Rodenticides:

Rat poisons are a common tactic used by people who are having issues with rodents. The most serious of these substances are called second-generation anticoagulant rodenticides (or SARs) containing the active ingredients brodifacoum, bromadiolone, difethialone and difenacoum. These can only be used legally by licensed applicators (professional exterminators). Strychnine is used as a rodenticide, but can only legally be used to control pocket gophers and must be placed underground in gopher burrows. Strychnine should not be used to control mice, rats or ground squirrels. Any above-ground use of strychnine may lead to unintentional poisoning of wildlife and pets. Often, people using these chemicals don’t know of the dangers they are causing to owls and other raptors, wild mammals, and pets.

 

Rodents consuming these poisons typically do not die until several days after feeding and may continue to ingest more poison. The poison is then available to a predator or scavenger that eats the rodent. If the exposed rodent does not die, the poison can persist in its body for several months, and any animal that eats the rodent will ingest the poison. This is called “secondary” poisoning.

Many of the wildlife professionals in our Coalition report getting intakes of owls and other large raptors who, for all intents and purposes, have a healthy body composition, are strong, and have no sustained injuries. Intakes like this go rapidly downhill because of secondary poisoning – they’ve eaten a rodent who was poisoned.  It is important to understand the risks to birds, and many other mammals, when deciding how to control rodent populations.

 

Remember, barn owls, in a single night, can catch many rodents hunting. By poisoning the rodents (and therefore the birds), you’re eliminating a major resource and organic method of rodent control.  Even more concerning, the parent owls are also bringing back poisoned rodents and feeding them to their owlets.

 

Although our Coalition members who run a BOMP program may consult, research, and perform maintenance, none of our BOMP members will install barn owl boxes where known rodenticides are being used. One of our main goals is to help reduce the use of rodenticides. It would be highly unethical for any of our members to install a barn owl box in a location they know is using rodenticides.