Here we highlight Richard Shore’s paper which explains the relationship between the raptor food chain and presence of rodenticides in bird of prey livers. The paper states that secondary exposure of predators can arise from eating contaminated:
- rodents subject to control (typically rats and house mice)
- non-target small mammals (e.g. mice and voles) that encounter and feed on rodent-attractive baits
- non-rodent vertebrate and invertebrate prey that also incidentally encounter and eat baits.
The paper compares bird exposure, determined from liver residues of second generation anticoagulant rodenticides (SGARs) in red kites (which feed extensively on rats), barn owls, kestrels, and tawny owls (which feed widely on non-target small mammals), and sparrowhawks (which feed predominantly on small birds).
The paper found that the scale and magnitude of exposure was broadly consistent with prey preference, and that age could be important as older birds can accumulate residues with age.
Shore, R. F, Potter, E. D, Walker, L. A, Pereira, M. G, Chaplow, J. S, Jaffe, J. E, et al. (2018). The Relative Importance of Different Trophic Pathways for Secondary Exposure to Anticoagulant Rodenticides. Proceedings of the Vertebrate Pest Conference, 28. https://escholarship.org/uc/item/5gv7t7w1
The paper was a proceeding from the 2018 Vertebrate Pest Conference https://escholarship.org/uc/vertebrate_pest_conference