By Lisa Owens Viani
In mid-August, a young turkey vulture wandered weakly onto an El Cerrito resident’s patio and vomited blood. Later that night, the bird died. Tests performed on his body at UC Davis were positive for Brodifacoum, an anticoagulant rat poison. One of the parent birds disappeared around the same time, and the neighbors that had been watching the young bird being raised for many weeks were devastated.
This scene is becoming all too common, with barn owls, Cooper’s hawks, great-horned owls, even skunks and endangered species like kit foxes and fishers being poisoned after eating poisoned rodents. Over the past several years, WildCare and many other wildlife rehab centers have seen a huge increase in the number of animals coming in showing symptoms of rodenticide poisoning: everything from skunks to squirrels to foxes, and raptors, our magnificent birds of prey. When these animals eat a mouse or rat that has eaten rat poison, they, too, usually succumb, bleeding to death internally.
As we restore our watersheds, we are not only improving water quality but also providing important habitat for wildlife. Restoration efforts are bringing birds back. Amazingly, barn owls, Cooper’s hawks, white-tailed kites, and sharp-shinned hawks are thriving in many East Bay cities; great-horned owls hunt and raise their young in our regional parks, and peregrine falcons have made a comeback all around San Francisco Bay. These top-level predators can offer important services to humans–if we let them live and do their work. For many of them, that work is rodent control. One family of barn owls can consume 600 mice in 10 weeks.
One reason rats and mice may be flourishing these days is because backyard bird feeders and chicken coops have become ever more popular, providing an easy food and water source. When people see rats, they tend to look for easy answers–and quickly reach for some D-Con or other equally dangerous product. The problem and solution are then easily “out of sight, out of mind”–until a dead Cooper’s hawk turns up on your sidewalk or your dog needs to be rushed to the vet. By using poison, we are killing one of the most important solutions to the problem–birds of prey. Skunks, opossums, and native mammals will also eat mice and help control their populations.
We need to make sure we aren’t inviting wildlife into our back yards only to poison them. To discourage rats, rip out your ivy and replace it with natives; sweep up bird seed (or put a tarp underneath your feeder and empty it every night), and build a rat-proof chicken coop. Consider feeding birds with blocks of seed mixed with suet (less seed drops on the ground) instead of bulk loose seed, and make sure to use a baffle. Don’t leave pet food outside. Practice good housekeeping, and if you’re still having a rodent problem, use very carefully placed snap traps–the only effective and non-toxic solution currently on the market.
We have a choice: to use poison or share our world with wildlife–we can’t have both in any sort of sustainable way.
Photo credits: Turkey vultures by Todd Backman
Editor’s Note: In a previous version of this story, we suggested that opossums are native to California. While they are quite prevalent here on the west coast, there is only one species native to North America and that is Didelphis virginiana, more commonly known as the Virginia opossum because that state is where it was first spotted.