March 15, 2021

“By failing to account for starvation or other likely effects of frightening birds from a site, the [Environmental Protection Agency’s Draft Ecological Risk Assessment] for Avitrol is grossly incomplete.”

Read our full comment here.

Policy background

Many laws passed by the United States Congress authorize federal agencies to write regulations to execute and enforce specific details of the law. The Administrative Procedure Act directs agencies to develop regulations in a fair and accountable way (5 U.S.C. § 551). Among other things, it requires that agencies solicit and address public comments before adopting new regulations or changing old ones.

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that all pesticides sold or distributed in the United States be registered by the Environmental Protection Agency (EPA). As part of the registration process, the EPA publishes a preliminary assessment of risks the pesticide poses to the environment and invites the public to comment. The EPA must respond to all concerns raised in the comment period, after which it may decide to register the pesticide for general use, register it for restricted use only, deny registration, or postpone its decision until it has sufficient information to accurately assess ecological risks.

FIFRA states that a pesticide cannot “cause unreasonable adverse effects on the environment,” where the environment is defined as “water, air, land, and all plants and man and other animals living therein” (7 U.S.C. §136). Recent court findings indicate that negatively impacting animal welfare qualifies as an adverse effect on the environment.

Avitrol (4-aminopyridine) is a pesticide intended to frighten away birds by causing seizures in some members of their flock. The EPA previously authorized its use, but FIFRA requires it to regularly review each pesticide’s registration. As part of its review, the EPA published a Draft Ecological Risk Assessment and solicited public comments on it. The comment period closed on January 4, 2021.

Our rationale

Wild Animal Initiative submitted a comment urging the EPA to conduct more research before reregistering Avitrol and warning that the pesticide likely causes unreasonable adverse effects to the environment.

This was our first attempt to directly influence policy. Wild Animal Initiative’s overarching objective is to support the growth of an academic field dedicated to wild animal welfare. Our work typically consists of conducting original research, collaborating with academics, and securing funding for promising projects. But when we learned about the Avitrol review in the process of researching humane methods of pigeon control, we saw a clear opportunity to connect wild animal welfare research to active policymaking.

By law, agencies must read all public comments and to publish a response that addresses each type of concern raised. However, agencies are not required to take the advice of the public, and courts tend to defer to agencies when their reasoning is challenged. Because the likelihood of our comment actually changing EPA policy was so low, our main goal was to explore the federal rulemaking process as an avenue for further wild animal welfare advocacy.

In the long term, we would like the federal government to regularly consider the impact of its policies on wild animal welfare. That would require not only more political support for but also more scientific understanding of how to help animals in the wild. Even if the federal government isn’t prepared to optimally manage wild animal welfare, in the medium term it can help identify and incentivize research that could inform its decisions. And in the short term, if the government incorporates existing wild animal welfare data into some of its decisions, it can set a precedent for larger-scale action later.

Direct effects of Avitrol

Avitrol is used to control populations of various birds considered to be pests, primarily rock pigeons (Columba livia). It induces seizures in the affected animals (Gupta 2012), whose convulsions and alarm calls are meant to deter untreated birds of the same flock.

The manufacturer asserts that “the birds affected are not in pain” because they are not conscious during Avitrol-induced seizures. The seizures can last up to several hours (Gupta 2012), so the question of whether they are conscious and in pain during that time should be investigated further.

The affected birds may also experience pain or injury before or after the seizures. In humans, ingestion of Avitrol has led to nausea, shortness of breath, and "a feeling of impending doom" before the individual ultimately loses consciousness (Spyker et al. 1980). Birds who survive poisoning with Avitrol may also sustain debilitating injuries due to reduced motor control during seizures or delayed reaction times for up to 15 hours following ingestion (Gupta 2012).

Available data suggests that a large fraction of the birds who ingest Avitrol do not survive (Gupta 2012). The University of Missouri Extension says that even though Avitrol is classified as a frightening agent, “it can also be used as a toxicant in areas where bird mortality is acceptable.” Applicators can modify the mortality rate by blending Avitrol-treated bait with untreated bait.

Avitrol can harm non-target animals as well. Though animals who consume affected birds face little or no risk of secondary poisoning, Avitrol sometimes poisons non-target animals who consume the bait directly (McLean and Khan 2013).

Indirect effects of Avitrol

Because other wild animal advocates had discussed Avitrol’s direct harms in the previous stage of the review process, our main contribution was to call attention to its indirect effects.

According to the manufacturer, Avitrol is intended to function primarily as a deterrent and not as a method of population control. But even apparently harmless displacement could have cruel indirect consequences.

Pigeons are limited by food availability in urban environments (Stock & Haag-Wackernagel 2016). Displacing pigeons from one area will therefore require them to forage in an area where there will either be less food or more competition. Facing even tighter resource constraints, either the displaced birds or their new competitors will starve: a long and painful way to die.

Because starvation is a probable indirect consequence of Avitrol’s primary advertised function, we argue the EPA needs to evaluate this risk before it can legally reregister Avitrol. But considering indirect effects on wild animal welfare has much broader policy implications. Other bird deterrence methods described as humane might also cause starvation. Indirect effects are generally more likely to be overlooked or ignored, creating a need to institutionalize their consideration. Even if the EPA doesn’t yet have the data to answer these questions, it can require pesticide registrants to produce that data. This could help stimulate more research into policy-relevant wild animal welfare questions.

Alternative control methods

Because we are so concerned about indirect effects, we wanted to check whether restricting or banning Avitrol might cause even more harmful control methods to be used. Although more research is needed, the available evidence suggests that Avitrol is unusually problematic. It combines the direct harms of lethal methods with the indirect harms of deterrence methods without capturing any of the benefits of contraception methods.

Lethal methods

To our knowledge, the only avicide besides Avitrol that is registered for use in the US is DRC-1339, also known as Starlicide. DRC-1339 only be used by USDA-certified pesticide applicators, limiting its accessibility. Therefore, we do not expect that reductions in Avitrol use would be compensated for with increased use of DRC-1339 to any significant extent.

While the use of some lethal methods such as trapping and shooting may increase if Avitrol were restricted, it is hard to know by how much. Although some sources describe lethal pigeon control as pervasive, precise numbers are not available. More data in these areas would give us a clearer picture of how Avitrol restrictions would ultimately impact bird welfare.

Deterrents

Products such as spikes, nets, reflectors, and lasers are usually marketed as humane solutions to human-wildlife conflicts, although they sometimes do directly cause significant suffering, such as when birds get stuck behind nets. Because these deterrents do not directly reduce population size but rather displace birds from the treatment area like Avitrol does, they may still result in increased starvation. They seem preferable to Avitrol, however, because their direct effects on animals are typically far less unpleasant than the effects of Avitrol poisoning.

Contraception

Contraceptives can reduce populations without the pain associated with lethal methods. We have previously written about how contraceptives could even improve the welfare of urban pigeons by reducing resource competition and juvenile mortality. Further research is required to understand their actual impact on the welfare of both target and non-target animals, but we think contraceptives are probably the highest-welfare alternative to Avitrol. They are unlikely to completely replace other control methods, however, because people often want faster solutions to human-wildlife conflicts than contraceptive population control can provide. If fertility control replaced Avitrol use, we would expect it to be used along with deterrents.

Conclusion

It is illegal for the EPA to reregister a pesticide before it has sufficiently determined the pesticide “will not generally cause unreasonable adverse effects on the environment.” Both the direct effects of Avitrol — which seem more severe than the EPA has estimated them to be — and the indirect effects of Avitrol — which the EPA has not yet considered at all — seem likely to constitute unreasonable adverse effects on the environment. At the very least, the EPA needs to evaluate the risk of frightened birds starving to death, which could be Avitrol’s largest effect on animal welfare even though it is indirect.

We emphasized the importance of indirect effects because neither the EPA nor previous commenters had called attention to them, and because understanding indirect effects is a central challenge in wild animal welfare. By focusing on welfare rather than rarity or other kinds of value, the wild animal welfare perspective requires accounting for each affected animal regardless of species or location. Fortunately, after exploring this intersection of environmental policy and wild animal welfare research, we believe existing legislation may provide many more unexplored opportunities to compel the US government to consider wild animal welfare.

Acknowledgements

Michelle Graham and Simon Eckerström led the scientific research for Wild Animal Initiative’s public comment on Avitrol to the EPA, with assistance from Holly Elmore and Kim Cuddington, both of Rethink Priorities. Michelle, Simon, and Cameron Meyer Shorb contributed to writing the comment. Cameron and Paul Meyer Shorb contributed equally to the legal research.

References

Administrative Procedure Act. 5 U.S.C. § 551 et seq. (1946). https://www.archives.gov/federal-register/laws/administrative-procedure.  

Federal Insecticide, Fungicide, and Rodenticide Act. 7 U.S.C. § 136 et seq. (2018). https://www.govinfo.gov/content/pkg/USCODE-2018-title7/pdf/USCODE-2018-title7-chap6-subchapII-sec136.pdf. 

Gupta, R. C. (2012) Avitrol pp 561-563. In: Gupta, R. C. (Ed.). Veterinary toxicology: basic and clinical principles. Academic press. https://www.elsevier.com/books/veterinary-toxicology/gupta/978-0-12-811410-0.

McLean, M. K., & Khan, S. (2013). A review of 29 incidents involving 4-aminopyridine in non-target species reported to the ASPCA animal poison control center. Journal of Medical Toxicology, 9(4), 418-421. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3846978/. 

Spyker, D. A., Lynch, C., Shabanowitz, J., and Sinn, J. A. (1980) Poisoning with 4-Aminopyridine: Report of Three Cases. Clinical Toxicology 16(4), pp. 487-497. https://www.tandfonline.com/doi/abs/10.3109/15563658008989978?journalCode=ictx18&. 

Stock, B. and Haag‐Wackernagel, D. (2016). Food shortage affects reproduction of feral pigeons (Columba livia) at rearing of nestlings. Ibis, 158(4), 776-783. https://onlinelibrary.wiley.com/doi/pdf/10.1111/ibi.12385.