Fatal second-generation rat poison kills Qulls and Tasmanian Devils to endanger the threat of extinction

Humans have been poisoning rodents for centuries. However, rapidly breeding rats and mice have evolved resistance to previous venom. In response, the manufacturer is producing second-generation anticoagulant rodents, such as bromagiolon, which is widely used in Australian households.

Unfortunately, these powerful poisons do not magically disappear after the rodents die. For example, it is well-known owls who eat poisonous rodents that suffer slow death from internal bleeding.

A new study published in the Journal Science of the Total Environment shows that this problem is much larger than that of an owl. It turns out that the four Cool species, Australia’s five largest marsupial predators, and the Tasmanian demons, are also collided with these poisons.

Half of the 52 animals we tested had these venoms in their bodies. Some of them were dead after that. These species are already threatened by foxes and wild cats. Rat poison is yet another threat, and they may not survive. Other countries have moved to ban these poisons. However, it is widely available in Australia.

How do mouse poison fall into the Tasmanian demon?

The Quolls and Tasmanian Devils are carnivorous animals. They eat mammals, birds, amphibians, and reptiles and find food by hunting. But do they eat enough poisonous rats and mice to be at risk?

To investigate, we analyzed liver samples from all four Australian cool species and the iconic Tasmanian demons. Samples came from dead animals from various sources that were found dead in veterinary care, roadkills, or found simply dead.

Each of these is endangered or vulnerable. Together, they represent the largest remaining Australian carnivorous marsupials, the native animals at the top of the food chain.

Samples were tested from 52 animals. Half of these were positive for second-generation anticoagulant rodents. Of these, 21% were tested positive in multiple rodents.

Unfortunately, many of the animals we tested consumed enough height to kill. Approximately 15% of the Tasmanian demons, 20% of the Eastern Cools, 22% of Chudic (Western Cools), and 20% of the spotted tailed Cools that were tested die from either the poison itself or the associated cause. The chance was very high – period illness.

It turns out that one chuditch from the outskirts of Perth was exposed to three different second-generation rodents. At 1.6 milligrams per kilogram, there was a level of one poison, Brodyfacombe, far exceeding the rates estimated to be lethal to mammals. This could be the highest recorded exposure rate for Australian marsupials.

Approximately 5% of Tasmanian demons were exposed to fatal levels of these second-generation poisons, with an additional 10% being exposed to potentially fatal levels.

Even if these poisons don’t kill cool or demons directly, they can get worse.

All five are threatened. In other words, the population is only a small portion of the former population. Even small changes to the population can cause more rapid declines.

Our analysis shows that an increase in deaths of just 2% to 4% of deaths could increase the risk of extinction by 75%. This figure is extended by the total number of rats at risk of poison, which estimates 22% of a particular population in each generation based on the exposure rate here.

Therefore, exposure to rat venom alone may be sufficient to tilt towards extinction, even without other threats, such as being killed by foxes or cats.

Can poison be too strong?

The poison remains deadly for a while after killing mice and mice.

The poison we investigated takes several months to halve the toxicity. This means that during this time they can kill medium-sized mammals such as owls, reptiles, frogs, and possums.

There is growing evidence in Australia and around the world that these second-generation rodents kill more animals than targeted animals. The poison bumps into a wide range of carnivorous animals, including otters, wolves, foxes and raccoons. Even the famous California condors are threatened by the rodenticides.

The efforts to use thousands of liters of bromagiolon to stop the mouth plague in New South Wales have sparked strong criticism. But so far, criticism has done little to curb their use in Australia.

Australia is an outlier on this issue. In European and North American countries, these products are restricted to use by licensed pest control companies and are prohibited for use in the home. Some countries are going even further, banning these poisons entirely. However, here you can buy it at Bunnings, Coles or Woolworths.

Last year, a delegation of Australian researchers lobbyed politicians to do more to regulate the use of these poisons.

The person responsible for ensuring that the poison is safe is the Australian Department of Pesticides and Veterinary Medicine. Officials are now weighing their decisions on whether to introduce restrictions on these second-generation poisons, expected in April.

Four other Australian species under threat – Tasmanian wedgetail eagle, Tasmanian masked owl, powerful owl, and black parrots of Karnaby have previously been exposed to these rodents That was what I knew. Our study accepts this tally into nine threatened species.

Without regulations, you can make a difference at home. Do not use second-generation poisons that rely on Brodifacoum, Bromadiolone, Difethialone, Difenacoum, or Flocumafen. Remove problems in mice or rats with first-generation toxins containing warfarin, comatetol, or other chemicals.

If you only have one or two mice, consider looking at a non-point alternative.

Taking a little time to consider these alternatives can save Australia’s most threatened native predators from painful death.

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