The Red-tailed Hawks of Central Park and Secondary Poisonings: Part I

By Marcia Anderson

Two of the young red-tailed hawk hatched from a nesting couple in Central Park, New York City, have recently been diagnosed with cases of poisoning from rodent baited traps set out in neighboring properties. The two eyasses, were captured, diagnosed and treated for secondary poisoning.

What is primary versus secondary poisoning? Primary poisoning refers to poisoning resulting from eating a bait. Secondary poisoning occurs when eating another animal that has been poisoned, such as a bird eating a rat containing residues of a rodenticide.

Red-talked hawk nest (image c/o D. Bruce Yolton)

People often forget to think about the fact that once the animal they have targeted has eaten poison, that animal itself now becomes poison for any other animals which may eat it. In other words, if your dog or cat eats a poisoned mouse they too will now have ingested the poison as secondary poisoning. Each year countless pets, wildlife, even beautiful eagles and hawks die from secondary poisoning. You do not want to be responsible for the death of the wrong animal via poisoning.

The problem with poisoning rodents is that it doesn’t kill them fast enough. Poisoning produces a slow death for any animal which may ingest it. Anti-coagulants contain chemicals that limit blood clotting and can take up to 2 weeks to kill the animal. The rodents wander aimlessly for hours before dying… easy prey for a hungry wild mammal or raptor. Secondary poisoning is just as serious as primary poisoning; as the animal is too sick to hunt or fly, and will often starve to death (secondary victims are often the young, who once back at the den or nest will become disoriented, lethargic, and will starve to death or fall prey to other predators). These two young hawks were very lucky, as they and their parents are very high profile residents of Central Park and concerned citizens noticed the changes in their behavior and help was timely provided.

The question is: Which birds and mammals are at risk? Continue reading

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.