This spring a rash of owl deaths prompted a closer look at rodenticides (rat poison). Almost a dozen owls died around Tampa Bay, all resulting from eating rat poison, according to necropsies.
“These recent owl deaths were highly visible, but the problem is astronomical,” said Nancy Murrah, founder and president of the Raptor Center of Tampa Bay.
“We know the symptoms (of poisoning) well and see many birds we suspect are dying from it,” she said. “But with necropsies costing $250, we can’t afford that for every bird death we see.”
“We see hawks, eagles or other raptors dead on the road – hit by a car,” she said, “but why were they so slow? These poisons bio-accumulate over time, so we think most raptors have toxins.”
The death of a beloved family of great horned owls in Safety Harbor’s Phillipe Park triggered the recent alarm. The pair, dubbed Emily and Oliver, were raising two owlets called Huey and Louie. For almost seven years the pair nested in the “Owl Tree”, which became a gathering place for nature photographers.
But these weren’t the summer’s only owl fatalities in Tampa Bay – four more nesting owls perished in Dunedin’s Hammock Park, another in a South Tampa park, and one in Manatee. All showed toxic levels of rodenticides when necropsied. The owls accidentally ingested a toxic dose by eating poisoned rats, raising serious concerns about rodenticides in state parks and other public areas
The popular anticoagulant rodenticides (ARs) leave the rat wandering around as it bleeds out, providing a tempting, slow-moving prey for an unsuspecting predator, who may gobble it up or share it with its family.
It may be their last meal.
In the U.S., the prevalence of ARs in non-target wildlife is widespread, with raptors a special concern because of ARs. A recent study at Tufts University’s found 100% of raptors they studied had traces of ARS. The EPA considers ARs so dangerous they tried to keep them from store shelves.
Often, manufacturers flavor rat bait with peanut butter to make it more attractive, sometimes drawing squirrels and other non-target species. Urban areas with restaurants and grocery stores regularly bait parking lots.
Fatally poisoned rats also affect non-target animals, even coyotes and panthers, because one rat can poison other mammals through bio-accumulation. It’s considered a danger to household pets, especially cats, who may catch a dying rodent.
Fortunately, Pinellas County has banned the use of rodenticides in all parks, and local governments in Safety Harbor and Dunedin have replaced rodenticide bait with snap traps that kill rats immediately.
In St. Petersburg, advocates want a moratorium on ARs in parks.
At Boyd Hill Nature Park in south St. Petersburg, Jason Cowen oversees the Raptor Center and shared concerns about neighbors using rodenticides that could affect park wildlife.
“We don’t use them, but we’re surrounded by a golf course and residential neighborhood,” he said. “If they use rat bait, the hawks, owls and other raptors could be poisoned.”
Cowen said the Sierra Club has approached area governments to protect raptors and other predators of small mammals by using snap traps, sparing rats the slow, painful death, and minimizing exposure to non-target animals.
In Gulfport, Tom Nicholls, director of Public Works, said they contract pest control out to local firms. After speaking with The Gabber, Nicholls asked the contractor what they used. When he learned they used ARs, he told them that was no longer acceptable.
“I’ve told them moving forward we’ll go in a different direction,” Nicholls told The Gabber, adding that, as needed, the City would use snap traps instead.
“We recommend snap traps,” Murrah said. “They’re far more humane; they kill the rat right away. Some people prefer humane traps, relocating the rodents in a more rural area with natural predators and fewer easy food sources.”
Other methods of rodent control include not leaving pet food outside, covering garbage cans, and plugging holes to keep rodents out of homes.