Silent killers? The widespread exposure of predatory nocturnal birds to anticoagulant rodenticides

• DOI: 10.1016/j.scitotenv.2023.166293
• Publication Date: 2023-08-14T05:45:47Z
• Authors: Raylene Cooke; Pam Whiteley; Clare Death; Michael A. Weston; Nicholas Carter; Kieran Scammell; Kaori Yokochi; Hao Nguyen; John G. White
• Keywords: Tyto; Barn-owl; Accipitridae

Anticoagulant rodenticides (ARs) influence predator populations and threaten the stability of ecosystems. Understanding prevalence impact in predators is crucial to inform conservation planning policy. We collected dead birds four nocturnal predatory species across differing landscapes: forests, agricultural, urban. Liver samples were analysed for eight ARs: three First Generation ARs (FGARs) five SGARs (Second ARs). investigated interspecific differences liver concentrations whether landscape composition influenced this. FGARs rarely detected, except pindone at low powerful owls Ninox strenua. SGARs, however, detected every 92 % analysed. Concentrations levels where potential toxicological or lethal impacts would have occurred 33 owls, 68 tawny frogmouths Podargus strigoides, 42 southern boobooks N. bookbook 80 barn Tyto javanica. When multiple likelihood potentially increased. There was no association between SGAR exposure, presence suggesting rodenticide poisoning ubiquitous all landscapes sampled. This widespread human-driven contamination wildlife a major threat health. Given high these types, we support formal consideration as threatening process. Furthermore, given that do not primarily eat rodents (tawny frogmouths, owls) comparable rodent (southern boobook, eastern owl), it appears there broader food-web than anticipated. provide evidence pose survival avian populations. functional importance ecosystems, combined with animal welfare chemicals, propose governments should regulate use SGARs.