The Disappearance of British Columbia's Birds
The Disappearance of British Columbia's Birds: A Summary of Independent Research Seeking the Truth About Raptor Mortality and Rodenticides.
Our independent research has raised serious concerns regarding the welfare of B.C.’s wildlife. Lack of organization, proper data collection, and breach of professional standards demonstrate a catastrophic failure within government agencies responsible for monitoring environmental health, wildlife protection, and the use of hazardous products. The systems in place for monitoring the scope of risks and consequences of rodenticide products are by all measures inadequate. As a result, B.C. continues to lose more birds and other animals while long-term, cumulative effects on ecosystems and human health[1] are flagrantly ignored.
When the deaths of numerous owls came to the public’s attention in 2019, questions began to arise regarding the legal, regulatory, and enforcement mechanisms in place around rodenticides in B.C.. In an effort to better understand how rodenticides affect wildlife and raptor species in particular, avian necropsy reports performed by B.C.’s Animal Health Centre (otherwise known as the Animal Health Lab) from January 2017 through November 2020 were requested through the province’s Freedom of Information process.
As a diagnostic laboratory considered part of the Plant and Animal Health Branch of B.C.’s Ministry of Agriculture, the Animal Health Centre’s mandate is to provide diagnostic, monitoring, investigative, surveillance and regulatory programs for the province’s animal populations. In their position with this laboratory, pathologists responsible for the necropsies analyzed herein have a professional duty to approach diagnostic analyses with a reasonable degree of care. As demonstrated below, such care has not been exercised. These inadequacies have resulted in grossly underestimated statistics related to the presence of rodenticide products in the environment and their role in wildlife mortality. Our analysis of the Animal Health Center’s reports and their accompanying processes has only led to greater confusion and concerns for B.C.’s wildlife as well as the government’s failure to monitor and mitigate unreasonable environmental risks.
Signs and symptoms deemed “consistent with anticoagulant rodenticide intoxication” by the Province’s own pathologists[2] are almost always disregarded for purposes of testing and diagnosis. Toxicological analyses are rare (33 of 300 raptors were tested for the presence of rodenticides), and circumstances where poisoning is suspected but never explored nor referenced as a part of the diagnosis are common.[3] Even if the presence of rodenticide(s) is confirmed, trauma, hemorrhage, emaciation, or a combination thereof are often listed with no mention of toxicants.[4] Additionally, many birds that exhibit classic signs and symptoms of rodenticide poisoning with no other identifiable cause are never tested for the presence of rodenticides.
Exhibit 1: Example cases where rodenticide toxicity was not tested nor mentioned as a possible contributing factor despite showing classic signs and symptoms of rodenticide poisoning and no other identifiable cause.
It is difficult to understand how the dismissal of key facts relating to the possible role such highly and acutely toxic compounds played in the death of these animals could be justified. Perhaps it is possible that the pathologists believe their reports will be updated as data from body parts nearly always retained for third party analysis are returned. However, it is our understanding that the scientists contracted to complete further analysis have no intention of providing toxicological test results that would enable these updates.[7] According to Laurie Wilson,[8] scientists have been collecting this data since 1989: however these findings are never resubmitted to the government. While the eventual publication of a scientific report may provide some insight as to the underlying data, it will not serve to inform the public about the presence of these products in our ecosystem and the direct and indirect impact on Avian species.
Considering that the Animal Health Centre outsources some of its laboratory testing to the University of Guelph’s Animal Health Laboratory (“UofG Laboratory”), it is possible that the Province’s pathologists are conforming to the following comment included near the bottom of all UofG Laboratory reports:
The diagnosis of AR intoxication requires both the presence of one or more AR in appropriate samples (e.g., livers or serum) and antemortem or post-mortem evidence of coagulopathy unrelated to another identifiable cause of hemorrhage (e.g. trauma).[9]
Thus, it seems to follow that when an animal has signs of injury, rodenticide screening is not requested by the pathologist responsible.
Such a rigid definition of AR intoxication is inconsistent with the approach Animal Health Center Pathologists take in assessing other, non-rodenticide diagnoses. It is not unusual for secondary factors believed to have played a role in an animal's ultimate death to be included in a diagnostic statement.
Exhibit 2: Examples of secondary factors included in a diagnostic statement.
Presumptuous diagnoses based on body condition prior to and regardless of a traumatic event seem to be common practice. For example, report 19-0418 involving a Great Horned Owl that exhibited multiple bone fractures upon discovery in an industrial exhaust concluded that emaciation -not trauma-was the cause of death. That is, the pathologist inferred emaciation based on gross findings related to reduced muscle mass and adipose tissue. Similar inferences are applied in numerous cases.
Exhibit 3: Example cases showing presumptuous diagnoses based on body condition prior to injury.
At the same time, contradictory logic seems to be applied in cases where rodenticides are suspected to have played a role or contributed to vulnerabilities that led to death. That is, where fractures or signs of trauma are present, individuals are not sent for toxicity testing even if pulmonary, thoracic and abdominal hemorrhage (i.e., signs and symptoms consistent with anticoagulant rodenticide intoxication) are observed (Report 18-1528). Community requests for toxicity testing where circumstances suggest rodenticide poisoning have been similarly disregarded (Reports 20-8634, 18-6869, 20-842, 20-6384, 20-7086, 20-7084, 20-6677, 20-3571, 20-3569, 18-6873, 20-7230, 19-1703, 21-109, 20-7232, 21-321, 18-3031, 18-3044, 18-6874, 18-6872, 18-6871, 19-1692, 19-1695, 19-1696, 20-843 and 20-6949).
Numerous studies have documented sub-lethal effects of rodenticide exposure in wildlife including lethargy, shortness of breath, anorexia, bloody diarrhea, changes in behavior, potential heart damage, and tenderness of the joints.[10] Clinical signs of sub-lethal exposure that often lead to death are also well known and include clotting, biochemical (including glucose and liver function markers) and physiological abnormalities, decreased body weight, and increased liver, heart, and/or kidney size[11]. Thus, it is reasonable to assume that rodenticides would - at very least - be noted as a contributing factor where symptoms and/or circumstances support such an inference. Yet this is not the case for B.C.’s wildlife. As a result, the presence of these products is never truly measured and their impacts are largely ignored.
Concerns raised by the necropsy reports themselves are further compounded by an apparent lack of avian mortality data collected in B.C.
The raptors represented by the necropsies discussed above only include those that were successfully submitted to and documented by the Wildlife Health Lab. These birds (300) merely scratch the surface with respect to birds found dead in B.C. during this time frame as most birds are never reported, thrown away, taxidermied or collected by local museums.[12] Additionally, wildlife rehabilitation organizations have reported “freezers full of birds'' intended for submission to the Wildlife Health Lab and backlogged. This is consistent with recent statements made by Helen Schwantje[13] on a conference call convened January 15, 2021 to discuss the “roles and responsibilities for all to understand what the status of various projects and processes are,” and the challenges of fulfilling the FOI request related to these reports:
“Sometimes we get shipments from rehabbers - we sort through and decide what we are going to do with them. So if there’s an owl we will send it over to Sandi for her research study with John, but many of those birds just get sent to the dump.”
“Rehabbers from the lower mainland...they get large amounts….”
“Really, we probably miss a lot of data through the rehabbers.”[14]
Our findings and analyses are not intended to make accusations. We recognize that those directly involved are doing the best they can with what they have. We are also in no way suggesting that additional resources or funding be directed toward raptor necropsies. Rather, by banning rodenticides there will be a natural decline in wildlife deaths and therefore fewer necropsies needed. The data we have is only the tip of the iceberg and is certainly enough to justify a provincial ban of these harmful products. It’s time for action. We are calling on B.C. to do the right thing and be the first Province in Canada to ban rodenticides.
Lindsey Zehel, Esq., LL.M.
Executive Director | Defend Them All Foundation
Portland, Oregon, United States
Deanna Pfeifer
Campaign Director | Rodenticide Free BC
Saanich, British Columbia, Canada
Marie Turcott
Defend Them All Foundation
Vancouver, British Columbia, Canada
[1] Shirley Woods, email message to Deanna Pfeifer confirming that the Provincial Health Services Authority does not collect specific data related to secondary rat poisoning (June 2, 2021).
[2] For example see Reports 17-5691, 17-6337, 18-120, 17-5694, 19-7935, 20-6664, 20-7237, 21-42, 21-45 , 21-194, 17-6337, 18-1505, 18-1520, 18-1533, 18-3025, 18-3032, 20-1589, 20-1585, 20-1584, 19-1677, 20-117, 20-1433, 20-2485, 20-7456, 20-7448.
[3] For example see Report 19 - 1703.
[4] For example see Report 19 - 1703, 21-109, 19-429.
[5] Anticoagulants can cause spontaneous liver rupture. See: Clementi, Marco, et al. "Spontaneous liver rupture associated with anticoagulant therapy A case report." Annali italiani di chirurgia 6 (2017) <https://pubmed.ncbi.nlm.nih.gov/28630388/>.
[6] Ibid.
[7] John Elliot, email message to Deanna Pfeifer (January 6, 2021).
[8] Laurie Wilson is a Migratory Bird Population Biologist with the Canadian Wildlife Service, Environment and Climate Change Canada, and the Pacific Wildlife Service Centre.
[10] Cox, P. and Smith, R.H. (1992). Rodenticide ecotoxicology: pre-lethal effects of anticoagulants on rat behavior,” Proc. Vertebr. Pest Conf, 15:165-170; Housenger, J.& Meléndez, J. (2012). Brodifacoum Analysis Risks of Brodifacoum Use to the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus), and the Federally Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris), and San Joaquin Kit Fox (Vulpes macrotis mutica) (PDF); Littin, K. E., C. E. O’Connor, C.E. and Eason, C.T. (2000). Comparative Effects of Brodifacoum on Rats and Possums, New Zealand Plant Protection Society (PDF); Munday, J. S., & Thompson, L.J. (2003). Brodifacoum Toxicosis in Two Neonatal Puppies, Vet Pathol (PDF); National Pesticide Information Center (2016). Rodenticides:Topic Fact Sheet (http://npic.orst.edu/factsheets/rodenticides.html).
[11] Naz, S., Rana, S. A., Javed, M., & Khalil-ul-Rehman (2011). Toxicological Effects of Brodifacoum
and Food Energy Inhibitor on Some Physiological Parameters in House Rats (Rattus rattus),
Pakistan Veterinary Journal (PDF); Daniels, D., DVM (2013). DPR 2013 Memorandum: Second Generation Anticoagulant Rodenticide Assessment. Riley S.P.D. et al., 2007. Anticoagulant Exposure and Notoedric Mange in Bobcats and Mountain Lions in Urban Southern California. J. Wildlife Management 71(6) 1874–1884.
[12] For example, Raptors collected by the Royal BC Museum 2017 - 2020 report.
[13] At the time these statements were made, Helen Schwantje was a lead Wildlife Veterinarian with the Forests, Lands, Natural Resource Operations and Rural Development (FLNRO)’s Wildlife Health Program. Helen has since stepped down from her position.
[14] Helen Schwantje, telephone conference organized by the Ministry of FLNRO, January 7, 2021(Recording available by request at dgpfeifer67@gmail.com)