Poison Bait Station
A typical poison bait station set out for rodents, this one next to a fence near Pine Meadow Ranch. photo by Jim Anderson
People who use poison bait stations to eradicate rodents are barking up the wrong tree. First, and most important, there’s a question about the poison itself. In the literature supporting the use of this deadly bait they say, “…and the rodent goes off and dies.”

Exactly, the rodent does go off and die — but sometimes it staggers into the storage area of the bait box and dies there. If that happens with the poison station set up against the wall at the Sisters Elementary School something terrible could happen.

Burrowing rodents of Central Oregon — as well as our house-dwelling pack rats —have been identified as hosts of the flea that transmits bubonic plague, aka Black Death. That includes our beautiful forest tourist attraction the golden-mantled ground squirrel. Millions of Belding ground squirrels killed throughout summer by sage rat hunters as well as gophers, voles and other rodents found underfoot are also disease carriers.

Several years ago a child on the Warm Springs Reservation died of bubonic plague when her cat brought into the house a dead Belding ground squirrel it had killed. A plague-carrying flea jumped off it and bit the child, transferring the plague to her. In October of 2015 another child died of the plague in Oregon who was on a hunting trip near Heppner, undoubtedly from a flea that found the child’s warm body more suitable than the rodent it had been on.

A poison bait trap could act the same way if a rodent carrying the plague died of poisoning. The flea would leave the animal when it cooled and go searching for another warm body. In a public place, hundreds can pass a trap every day.

Then there’s the poison used to kill the rodents: if it’s Brodifacoum, it will continue killing long after the rodent dies. It’s a poison that rodent-killers love to use because when the victim eats it, it/they will die quickly. But before it dies, it could wander away from the poison bait station. Then what?

Brodifacoum is a highly lethal anticoagulant poison that has become one of the world’s most widely used pesticides. It’s typically used as a rodenticide, but is also used to control larger “pests” such as coyotes and badgers. Brodifacoum is also persistent in soils with a half-life of 157 days, and if spilled could get into ground water easily.

The secondary killing by Brodifacoum victims is the reason two baby eagles died very near Sisters. The parents returned to the nest with a rodent that had died on the surface after ingesting Brodifacoum, fed it to the nestlings, and in a short time they, too, were dead. That nest is empty this year and it’s not too difficult to guess why…

There are several eagle nests around Central Oregon that have been producing golden eagles for over 50 years that are empty today. The opinion of wildlife biologists is that those eagles may have ingested Brodifacoum in the body of a dead ground squirrel, or may have died from poisoning in a ground squirrel containing lead from the ammunition used to kill it.

When it comes to poison bait stations, it appears the new Sisters district ranger, Ian Reid, inherited a situation that on the surface appears to be a mundane case of eliminating a few animals that the Metolius homeowner(s) didn’t like, or lived in fear of. But in reality the poison has been causing serious damage to a section of the Metolius River riparian ecosystem.

That’s the trouble with most poisons — they keep on killing non-target victims. The local hardware stores carry an amazing number of products available to kill animals. It could give one the feeling our whole world was about to be taken over by these tiny rodents and someone shouted, “Kill ’em all!”

There are Sweeney’s poison peanuts that’ll kill anything that eats them; same for their plastic life-like worms. And then there’s the blaring statement, “GUARANTEED TO KILL! on d-Con’s stuff. Ramik’s poison Mint Bars and Green Mini Bait are attractive — and deadly — to any bird or mammal that lives on the forest floor.

There’s “Tomcat” (what an appropriate name for all the feral and house cats that are out there killing state-protected wildlife) offered on Google. It runs $23.98 for a 4 lb. pail. At the end of the list on Google there are 24 other suggestions for killing rodents. Getridofthings.com is an example.

A spokesman for the USFS Sisters District said, “I, along with others on the District, have noticed more and more bait boxes in the Metolius housing area and we too feel the need to address this issue. One-on-one conversations with cabin owners have not solved the problem; the poison stations are still there.”

With the encouragement of local resident Susan Prince, Sisters District Ranger Reid wrote a letter to the Metolius Association homeowners, stating the rules very clearly about the use of poison stations. Problem is that few people read these emails and, in the meantime, more chipmunks are being killed, and more non-target animals are getting poisoned; including one protected by Oregon State law, the golden-mantled ground squirrel.