Central Park Zoo Releases Postmortem Testing Results for Flaco, the Eurasian Eagle Owl

New York, March 25, 2024 – The following statement was released today by Central Park Zoo:

Postmortem testing has been completed for Flaco, the Eurasian eagle owl that was found down in the courtyard of a Manhattan building a little over a year after his enclosure at the Central Park Zoo was vandalized on February 2, 2023. Onlookers reported that Flaco had flown into a building on the Upper West Side of Manhattan on February 23, 2024, and acute trauma was found at necropsy.

Bronx Zoo veterinary pathologists determined that in addition to the traumatic injuries, Flaco had two significant underlying conditions. He had a severe pigeon herpesvirus from eating feral pigeons that had become part of his diet, and exposure to four different anticoagulant rodenticides that are commonly used for rat control in New York City. These factors would have been debilitating and ultimately fatal, even without a traumatic injury, and may have predisposed him to flying into or falling from the building.

The identified herpesvirus can be carried by healthy pigeons but may cause fatal disease in birds of prey including owls infected by eating pigeons. This virus has been previously found in New York City pigeons and owls. In Flaco’s case, the viral infection caused severe tissue damage and inflammation in many organs, including the spleen, liver, gastrointestinal tract, bone marrow, and brain.

No other contributing factors were identified through the extensive testing that was performed.

Flaco’s severe illness and death are ultimately attributed to a combination of factors—infectious disease, toxin exposures, and traumatic injuries—that underscore the hazards faced by wild birds, especially in an urban setting.

Toxicology testing also revealed trace amounts of DDE, a breakdown product of the pesticide DDT, but the levels detected in Flaco were not clinically significant and did not contribute to his death. Although DDT has been banned in the United States since the early 1970s, it and its breakdown products are remarkably persistent in the environment, and this finding is reminder of the long legacy of DDT and its dire effects on wild bird populations.

(Flaco died on Feb. 23, 2024. You can read the full statement from Central Park Zoo upon his death HERE. And you can read our initial necropsy results released on Feb. 24, 2024, HERE.)

https://newsroom.wcs.org/News-Releases/articleType/ArticleView/articleId/22247/Central-Park-Zoo-Releases-Postmortem-Testing-Results-for-Flaco-the-Eurasian-Eagle-Owl.aspx