Challenges in the interpretation of anticoagulant rodenticide residues and toxicity in predatory and scavenging birds

• Published in: Pest management science 2021-02, Vol.77 (2), p.604-610
• Main Authors: Rattner, Barnett A, Harvey, Joel J
• Format: Article
• Language: English
• Subjects: Animals; Anticoagulants; Anticoagulants - toxicity; Birds; Exposure; Hemorrhage; Intoxication; Liver; Natural resource management; Natural resources; Nutrition; potency; Predators; Predatory Behavior; Prey; Public domain; Regulators; Residues; Rodenticides; Rodenticides - toxicity; Scavenging; Toxicity; toxicokinetics; toxicosis; Vitamin K; vitamin K epoxide reductase; Wildlife; Wildlife management
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.6137

Anticoagulant rodenticides (ARs) are part of the near billion‐dollar rodenticide industry. Numerous studies have documented the presence of ARs in nontarget wildlife, with evidence of repeated exposure to second‐generation ARs. While birds are generally less sensitive to ARs than target rodent species, in some locations predatory and scavenging birds are exposed by consumption of such poisoned prey and, depending on dose and frequency of exposure, exhibit effects of intoxication that can result in death. Evidence of hemorrhage in conjunction with summed hepatic AR residues >0.1–0.2 mg kg−1 liver wet weight are often used as criteria to diagnose ARs as the likely cause of death. In this review focusing on birds of prey and scavengers, we discuss AR potency, coagulopathy, toxicokinetics and long‐lasting effects of residues, and the role of nutrition and vitamin K status on toxicity, and identify some research needs. A more complete understanding of the factors affecting AR toxicity in nontarget wildlife could enable regulators and natural resource managers to better predict and even mitigate risk. Published 2020. This article is a U.S. Government work and is in the public domain in the USA Anticoagulant rodenticide potency, residues, toxicokinetics, and role of nutrition are discussed in relation to toxicosis in nontarget raptorial birds, and critical research needs are identified that might enhance ecological risk assessments.