Cities are at war with rats. Flaco the owl and other animals pay the price.

• Flaco, the loose Central Park Zoo owl, died with lethal levels of rat poison  in his system.
• Rodenticides used in cities like New York also poison other wildlife, especially birds of prey.
• The problem could become worse as cities ramp up their efforts to combat rats.

Flaco, the owl who escaped from the Central Park Zoo last year and transitioned to life as a free New Yorker, had lethal levels of rat poison in his system when he died last month — a problem that impacts non-famous birds of prey and other animals as well.