SUFFOLK CLOSEUP: Rat Poison Impacts All Wild Life Even Eagles

SUFFOLK CLOSEUP

By Karl Grossman

 This spring, wildlife biologist Mike Bottini was working on his ongoing survey of the presence of river otters on Long Island when at Montauk County Park beneath an eagle’s nest he came upon a dead adult bald eagle. 

“The carcass was perfectly intact with no scavenger marks,” relates Bottini. It had likely
“perished earlier that day.” 

He sent it for examination by the New York State Department of Environmental Conservation’s Wildlife Pathology Unit. Recently, he received the necropsy report. (Necropsy is a post-mortem examination of an animal’s body to determine the cause of death, similar to an autopsy performed on humans.)

The report, he noted, “found extensive hemorrhaging and high levels of brodifacoum, an anticoagulant [blood thinning] rodenticide. Brodifacoum is one of several ‘second generation’ anticoagulant rodenticides.”

In other words, the eagle had died from a pesticide used to kill rodents and which is commonly referred to as “rat poison.” However, squirrels, woodchucks, chipmunks and other animals also will die as a result of consuming a rodenticide. 

A main characteristic of a “second generation” rodenticide, explains Bottini, is that the poisoned animal does “not die immediately. The poison may take several days to kill the animal. During that time the animal is not behaving normally and is an easy target for rodent predators: owls, hawks, foxes and eagles.” 

“I’ve since learned that the attempt by the EPA to regulate the use of these rodenticides was opposed by the manufacturers of these poisons, and the resulting regulations imposed were a compromise that is ineffective in addressing the problem,” Bottini wrote me.

The situation goes well beyond that dead eagle in Montauk.

Mike sent me a variety of scientific reports, and I Googled others.

Last week, I began a course that I have been teaching for decades at the State University of New York at Old Westbury, Environmental Journalism. I start it by having the students read and write essays on Silent Spring by Rachel Carson. The disclosures in that landmark 1962 book resulted in a ban on the use of DDT and the establishment of the Environmental Protection Agency, the EPA. 

However, there are still many pesticides and other chemical poisons still in use that have deadly impacts on not only what they are designed to kill but, like DDT, broad consequences.

In doing research that resulted in Silent Spring, Carson made use of testimony in a lawsuit brought against the Suffolk County Mosquito Control Commission for its wanton spraying of DDT here. DDT almost made extinct Long Island’s signature bird, the osprey, by causing the shells of its eggs to be so thin that when an osprey sat on them they shattered. 

Clearly, rodenticides are also having broad impacts far and wide.

For example, research at Tufts University in Massachusetts has found that “100% of tested red-tailed hawks at Tufts Wildlife Clinic to be exposed to anticoagulant rodenticides.” Tufts reported: “Maureen Murray, director of Tufts Wildlife Center and clinical associate professor at Cummings School of Veterinary Medicine has been studying exposure in birds of prey for over a decade. Exposure of rodenticides occur when people use these chemicals to kill unwanted pests. Mice or rats, or possibly other animals, eat the poison, and then the birds eat the poisoned prey.”

Or as a study reported in the journal Frontiers in Ecology and Evolution, rodenticide exposure in fishers is extensive “across the northeastern United States,” and not only are these weasel-like mammals affected but “studies in parts of Europe, New Zealand and North Aerica indicate uptake of anticoagulant rodenticides by predatory mammals to be widespread and common.”

Research at the University of California Davis looked at dead fishers, northern spotted owls and also bobcats with anticoagulant rodenticides in their systems. A report on this begins: “Rodents often get a bad rap—and for good reason. They leave droppings in our homes and attics that may spread disease. They chew through electrical wire….They raid tomato gardens and fruit trees. That’s why people use rodenticide to poison them. The problem is that anticoagulant rodenticides have a ripple effect in the environment. Not only do they kill mice and rats, they also result in death or serious disease of…other wildlife that feed on the rodents or come into direct contact with the poison.”

As a study in Environmental Chemistry Letters reported, rodenticides are also having an impact “in the aquatic environment”—on fish.  And “anticoagulants accumulating in aquatic wildlife are likely to be transferred in the food chain, causing potentially serious consequences for the health of wildlife and humans alike.”

As to what to do about mice and rats, Bottini, a resident of Springs in East Hampton and a wildlife biologist at Islip-based Seatuck Environmental Association, suggests mouse traps.

“In my experience, the most effective non-toxic method of reducing mouse and rat numbers is the old-fashioned trap,” says Mike.

Karl Grossman is a veteran investigative reporter and columnist, the winner of numerous awards for his work and a member of the L.I. Journalism Hall of Fame. He is a professor of journalism at SUNY at Old Westbury and the author of six books.