Chemists working on not killing other wildlife with rat poison

Ferringous Hawk

Fierce Ferringous Hawk

Some good news for lovers of birds (especially birds of prey), squirrels, pigs, and all kinds of predator mammals. Chemists are trying to figure out how to develop a rat poison that will only kill rats. Chemical and Engineering News says a few teams are working on the project, but right now they are just working out how badly rat poisons hurt other animals. (Answer: worse than many thought.)

Rat poison has been a huge issue for wildlife lovers, especially in cities. In New York City, the parks department has put restrictions on itself, but many of the city’s most beloved park animals–red-tailed hawks and squirrels–get wiped out just the same. Vancouver scientists have been trying to figure out exactly how many owls they are unintentionally killing. The deaths of hawks, falcons and owls are all the more tragic because these are the very animals that would provide natural pest control if people would stop throwing poison around the landscape.

The most popular rat poisons are anti-coagulants that cause animals to bleed to death.  Metal phosphides, which produce a poison gas in rat intestines,  remain in water and hurt lots of birds (especially geese, larks and ducks) and other mammals, Cornell says. Calciferols (vitamins D) make rats overdose on calcium. to see if they’re safe to humans) and Bromenthalin is a neurotoxin vets are seeing more of in pets since certain anticoagulants were banned for home use.

So far no one’s come up with a better rat poison. But the 6th International Chemical Congress of Pacific Basin Societies in Honolulu had a bunch of scientists working on at least figuring out how badly rat poisoins were killing nontarget species. The big innovation is they put out various dyes in bait stations to see how the poison would get through the food chain.

William Pitt, a research wildlife biologist with the USDA’s animal-killing department (Wildlife Services), is based in Hawaii and working out how not to poison the island’s feral pigs, which people and dogs might eat.

with the U.S. Department of Agriculture’s Wildlife Services National Wildlife Research Center, is simply tracking whether and how much of a rodenticide is being consumed by rodents or by other animals. So far he’s only been able to show that rat poison in feral pigs wouldn’t hurt humans–even if a pregnant woman ate ridiculous amounts of feral pig liver.

Birds aren’t so lucky.  Barnett A. Rattner, a wildlife toxicologist at the Patuxent Wildlife Research Center, in Beltsville, Md., studies rat poison exposure in the American kestrel and the eastern screech owl, which eat rodents.

Here’s a scary thought: In France, one-quarter to one-half of rodents are resistant to anticoagulants, Philippe Berny, a professor at VetAgro Sup says. Well, that’s one way to get people to stop using Warfarin.

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