UPDATE: This Thanksgiving (2022), it was discovered a lone survivor of the Great Horned Owl family residing in Menotomy Rocks Park that died this spring had attracted a new mate, spurring new hope we could have a thriving owl couple at the park. However, this hope was short-lived.
On December 4th, an owl was discovered collapsed on the ground by the pond in the park, coughing up watery blood. A wildlife rehabber was called in, but the owl died en route to the animal clinic, again widowing the surviving male owl. The rehabber reported that the blood they drew from the owl had still failed to clot even hours later, a sign of anticoagulant poisoning. Great Horned Owls often mate for life until one of the pair dies. They usually spend most if not all the year together–roosting in trees, preening each other, serenading each other, hunting together, feeding each other, and then raising their offspring together. Another Great Horned Owl pair in neighboring Belmont have been together for over 12 years. That this female died so late in the mating season means the male–whose natural place would be as part of a couple–will likely be alone for at least another year and not have offspring this upcoming season. This means this species is failing to thrive in our town due to the prevalence of rodenticide poisoning in our borders.
In summer 2021, a resident juvenile bald eagle in Arlington known as “C25” died due to rodenticide poisoning.
This means C25 likely ate rats that had fed on the poison that is available in bait boxes that can be found on most streets in Arlington against residential buildings, businesses, and homes.
The kind of poison in these bait boxes, known as Second Generation Anti-coagulant Rodenticides, or “SGARs”–are a kind of super poison that threatens our pets and wildlife. It was banned from over-the-counter sales in 2015 by the U.S. Environmental Protection Agency due to an epidemic of child poisoning. However, licensed pest control professionals can still deploy them in bait stations. This does nothing to stop secondary poisoning risks of animals such as foxes, owls, cats, hawks, coyotes, and eagles.
Unfortunately, wildlife deaths due to rodent poisonings are not tracked. As bald eagles are still a listed species under the Massachusetts Endangered Species Act, any bald eagle death in our state’s borders must be tested to determine cause of death. C25 was the second bald eagle to die in the area in just a few month’s time from confirmed rodenticide poisoning. The first one to die in 2021 was her cousin and died in Waltham.
More recently, a family of Great Horned Owls–namely, a mother owl and her two adolescent owlets–were discovered dead at Menotomy Rocks Park. Though a necropsy was not performed to officially determine cause of death, a field assessment pointed to rodenticides as the possible culprit (specifically, the owls were spilling bright red watery blood post-mortem, a usual tell-tale sign of anticoagulant poisons).
What can be done about poisons?
Fortunately, Arlington Town Meeting did pass warrants this past spring 2022 to phase out use of SGARs on town-owned and managed lands and properties, and adopt an Integrated Pest Management (IPM) plan that emphasizes poison-free alternatives to controlling rats and mice. The town also plans to ask the state for a waiver to also try to phase out rodenticide use by private landlords and businesses owners (currently the state does not allow municipalities to do this). But it’s not clear whether that will happen. In the meantime, you as a consumer can make sure to only use sustainable/humane alternatives to poisons in your own home and business, and ask your landlords or the businesses you patronize to do the same. With that in mind, we’re launching the Arlington Poison Free Pledge.
Petition to the Housing Corporation of Arlington to cease using rodenticides.
For more information about the impacts of rodenticides on wildlife, as well as alternatives to poisons for rodent control, Raptors Are The Solution, or RATS, is a great resource.