Colonizers first brought cats to the island in the 18thcentury. Their numbers have grown so large--estimates range from 2-6 million--that they are decimating native wildlife. Per day, cats are estimated to feed on millions of birds, reptiles, and small mammals throughout the continent.
Feral cats are attributed to approx. 750 native animals deaths per year. Additionally, domesticated cats (pets) also contribute to the death toll with approx. 75 native animals each year. This combined total accumulates; up to 2 billion small animals native to Australia are killed by cats each year.
Strategies authorites use in an attempt to control the population of feral cats include shooting, trapping, and poisonous sausages. The hope is to cull up to 2 million cats by 2020.
Airplanes drop the sausages, which contain one of two poisons, over large areas of land populated by the feral cats.
One poison uses a substance derived from a native Australian plant, poisonus to the invasive cats but innocous to the native animals because evolution has equipped them with the necessary resistance.
Another lethal compound, called Curiosity, comes in hard pellets. Studies have shown that native species avoid the hard pellets but they are swallowed whole by cats.
These measures may seem extreme but this is just anohter example of the damage that can be done by invasive species when left unchecked.
