Conservationists from the Seattle Audubon Society have expressed concern over the number of Seattle-area owls and hawks that have been turning up dead and full of rat poison lately.
The rodenticides these conservationists find inside the raptors are second-generation anticoagulants, and they're effective at keeping rodent populations under control. The poisons, however, which kill via internal bleeding, often harm more than just rats.
Back in 2015, the Environmental Protection Agency banned the poison for non-commercial use because 15,000 kids per year are endangered from ingesting the stuff. This year, California's state legislature passed a bill to temporarily ban the poison altogether because it was winding up inside birds, mountain lions, and other wildlife. The Washington-based Urban Raptor Conservancy said it finds the poison in around 90% of necropsies on dead birds.
Right now, hundreds of nondescript bait boxes loaded with this poison await their victims around the city, mostly in parks and business districts. But a budding partnership between birders, city officials, and a duo that is extremely concerned about a snowy owl is trying to force the city to kick its rat poison habit for the sake of Seattle's birds.
The two poison alternatives under consideration? Gas the rats, or give them birth control.
"I timed a rat that was hemorrhagic and it took 12 hours for it to die"
The arrival of Yuki inspired Kersti Muul, a Seattle Audubon conservation committee member and the organization's rodenticide lead, to invest time in finding rat poison alternatives.
"I don't know if you're aware of her," Muul told me, "But Yuki is a snowy owl who showed up in West Seattle last year."
I did vaguely remember last autumn's snowy owl frenzy, but I did not know the bird had a name, nor that she'd taken up a permanent address. Yuki, it turns out, flitted around Seattle for a bit before settling in Queen Anne, a block away from the business district.
As part of her work with Raptors Are The Solution (RATS), a group trying to raise awareness about rat poison bait boxes, Tanea Stephens and Seattle Audubon keeps a Google Maps survey of all the bait boxes she and other volunteers find in Seattle. With Yuki so close by, Stephens surveyed the Queen Anne business district and found 70 bait boxes just on Queen Anne Avenue. "That's 1,300 pounds of poison," Stephens said.
And that poison is powerful. Rats scuttle inside the boxes, eat tainted bait, and then scuttle back out. After a while, the anticoagulant kicks in. The chemical slowly causes the animal to bleed to death internally. The rats lumber around outside, vulnerable and juicy with poison—easy pickings for birds of prey.
"I timed a rat that was hemorrhagic," Muul told me. She watched as the poisoned animal wandered around "out in the open" during hours when barred and screech owls were active. "It took 12 hours for it to die."
With all this poison lying around, Muul and Stephens started to worry for Yuki, because snowy owls eat rats.
They developed a short-term and a long-term plan; one "ready to go in case Yuki showed symptoms" of eating poisoned rats, and another to ween the Queen Anne Business District off of rat poison and onto ContraPest, or rat birth control.
Muul and Stephens, in partnership with the FYX Foundation, plan to lay stations filled with a liquid that temporarily stops female rats from producing eggs and that also deforms the sperm of male rats. By cutting off the animal's ability to reproduce, they hope to reduce the area's rat population by 40%.
But first, Muul and Stephens need buy-in from the local businesses. This week they sent around a letter to 62 landlords and business owners, asking them to ditch their poison and to try out rat birth control. If the pilot is a success, Muul and Stephens want to expand the strategy citywide. They've already received the support of District 7 Councilmember Andrew Lewis, Stephens said.
"It's a really ratty park"
At the city level, Seattle Parks and Recreation is trying out its own poison alternative in three of Seattle's rattiest parks.
As any resident could tell you, Seattle's parks are filled with rats—but some are rattier than others.
Cal Anderson Park is a rat haven, according to Josh Morris of the Seattle Audubon. At night in that park, "you’re skipping along with the rats," Morris said. If you pay close attention, you can even spot all the rat burrows that have "torn up the landscape" in the park.
"There’s a tree on the left side of the park that has a burrow in it," Morris explained, "and you can see a scar in the turf that a rodent has etched into it. It’s a really ratty park."
Parks and Rec knows of Cal Anderson's ratty reputation, and they have a pretty big rodent control presence there as a result. Currently, Morris said, there are around nine rat poison bait boxes on the grounds.
But Morris, who is trying to create a habitat corridor for birds and pollinators along 11th Avenue on Capitol Hill, has been working with the city to find a bird-safe rat control solution. The plan? Plug up all the rat burrows in an area except for one, insert a canister of carbon dioxide into the open hole, and then let it rip. Gas the rats in their own homes.
"The gas sinks into the burrows and the rodents won’t be able to escape," Morris said, "and they'll suffocate in their dens." That solves the issue of airborne predators snacking on rat carcasses.
Patricia Bakker, the manager of the integrated pest management department within the Parks department, said this gassing pilot program is currently active in three Seattle parks that have been dubbed "rodent hot spots." Those ratty parks are Denny Park, Albert Davis Park, and Cal Anderson Park.
Bakker is confident that the pilot will expand across Seattle's parks, replacing rat poison boxes. At this point, the pilot is pretty much just determining whether it's more cost-effective for the city to gas the rats themselves, or to contract with someone else to do that.
Bakker said she's also trying to introduce "rodent-proof receptacles" to keep rats out of the trash in parks and reduce rat numbers.
Morris said he feels "optimistic" about the work the city is doing, and about how that work will impact local birds.
Okay, hear me out: I'm not sure if anyone's considered it, but maybe if we phase out the poison, the city could employ a team of municipal falcons to control pests? I dunno, just an idea.