Anticoagulant rodenticides in urban bobcats: exposure, risk factors and potential effects based on a 16-year study

Ecotoxicology
By: , and 

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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 long-term study included bobcats sampled over a 16-year period (1997–2012) and a wide geographic area. We sampled blood (N = 206) and liver (N = 172) to examine exposure ante- and post-mortem. 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 16-year time period in the long-term study. ARs pose a substantial threat to bobcats, and likely other mammalian and avian predators, living at the urban-wildland interface.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Anticoagulant rodenticides in urban bobcats: exposure, risk factors and potential effects based on a 16-year study
Series title Ecotoxicology
DOI 10.1007/s10646-015-1429-5
Volume 24
Issue 4
Year Published 2015
Language English
Publisher Springer
Contributing office(s) Western Ecological Research Center
Description 19 p.
First page 844
Last page 862
Online Only (Y/N) N
Additional Online Files (Y/N) N