Probabilistic risk assessment for snails, slugs, and endangered honeycreepers in diphacinone rodenticide baited areas on Hawaii, USA

Authors

  • John J. Johnston,

    Corresponding author
    1. U.S. Department of Agriculture (USDA)/Animal and Plant Health Inspection Service (APHIS)/WS/National Wildlife Research Center 4101 LaPorte Avenue, Fort Collins, Colorado 80521
    • U.S. Department of Agriculture (USDA)/Animal and Plant Health Inspection Service (APHIS)/WS/National Wildlife Research Center 4101 LaPorte Avenue, Fort Collins, Colorado 80521
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  • William C. Pitt,

    1. USDA/APHIS/WS/National Wildlife Research Center, Hilo Hawaii Field Station, P.O. Box 10880, Hilo, Hawaii 96721
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  • Robert T. Sugihara,

    1. USDA/APHIS/WS/National Wildlife Research Center, Hilo Hawaii Field Station, P.O. Box 10880, Hilo, Hawaii 96721
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  • John D. Eisemann,

    1. U.S. Department of Agriculture (USDA)/Animal and Plant Health Inspection Service (APHIS)/WS/National Wildlife Research Center 4101 LaPorte Avenue, Fort Collins, Colorado 80521
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  • Thomas M. Primus,

    1. U.S. Department of Agriculture (USDA)/Animal and Plant Health Inspection Service (APHIS)/WS/National Wildlife Research Center 4101 LaPorte Avenue, Fort Collins, Colorado 80521
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  • Melvin J Holmes,

    1. Department for Environment, Food, and Rural Affairs/Central Science Laboratory, Sand Hutton, York, Y041 1LZ United Kingdom
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  • Joe Crocker,

    1. Department for Environment, Food, and Rural Affairs/Central Science Laboratory, Sand Hutton, York, Y041 1LZ United Kingdom
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  • Andy Hart

    1. Department for Environment, Food, and Rural Affairs/Central Science Laboratory, Sand Hutton, York, Y041 1LZ United Kingdom
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Abstract

Three probabilistic models were developed for characterizing the risk of mortality and subacute coagulopathy to Poouli, an endangered nontarget avian species, in broadcast diphacinone-baited areas on Hawaii, USA. For single-day exposure, the risk of Poouli mortality approaches 0. For 5-d exposure, the mean probability of mortality increased to 3% for adult and 8% for juvenile Poouli populations. For Poouli that consume snails containing diphacinone residues for 14 d, the model predicted increased levels of coagulopathy for 0.42 and 11% of adult and juvenile Poouli populations, respectively. Worst-case deterministic risk characterizations predicted acceptable levels of risk for nonthreatened or endangered species such as northern bobwhite quail and mallards. Also, no acute toxicity was noted for snails and slugs that feed on diphacinone baits.

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