Flaco, owl whose death shocked NYC, had evidence of bird herpes and rat poison

Flaco, the owl who endeared himself to New Yorkers in sightings around Manhattan, had underlying conditions consistent with urban wildlife when he died last month, zoo officials said.

Flaco was roughly 13 years old when he was found dead Feb. 23 in the courtyard of an apartment building in New York City’s Upper West Side, Central Park Zoo, his former home, said.

While a next-day necropsy found he died of “acute traumatic injury” after witnesses saw him strike the building, he also had significant underlying conditions, revealed in a Central Park Zoo statement Monday.

Completed postmortem testing found Flaco had severe pigeon herpesvirus from eating feral pigeons. There was also evidence of four anticoagulant rodenticides commonly used for rat control, which together composed another significant underlying condition, it said.

“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 zoo said.

Herpesvirus can be fatal in birds of prey like Flaco, where it caused tissue damage and organ inflammation, it said. 

Flaco flew for more than a year over Central Park and perimeter neighborhoods after he left his zoo habitat when a vandal breached his enclosure on Feb. 2, 2023.

The case remained under investigation, and no suspects have been arrested, the New York Police Department said last month.

Though some expected the wilds of New York might be hostile to a wild bird with a tony address, Flaco adapted his diet and habits to the concrete jungle.

Still, city life might have had an impact on his longevity.

“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,” the zoo said.