This is in response to “Poison Bait Perils”. I wanted to further the writers’ request for the responsible use of poisons in the hope of helping to prevent the unintentional deaths of children, pets, and wild animals including owls, hawks, and other birds.
Modern poisons can be lethal not only to an animal that ingests them directly, but also to an animal that comes in contact with or eats an animal that has ingested poison. For example, part of a poisoned rodent dropped in a backyard by a crow and then eaten by a family pet could kill all three animals.
Products containing what are called second-generation poisons are more powerful and stay in body tissue longer than those containing first-generation poisons. Because poison bait does not kill animals right away, they continue to eat and build up a massive doses in their systems by the time they are found and sampled by another animal before or after they die.
There are effective nontoxic methods of eliminating animals we consider pests without threat to domestic animals or wildlife. But if people want to use poison, those most likely to kill unintended victims are second-generation anti-coagulants. Products that contain the second-generation chemicals bromadiolone, brodifacoum, difenacoum, and difethialone are now mostly restricted to use by professional exterminators. First-generation poisons available to consumers that also carry a higher risk of secondary exposure are diphacinone and zinc phosphide.
You can find more details about controlling animal populations or about the chemicals in poisons here: www.saferodentcontrol.org/site/problems-with-rodenticides/ and here: www.urbancarnivores.com/poisons/. I hope this helps.