Scientific Studies

On this regularly-updated page we provide links to articles, presentations, and scientific and regulatory studies about the impacts of rodenticides on wildlife as well as domestic animals.

Anticoagulant rodenticides (ARs) continue to be widely used, affecting raptors and many other non-target animals. These products can cause both the prey and the animal that eats it to bleed to death internally. They can also cause minor injuries to be much more severe than they would be normally—for example, a poisoned animal might hemorrhage from a wound that would not ordinarily cause death. These terrible poisons also cause “sublethal” impacts, including suppression of an animal’s immune system, and affect overall health, behavior, and survivability. Cholecalciferol (a Vitamin D3 “overdose”) is another poison that can harm pets and wildlife.

 

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Short-term exposure of anticoagulant rodenticides leads to toxin accumulation from prey (Rattus losea) to predator (Elanus caeruleus) (Taiwan, 2022)

Anticoagulants pose threat to California condors (2022)

White-Tailed Eagles’ Exposure to Anticoagulant Rodenticides and Causes of Poisoning (Poland, 2022)

Unintended Harm: Rodenticides in Wildlife New Hampshire Wildlife Journal (2022)

Second generation anticoagulants in the blood of avian scavengers (2022)

Exposure of Urban Coyotes to Anticoagulant Rodenticides in Southern California: Sub-lethal Effects and Environmental Correlates (McKenzie et al.) 2022

High rates of anticoagulant exposure in California barred owls associated with wildland-urban interface (U.S. 2021)

Endangered Australian top predator frequently exposed to anticoagulant rodenticides (Australia, 2021)

Population decline in British kestrels linked to second generation anticoagulant rodenticides (2021)

Anticoagulant rodenticide exposure and toxicosis in bald and golden eagles in the United States (2021)

Anticoagulant-poisoned rats can carry more disease to humans (2021)

Linking landscape composition and biological factors with exposure levels of rodenticides and agrochemicals in avian apex predators (Germany, 2021)

Sensitivity of turtles to anticoagulant rodenticides: Risk assessment in the Ogasawara Islands (Japan, 2021)

Temporal Persistence of Bromadiolone in Decomposing Bodies of Common Kestrel (Falco tinnunculus) (Spain, 2020)

Accumulation of anticoagulant rodenticides in suburban wild boar: implications for human consumers (Spain, 2020)

Heavy rainfall releases anticoagulant rodenticides from baited sewer systems and outdoor surfaces into streams (Germany, 2020)

Toxic time bombs: Frequent detection of anticoagulant rodenticides in urban reptiles (Australia, 2020)

Frequent detection of anticoagulant rodenticides in raptors reflects government rodent control policy (Taiwan, 2019)

Brodifacoum toxicity in American kestrels with increased hazard upon further AR exposure (2019)

Survival and competing mortality risks: rodenticides are second-leading cause of death of mountain lions in greater Los Angeles area (2019)

Anticoagulant rodenticides in Strix owls indicate widespread exposure in west coast forests (2019)

Toxicity of anticoagulant rodenticides in the American Kestrel (2019)

Comprehensive review of worldwide poisoning by anticoagulant rodenticides in non-target animals (2019)

Land use change and rodenticide exposure trump climate change as the biggest stressors to endangered San Joaquin kit fox (2019)

Changes in detected anticoagulant rodenticides in Kentucky barn owls from 2012-2016 (2019)

Prevalence of anticoagulant rodenticides in feces of wild red foxes (Norway, 2019)

Wastewater-borne exposure of limnic fish to anticoagulant rodenticides (Germany, 2019)

Widespread anticoagulant poison exposure in predators in Cape Town (South Africa, 2019)

Widespread Anticoagulant Poison Exposure is Linked with Immune Dysregulation and Severe Notoedric Mange in Urban Bobcats (2018)

First evidence of anticoagulant rodenticides in fish in German freshwater aquatic systems (Germany, 2018)

Anticoagulant rodenticide exposure in Australian predatory bird increases with proximity to developed habitat (Australia, 2018)

Secondary anticoagulant rodenticide exposure in migrating juvenile red-tailed hawks (2018)

Impact of rodenticides on vole and predator populations (2018)

Exposure to rodenticides in Northern Spotted and Barred Owls on remote forest lands in northwestern California due to marijuana cultivation (2018)

Pilot study by the Ventura County Public Works Agency showing raptors to be more effective than rodenticides (2018)

Rodenticide exposure of threatened Northern Spotted Owl near marijuana growing operations (MGOs) (2018)

Second generation anticoagulant rodenticide residues in barn owls 2017 (UK, 2018)

Mortality of Western Burrowing Owls associated with brodifacoum exposure (2017)

Anticoagulant rodenticide exposure and toxicosis in four species of birds of prey (2017)

Urbanization and anticoagulant poisons promote immune dysfunction in bobcats (Serieys et al. 2017)

Accumulation of anticoagulant rodenticides in a non-target invertebrate, the slug (France, 2017)

Influence of Poisoned Prey on Foraging Behavior of Ferruginous Hawks (2017)

Characterizing Golden Eagle Risk to Lead and AR Exposure (2017)

Bioaccumulation of bromadiolone in earthworms (China, 2015)

Rodenticide Residues Deposited in Eggs of Tyto alba (2015)

Nontarget mortality of lesser short-tailed bats caused by diphacinone (New Zealand, 2015)

Anticoagulant Rodenticide Exposure and Toxicosis in Coyotes in the Denver Metropolitan Area (2015)

Patterns of Natural and Human-Caused Mortality Factors of a Rare Forest Carnivore, the Fisher (Pekania pennanti) in California (2015)

Anticoagulant rodenticide brodifacoum found in dead nestlings of Stewart Island robin (New Zealand, 2014)

Causes of mortality and unintentional poisoning in predatory and scavenging birds in California (2014)

Exposure pathways of anticoagulant rodenticides to nontarget wildlife (2013)

Silent Forests? Rodenticides on Illegal Marijuana Crops Harm Wildlife (2013 – further studies of impact on fishers)

Impacts of Rodenticide and Insecticide Toxicants from Marijuana Cultivation Sites on Fisher Survival Rates in the Sierra National Forest in California (2013)

Anticoagulant Rodenticides: Secondary Poisoning of Wildlife in California (2013 – includes sublethal impacts and alternatives)

Protecting Raptors From Rodenticides (2011, pub. 2013)

Suspected cholecalciferol rodenticide toxicosis in avian species at a zoological institution (2013)

Declining Little Eagles and increasing rabbit numbers near Canberra: is secondary poisoning by Pindone the problem? (Australia, 2012)

High Exposure Rates of Anticoagulant Rodenticides in Predatory Bird Species in Intensively Managed Landscapes (Denmark, 2012)

Killing rats is killing birds: “Persistent, bioaccumulative, and toxic” (PBT) (2012)

AR contamination in a rare carnivore [fisher (Martes pennanti)], four documented deaths and one altricial kit exposed in utero or via mother milk (2012)

Primary and secondary poisoning by anticoagulant rodenticides of non-target animals in Spain (2012)

Pathogen and rodenticide exposure in American badgers (Taxidea taxus) in California (2012)

Rodenticide Use on Black-tailed Prairie Dogs and Unintended Consequences to Non-target Wildlife (2012)

Acute toxicity, histopathology, and coagulopathy in American kestrels (Falco sparverius) following administration of the rodenticide diphacinone (2011)

Second generation anticoagulant rodenticides in predatory birds: Probabilistic characterisation of toxic liver concentrations and implications for predatory bird populations in Canada (abstract, 2011; click here for full PDF)

Intoxication of nontarget wildlife with rodenticides in northwestern Kansas (2011)

Assessing Some Potential Environmental Impacts from Agricultural Anticoagulant Uses (2010)

Comparative Toxicity of Diphacinone to Northern Bobwhite (Colinus virginianus) and American Kestrels (Falco sparverius) (2010)

“Super-Toxic” Rat Poison Kills Owls (2010)

Anticoagulant rodenticides in red-tailed hawks, Buteo jamaicensis, and great horned owls, Bubo virginianus, from New Jersey, USA, 2008-2010

Anticoagulant rodenticide exposure and toxicosis in four species of birds of prey presented to a wildlife clinic in Massachusetts, 2006-2010 (2011)

Accumulation of Anticoagulant Rodenticides in a Non-target Insectivore, the European hedgehog (Britain, 2009)

Acute poisoning of endangered red kites (Milvus milvus) in France (2008)

Exposure of non-target small mammals to rodenticides: short-term effects, recovery and implications for secondary poisoning (England, 2005)

Evidence of secondary poisoning of free-ranging riparian mustelids by anticoagulant rodenticides in France (2004)

Potential Risks of Nine Rodenticides to Birds and Nontarget Mammals: A Comparative Approach (U.S. Environmental Protection Agency, 2004)

Anticoagulant rodenticides in three owl species from Western Canada, 1988-2003

Toxicity and residues of brodifacoum in snails and earthworms (New Zealand, 2003)

Non-target and secondary poisoning risks associated with cholecalciferol (New Zealand, 2000)

Factors influencing estimation of pesticide related wildlife mortality (1999)

Poisoning of Wildlife with Anticoagulant Rodenticides in New York (1999)

Population Declines of Predatory Birds with Introduction of Klerat (brodifacoum) Rodenticide (Australia, 1997)

Secondary poisoning of foxes and buzzards (France, 1997)

A 1981 study of the toxicity of the anticoagulant brodifacoum to American kestrels (Falco sparverius) (1990)

Review of non-target hazards associated with rodenticide use in the USA (1988)

Potential Hazard to Eastern Screech-Owls and Other Raptors of Brodifacoum Bait Used for Vole Control in Orchards (1987)

Sublethal Impacts:

Summary Paper on Sublethal Impacts

Genome-wide expression reveals multiple systemic effects associated with detection of anticoagulant poisons in bobcats (2018)

Urbanization and anticoagulant poisons promote immune dysfunction in bobcats, increasing susceptibility to opportunistic infections and disease (2018)

Anticoagulant rodenticides in urban bobcats: exposure, risk factors and potential effects based on a 16-year study (2015)

Side effects of rodent control on non-target species: Rodenticides increase parasite and pathogen burdens in great bustards (2011)

Growth Performance of Nestling Barn Owls in Rat Baiting Area in Malaysia (2010)

Anticoagulant Exposure and Notoedric Mange in Bobcats and Mountain Lions in Urban Southern California (2007)

Evidence of secondary poisoning of free-ranging riparian mustelids by anticoagulant rodenticides in France (2004)

Domestic Animals:

Acute hemorrhage and death in calves following chlorophacinone exposure (2022)

Mechanisms of toxicity and residue considerations of rodenticide exposure in food animals (2022)

Many dogs have rat poison in their bodies (2016)

Anticoagulant rodenticides: deadly for pests, dangerous for pets (2002)