According to zoo officials, based on necropsy findings, the bear died from lymphoma, a form of cancer, as well as old age.
Additional results will be available in six weeks, the zoo stated.
“Given that Zero was one of the nine oldest male polar bears in Association of Zoos and Aquariums (AZA)-accredited institutions, a cause of death correlated with advanced age was high on the differential list,” Dr. Jeff Wyatt, the zoo’s director of animal health and conservation, said.
Zero had been relocated to Rochester from the Milwaukee County Zoo in 1989, in order to mate with a female polar bear named Aurora.
“We are dedicated to conserving this threatened species, through educational programs, fundraising and research,” Pamela Reed Sanchez, executive director of the Zoo Society, stated. “Our message is that individuals can make a difference for polar bears, just as Zero touched the lives of hundreds of thousands of visitors over the years.”
Sanchez said officials are currently determining plans to bring another polar bear to the zoo.