“Most rat poisons kill more than rats — they also pose a fatal threat to birds of prey . This issue should not only get attention when a culturally iconic species like a bald eagle dies. Nearly every raptor species is vulnerable to rodenticide poisoning, from eastern screech owls to red-tailed hawks.”
— Massachusetts Audubon
Next time you visit a shopping center, office park or downtown, look around for black-plastic boxes that resemble shoeboxes, only a bit flatter. They are so common they have become an invisible part of the New Jersey landscape.
The vast majority of these black boxes, known as “rat bait stations,” contain some of the nastiest poisons around, and they kill more than rats. They also kill or weaken any great horned owl, bald eagle, hawk and other wildlife that eats rats.
As New Jersey develops its open spaces, raptors must increasingly try to adapt to suburban and urban areas. The rat poisons they encounter there could mean a dim future for many of these magnificent birds.
Our state’s raptors have fought back from the ravages of DDT. Now, they must fight back from rat poison.
The deadliest poisons are called second-generation anticoagulant rodenticides, and here’s how they work:
A rat enters the black box, eats the bait and leaves. The rat poison slowly takes effect, preventing the rat’s blood from clotting, and the rat slowly bleeds to death. In its weakened state, the rat is an easy meal for a hungry owl or hawk. And the raptor eats the poison inside.
Sometimes the poison kills the raptor outright. Other times, the raptor eats sub-lethal levels that accumulate in its system, like DDT. The weakened wildlife is more likely to die from other causes.
These poison dispensers were designed as the last resort when curbing rats. Instead, they have become the go-to solution, often ignoring the underlying causes. Notably, many restaurants and other businesses that use these rat-poison dispensers often leave their Dumpsters open or put their garbage in plastic bags — significant reasons for the rat upsurge in downtown Montclair. These free buffets attract more and more rats, creating an endless cycle of rat infestations — and poisoned wildlife.
How serious is the problem?
In New Jersey, The Raptor Trust, the premier avian rehabilitation center in our region, no longer sends raptors that likely died from rat poison to the state for testing, for one simple reason.
“We are all aware of the poisoning issue, so from my perspective, identifying one more bird that has succumbed to poison doesn't do much except confirm what we already know,” Raptor Trust executive director Chris Soucy wrote in an email.
Nationally, The EPA has banned these poisons for household use — but the poisons are still widely available online.
A study released earlier this summer by Cornell University found that two-thirds of the red-tailed hawks tested in New York State have anticoagulant rat poisons in their systems.
A 2021 University of Georgia study tested 116 bald eagles and 17 golden eagles for the presence of these rat poisons. Researchers found rat poison in 82% of the eagles.
An earlier study in NJ found residues of the worst types of rat poisons in 81% of the red-tailed hawks and 82% of the great horned owls tested.
According to State Wildlife Veterinarian Dr. Nicole Lewis, New Jersey is taking a closer look at these poisons. “We’re currently doing a study on eagles. We’ve collected 100 liver samples from them for several years, and they are in the process of being tested.”
She says that rat poisons have been detected in many of the samples so far, and that a recent New Jersey study on bobcats found residual rodenticides in this endangered species as well.
Opposition to these second-generation anticoagulant rodenticides is growing across our continent. California and British Columbia have placed moratoriums on their use, and Massachusetts is considering a similar step.
A dozen prominent environmental groups are asking Bergen County to pass a resolution opposing these poisons, as the Borough of Allendale has done. We are building a grassroots movement to expand our efforts statewide.
New Jersey residents have worked together to do great things for wildlife, protecting and preserving habitat, banning DDT, cleaning up the water environment and helping to bring back such iconic raptors as the peregrine falcon, the bald eagle and the osprey.
We need to join together once again and reduce the threat of rat poison to our wildlife.
Jim Wright is a long-time nature writer and “Bird Watcher” columnist for The Record. Don Torino is president of the Bergen County Audubon Society.