This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Mice and rats can spread dangerous viruses and bacteria, trigger asthma attacks and damage property with their constant gnawing. So when rodents get indoors, most people take action to help keep their home safe.
Some rodent poisons can have unintended effects on wildlife. Anticoagulant rodenticides—which prevent blood from clotting and cause rodents to die from internal bleeding—are a commonly used type of rodent poison. Unfortunately, anticoagulant rodenticides can be transferred to predators such as hawks and owls when these birds consume poisoned prey animals.
This exposure through their prey can result in the death of the predators. "No one wants rats or mice in their home," said Maureen Murray, V03, the Shalin Liu Professor of Wildlife Medicine at Cummings School of Veterinary Medicine at Tufts University. "While I am often asked if some poisons are safer for wildlife, the words 'safe' and 'poison' inherently do not go together." Murray, a wildlife veterinarian and director of Tufts Wildlife Clinic, has spent two decades studying the effects of rodenticides on wildlife.
In a 2020 publication, she found that 100% of red-tailed hawks included in the study were positive for exposure to anticoagulant rodenticides. The study, published in Environmental Toxicology and Chemistry, also found that 91% of the birds tested positive for two or more different anticoagulant rodenticides. In a 2023 study that analyzed four species of birds of prey for rodenticides, she found that 96% of the tested birds were positive for anticoagulant rodenticides.
Published in Environmental Pollution, the study also found that 81% of the birds overall were exposed to two to four different anticoagulant rodenticides. The danger comes from how these poisons work. Rodents often survive for several days after eating bait—and may continue feeding during that time.
As a result, their bodies can contain enough poison to kill the hawks, owls, foxes, coyotes and other predators that eat them. Because these chemicals accumulate in the liver, predators that repeatedly consume poisoned prey can build up lethal amounts over time, even if each individual meal contains only a small dose. The 2023 study was also the first to document evidence of exposure to a different type of rodent poison in birds of prey: bromethalin, a neurotoxic rodenticide that has been used more frequently in recent years as an alternative to anticoagulant rodenticides.
Extract — continue reading at the source.
