agriculture and plants by overgrazing. Not only did the rabbits wreak havoc on Australian croplands, they contributed to the decline of native plant and animal species.
There are currently an estimated 200 million rabbits in Australia, according to Rabbit-Free Australia, a group that works to educate people about feral rabbits and eradicate them. They multiply quickly. They can reproduce at a young age, and can reproduce all year round.
Cats and rabbits in Australia thrive because they have no natural predator (an animal that eats them). The predator-prey relationship promotes stability in ecosystems. With no animals hunting them down, their number multiplied uncontrollably.
Australia’s cats and rabbits invasion highlights the importance of preventing the entry of non-native animals, and even plants, to our country. This is the reason for the strict quarantine protocols in ports of entry. Sadly, some people don’t understand this. They bring exotic pets and seeds with them from foreign lands. As a result, we now have invasive species in the Philippines like the janitor fish and Chinese soft shell turtle.