Confirmed: Flaco killed by the poison paradigm

The texts started pouring in Monday evening. The New York Times (NYT) published the results of probably the most anticipated animal death investigation in recent memory. According to the Times, “toxicity tests determined that Flaco had been exposed to four different anticoagulant rodenticides that are commonly used for rat control.”

Flaco poses on a grassy field. c/o @jacquelineuws

The article did not confirm the active ingredients; however, it is likely that second-generation anticoagulant rodenticides (SGARs) are among the culprits. To review, “SGARs” is an acronym referring to four active ingredients (brodifacoum, bromadiolone, difenacoum, and difethialone) developed in the 1970s. According to the EPA’s website SGARs, “pose unacceptable risks to non-target wildlife.” Flaco was also suffering from a pigeon herpesvirus, which he contracted from feeding on feral pigeons in addition to rats during his year outside captivity.

In the 1990s and 2000s, poison control centers across the United States received tens of thousands of reports of children accidentally poisoned by SGARs, nearly all under age 3. As I wrote in another article, the risks to children in underserved communities finally led the EPA to ban the sale of SGARs to consumers in 2015. However, they remain available to consumers via e-commerce sites, including Amazon. They are also widely and wantonly used by licensed pest management professionals (PMPs). 

Some PMPs will tell you that SGARs are ‘a vital tool’ for protecting public health. However, this statement is not supported by any study or empirical evidence. Indeed, New York City (NYC) officials authorized PMPs to apply nearly 40 tons of rat poisons in 2022 - 20 percent more than in the previous year. Rodent complaints to NYC health officials doubled to over 60,000 during the same year. 

Flaco eyes a squirrel. c/o Shutterstock

This begs the question, why have we used chemicals for over 50 years without proven effectiveness and an extensive collateral damage record? In short, rat poisons are big business. As Chris Sweeney wrote in his excellent article for the National Audubon Society, “the global market for anticoagulant rodenticides is expected to grow from $3.8 billion in 2020 to $5.8 billion by 2027, with the United States accounting for more than one-third of sales.” 

City and town officials often view the costs of poison-based pest management strategies as more palatable than long-term solutions like exclusion and prevention because the labor costs are minimal. The PMP sets out the bait boxes, walks away, cashes the check, refills the bait boxes, and cashes the next check–rinse and repeat.

There’s no need to dispose of carcasses and no way to provide any return on investment because, unlike with a snap trap or SMART box, the PMP cannot show how many rodents a bait box removed from the community. This is the poison paradigm we live with today, and it’s this toxic business model that killed Flaco.

Flaco’s necropsy concluded that the combination of the pigeon virus and rodenticide exposure “would have been debilitating and ultimately fatal, even without a traumatic injury, and may have predisposed him to flying into or falling from a building.” This statement validates the concerns of many observers who reasoned that although a traumatic impact was likely the proximate cause of Flaco’s death, the chances of Flaco sustaining such an injury increased as long as he survived on a steady diet of poisoned rats. 

The necropsy report further concluded that rodenticide exposure and the pigeon virus caused “severe tissue damage and inflammation in many organs, including the spleen, liver, gastrointestinal tract, bone marrow and brain.” So, while images of Flaco shared on traditional and social media showed a superficially healthy bird flying over the street of New York, the reality was that Flaco was disintegrating from the inside out.

Flaco’s story demonstrates another pernicious aspect of the poison paradigm. One PMP has often told me that rat poisons pose no threat to charismatic species like bald eagles, whose population has grown ‘unabated for decades’, despite the prevalence of SGARs in their environment. While we have only a handful of bald eagle deaths that are confirmed to have resulted from SGAR exposure, the fact is that the effects of these poisons are often not apparent until the animal is beyond saving. 

According to MSPCA-Angell, first-generation anticoagulant rodenticides (FGARs) persist in an animal’s system for approximately seven days, but SGARs remain in tissues for far longer–generally four weeks. This is a feature, not a bug. The developers of FGARs created SGARs as a more potent chemical successor that would inject enough poison into an animal’s system to kill it with a single feeding. Therefore, from a purely toxicological perspective, SGARs pose a greater threat to wildlife.

This new knowledge concerning Flaco’s death is immensely sad and unsurprising. We know the threat these poisons pose to public health and biodiversity. We now need to use this knowledge to create a more sustainable solution. Forward! For Flaco, for all.

Want to learn how you can protect Plymouth’s natural heritage from sharing Flaco’s fate? Join Rescue Plymouth Wildlife’s public kick-off meeting with Mass Audubon on 10 April at Plymouth Public Library. You can also email us at rescueplymouthwidlife@gmail.com.