Evidence of Secondary Poisoning of Free-Ranging Riparian Mustelids by Anticoagulant Rodenticides in France: Implications for Conservation of European Mink (Mustela Lutreola)

Abstract

Because of the rapid decline of the endangered European mink (Mustela lutreola) populations in France, a national conservation program has been put into action, including research to understand the causes of decline. As part of this research, concentrations of eight anticoagulant rodenticides were examined in livers from 122 carcasses of four species of freeranging mustelids collected between 1990 and 2002 in southwestern France. Bromadiolone residue was found in all species and 9% of the sample (one of 31 European mink, three of 47 American mink [Mustela vison], five of 33 polecats [Mustela putorius], and two of 11 European otters [Lutra lutra]). Liver concentrations ranged from 0.6 g/g to 9.0 g/g. Chlorophacinone residue was found in two species and 4% of the sample (in four of the American mink and in one of the otters), with liver concentrations ranging from 3.4 g/g to 8.5 g/g. Two polecats and one American mink had lesions and liver residues indicating bromadiolone was directly responsible for their death. However, most of our study animals survived secondary poisoning until they were caught; this study certainly underestimates the extent of fatal exposure of mustelids to rodenticides. Moreover, anticoagulant poisoning could increase their vulnerability to other causes of death. The current status of the endangered European mink population is such that any additional risk factor for mortality is important, and it is thus urgent to monitor and reduce the extensive use of bromadiolone and chlorophacinone against field rodents in France.

Poisoning by Anticoagulant Rodenticides in Humans and Animals: Causes and Consequences

“…Wildlife expositions or intoxications to ARs have been reported around the world for many mammals such as minks [70], bobcats [71], stoats and weasels [72], foxes [73,74] and boars [67] and as well for many birds [75][76][77]. Exposition of ish was reported near an island where an eradication of rodent with brodifacoum was performed and the risk for human through the consumption appeared very low [78].…”

Development of an Ecofriendly Anticoagulant Rodenticide Based on the Stereochemistry of Difenacoum

“…Because of this increased persistence in animal tissues, especially in liver (Langford et al, 2013), the use of SGARs is associated with an increased risk of secondary poisoning for predators and scavengers feeding on contaminated rodents. Evidence of secondary poisoning was confirmed in predatory bird species such as barn owl (Tyto alba), buzzard (B. buteo), kestrel (Falco tinnunculus), Red kyte (Milvus milvus), and tawny owl (Strix aluco) (Christensen et al, 2012 ;Hughes et al, 2013 ;Geduhn et al, 2015), in predatory mammals such as red foxes (Vulpes vulpes) (Sage et al, 2010), European mink (Mustela lutreola) (Fournier-Chambrillon et al, 2004), weasels (Mustela nivalis) (Elmeros et al, 2011). Therefore, ARs were identified by the European Union as candidates for future comparative risk assessment and substitution in view of their unacceptable risk of secondary poisoning for wildlife.…”

Landscape characteristics affect animal control by urban residents

“…In Europe, Brakes and Smith (2005) reported small mammals consuming bait during routine rat control, which severely affected small mammal populations. Residues have been reported in avian and terrestrial predators in Europe (Shore et al 2003, Fournier-Chambrillon et al 2004, Walker et al 2008 and Asia (Duckett 1984). In Canada, use of brodificoum for rat eradication presented obvious exposure to avian scavengers (Howald et al 1999, Albert et al 2010.…”