by Adam Jablonski
This tempering of language only disguises the fact that Australia is still on the wrong path when it comes to managing feral cats. Pursuing this "eradication-lite" strategy ignores the lessons still being learned on Marion Island, where the elimination of cats (which took "only" 19 years to achieve) has led to an explosion in the population of mice, which just so happen to prey on some of the same sea birds the South African government sought to protect from feral cats. With the cats gone, the mice are now literally ruling the roost.
A recent study on Tasmania, the island state off the Southern coast of Australia, should also have given mainland officials pause, as it showed regular trapping and shooting of feral cats over a thirteen-month period actually led to an increase in the overall colony populations between 75 and 211 percent. The study's author told Australian media recently, "In the areas that I had tried to reduce cat numbers, I recorded an increase in cat numbers. I actually had more cats running around on those sites than beforehand."
In line with this study, the new Draft Threat Abatement Plan describes shooting as a not particularly effective nor efficient method of cat management; it is very labor intensive to send shooters out into the wild, and they must be highly skilled in order to hit their targets. So instead the plan is focusing on another lethal control method, creating and deploying poison baits that are hand-placed or dropped from airplanes or helicopters. The two poisons touted are Eradicat, which contains the well-known 1080 poison that has been used to kill foxes in Australia since the 1990s, and a newer, "improved" version called Curiosity.
Curiosity's toxin works by blocking an animal's blood cells from releasing enough oxygen into the body. The government of New Zealand says it, "creates a lethal deficit of oxygen in cardiac muscle and the brain, Death in stoats and feral cats usually occurs within 2 hours after eating a lethal dose." It is considered more humane than 1080 poison because it kills faster. Yet Curiosity has not been particularly successful in studies. Every cat observed in a study from summer 2012 survived, and nearly half of the cats observed in a summer 2013 study survived. In both trials researchers concluded poisons were in the right place among the cats, but for some unknown reason were not consumed.
Both poisons are held up as relatively cheap ways to go after many cats over large areas, but therein lies a major problem. Other animals live in these targeted areas, including the threatened and endangered species the government seeks to protect. The risk of unintended poisoning is significant, both directly by animals eating baits and indirectly by consuming a dead, poisoned animal.
In fact, concerns about 1080 poison and others led former President Nixon to ban their use on federal lands here in 1972. This is because 1080 poison is toxic to anything that breathes, from mammals like cats (and humans), to vertebrates such as birds, and even insects. Limited use was allowed again beginning in 1982, primarily to protect commercial livestock from predators like coyotes.
Compound 1080 is frequently used in Australia and New Zealand (coincidentally the world's number one consumer of 1080) for the same purpose, protection of livestock from deadly "invasive" species. But this is an interesting twist, because sheep and cattle, which are produced in enormous numbers in both places, are not themselves native to either country. The real intent then becomes clear; poisoning of predators is not for the well-being of "native" animals, but for the fattening of ranchers' wallets.
Death by 1080 poison is inhumane, and the same should be said for Curiosity. The emphasis on lethal poisons exposes the hard truth that the Australian government is not really interested in broad-scale, non-lethal, humane management techniques at all. It has rated the relative humaneness of different killing techniques, shown in the accompanying graph. To the government, shooting is the MOST humane way to kill feral cats, yet its new plan shifts resources to poisoning, which it rates as LESS humane. Of course, the only data point on this graph that is actually humane is where the X and Y axes meet, where no animal is killed by any method.