22/11/2024
Long story short: the companies that leave rodent poison are lying when they say “the dose is so low it won’t hurt anything further up the food chain” that’s completely untrue. We get tons of animals with rodenticide poisoning every year (foxes, owls, hawks) and many don’t survive.
These animals take down way more rodents than bait boxes do! If you keep poisoning them the rodent problem will only get WORSE!
In just the past week, while dealing with all these dead owls, I have heard from no less than five different people that pest control cos told them or their neighbors that wildlife are not impacted because the dose of the bait a mouse or rat eats is too small to climb up the food chain. So, let me as an academically trained wildlife biologist whose research focus was predator-prey dynamics--explain why this is utter BS.
First, let's talk briefly about SGARs--it's a second generation rat poison. The reason there's a second generation is because rats and mice already started developing a lot of biological resistance to the first generation.
Rats and mice are also smart and if they get sick immediately after feeding, they learn to avoid that food and will communicate that to their kin. Sounds like a Disney plot or the Secret of NIMH. But we need to understand animals--including rodents--are often a lot smarter than we give them credit for.
So for the SGARs, not only were they developed to be hella more toxic than the first gen stuff--where it can kill a rat or mouse with a single feeding BUT there's a lag time. That is, while a single dose/feeding is supposedly fatal--it doesn't actually kill that rodent for many days--sometimes more than a week after that feeding. This is on purpose--so rats and mice don't associate the bait with feeling sick.
This means that rat or mouse can and will feed many, many, MANY times not just from a bait box, but from all the others (since they are everywhere and why do you think a pest co never puts down just one?) that have these poisons--at different rates and combinations.
For days and days the rodent feeds....before it kills them.
That is even IF it kills them. What do I mean "IF"? Well....
Because as with the first gen, biological immunity has already been documented in some populations of mice and rats with SGARs. That means some of these mice and rats are eating it indefinitely and it may not even kill them. At all. Or it could take weeks or months to show effect.
So those of us using SGARs? Congrats, we are creating super resistant rats.
See, rats and mice are such prolific breeders: They are having hundreds of babies a year. They can outbreed the poison.
But here's the critical thing: their predators CANNOT outbreed the poison. Their predators cannot develop biological resistance.
So we're both creating super resistant rats while killing off our natural pest control that is not resistant.
Bravo pest companies. Bravo, you're decimating your best competition in reining in rats. The hawks, the owls, the foxes.
Because here's the thing--a single Great Horned Owl--two of which have DIED in our area just in the past 12 days of rat poison--can each kill 5,000 mice and rats a years. No poison can compete with that.
Rats can't build biological immunity to predators. They can't learn to avoid them by association--because these predators have evolved over millions of years to get their prey.
So let's return to the original math equation.
A mouse or rat eats many, MANY times the fatal dose of multiple SGARs (which also have a compounding effect).
+ And then you have a hawk or owl, which eats dozens of rodents in a week or month.
(So you have a mouse or rat with dozens, if not potentially, hundreds of times the fatal dose of SGARs in its system. Then you take that and multiply it by dozens more times, because a hawk or owl will eat many of these rodents with these high amounts of poisons in their system).
= You get poisoned predators dropping dead in droves.
= We now have more and more and MORE rats, super resistant without enough predators to tamp them down.
Not to mention, there is a phenomenon known as "bio-magnification"--that is--a chemical concentrates at HIGHER doses more rapidly in the liver as it moves up the food chain.
Pest companies don't seem to grasp this, or they just don't care. And that's not just my conclusion. In 2017, there was a survey done of 2 dozen pest cos in MA. ALL of them dramatically underestimated the secondary impacts of SGARs. None of them seemingly understood the biological realities of how they work up the food chain. Almost all of them used SGARs as a "first line" method of control. Yet all of them also called themselves IPM professionals.
People don't have to take my word for it. The data my coalition submitted to the Pesticide Board shows the results of dozens and dozens of necropsies and liver tests of owls, hawks, coyotes, foxes, loaded with rodenticides at levels often considered fatal for those species and whose bodies showed internal bleeding--sometimes massive amounts. That data is public record.
