A detailed necropsy performed on Charlie the chimp showed that the Oregon Zoo's revered resident died as a result of an infarction, a clot in his heart that caused an irregular heart rhythm.
"It would cause a very acute sort of death, it happens in people sometimes," senior veterinarian Mitch Finnegan said.
Charlie died Sept. 17 at age 39, considered late middle-age for a chimp. A zoo volunteer said Charlie, who had been energized all day and appeared to be in good health, rushed into the chimp exhibit's indoor space, bristled at visitors through the glass in a customary dominance display, then collapsed.
The four female chimps who lived with Charlie for more than three decades gathered around, shrieking and preventing zoo staff from immediately reaching Charlie and attempting cardio pulmonary resuscitation. Chimpanzees are fiercely strong, wildly emotional and can cause grotesque injuries, so must be handled with care.
"We couldn't get to him because of the females," Finnegan said. "It was over 10 minutes, the females were hysterical. When I got there I could see he'd stopped breathing. I could see a pulse, then it stopped about a minute later."
A memorial service at the zoo five days later drew hundreds of people, and an on-line message site filled with more than 90 tributes from people all over the country.
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