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(105) Probabilistic modelling of risks to avian and mammalian predators and scavengers from rodenticide residues in their prey. Hart, Andy1, Shore, Richard2, McDonald, Robbie3, Cowan, David1, Harris, Stephen4, MacNicoll, Alan1, Garthwaite, Dave1, 1 2 3 4 ABSTRACT- In the UK some incidents involving the death of red kites have been attributed to secondary poisoning by anticoagulant rodenticides. Also, monitoring studies show that residues of rodenticides are present in a substantial proportion of barn owls, pole cats, stoats, weasels and foxes. These findings have led to concerns that current assessment procedures underestimate risks to avian and mammalian predators and scavengers from the approved use of rodenticides. We developed a probabilistic risk assessment model using behavioural, ecological and toxicological data for both predators and their prey. The model simulates the distributions of residues in prey animals and the consequent uptake and effects in predators. Many of the factors affecting exposure and effects vary between individuals, species and rodenticides. Most of these are poorly understood. We therefore modelled the risks using second-order Monte Carlo simulations to separate and quantify the influence of variability and lack of knowledge. This enabled us to identify the main determinants of risk. We discuss key areas of uncertainty where further research is needed. Key words: probabilistic, risk, model, rodenticide |
