Anticoagulant rodenticides in birds of prey in Massachusetts, USA, 2012-2015

Recent restrictions on second-generation anticoagulant rodenticides (SGARs) in the United States prohibit the sale of SGARs to general consumers while allowing SGAR use by pest management professionals (PMPs). These... [ view full abstract ]

Recent restrictions on second-generation anticoagulant rodenticides (SGARs) in the United States prohibit the sale of SGARs to general consumers while allowing SGAR use by pest management professionals (PMPs). These restrictions were implemented in part to protect wildlife species from SGAR poisoning, which has been documented to result in mortalities in multiple species worldwide. The objective of this study was to investigate exposure to and toxicosis from ARs among four species of birds of prey admitted to a wildlife clinic in Massachusetts, USA, from 2012-2015. Liver tissue from 82 birds was analyzed; 95 % were positive for SGARs. Of the positive birds, 67 % contained residues of two or more SGARs. The cause of death was diagnosed as AR toxicosis in 18 % of birds. Of the birds that died from AR toxicosis, 79 % had residues of more than one AR. These data will be compared to previously published research in these same species in the same geographic location prior to restrictions on the sale of SGARs, 2006-2010. In addition, information from pesticide use reports (PURs) filed by PMPs with the Massachusetts Department of Agricultural Resources will be presented to illustrate patterns of use of different SGARs in the years 2008 and 2014. The data to be presented suggest that a regulatory approach that targets general consumer use of SGARs while allowing use by PMPs may not be adequate to protect nontarget species.