Anticoagulant rodenticides in urban bobcats expos

Authors: L E K Serieys T C Armenta J G Moriarty E E Boydston L M Lyren R H Poppenga K R Crooks R K Wayne S P D Riley

Publish Date: 2015/02/25

Volume: 24, Issue: 4, Pages: 844-862

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Abstract

Anticoagulant rodenticides ARs are increasingly recognized as a threat to nontarget wildlife High exposure to ARs has been documented globally in nontarget predatory species and linked to the high prevalence of an ectoparasitic disease notoedric mange In southern California mange associated with AR exposure has been the proximate cause of a bobcat Lynx rufus population decline We measured AR exposure in bobcats from two areas in southern California examining seasonal demographic and spatial risk factors across landscapes including natural and urbanized areas The longterm study included bobcats sampled over a 16year period 1997–2012 and a wide geographic area We sampled blood N = 206 and liver N = 172 to examine exposure ante and postmortem We detected high exposure prevalence 89  liver 39  blood and for individuals with paired liver and blood data N = 64 92  were exposed Moreover the animals with the most complete sampling were exposed most frequently to three or more compounds Toxicant exposure was associated with commercial residential and agricultural development Bobcats of both sexes and age classes were found to be at high risk of exposure and we documented fetal transfer of multiple ARs We found a strong association between certain levels of exposure ppm and between multiple AR exposure events and notoedric mange AR exposure was prevalent throughout both regions sampled and throughout the 16year time period in the longterm study ARs pose a substantial threat to bobcats and likely other mammalian and avian predators living at the urbanwildland interfaceFunding was provided by the National Science Foundation Graduate Research Fellowship Summerlee Foundation Santa Monica Bay Audubon Society National Science Foundation Ecology of Infectious Disease research program NSF EF0723676 University of California Los Angeles US Geological Survey Panthera Dan and Susan Gottlieb the G2 gallery Barry Rowan the California Mediterranean Research and Learning Center Julie Newsome and Joel and Kian Schulman We thank C Schoonmaker EC York J Sikich D Fraser C Reddell I Kelsey K Fragiacomo J Warner R Alonso R Mowry J Kraft J Purdum D Newell and B Nerhus for field assistance For veterinary support in OCSA we thank S Weldy and K Krause Thanks to UCLA ATS consulting and S Carver for help with data analysis We appreciate all support and editorial comments provided by P Jackson T Smith J LloydSmith and anonymous reviewers Any use of trade product or firm names is for descriptive purposes only and does not imply an endorsement by the US Government

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