Though she beat the odds and lived a dramatically longer-than-average life, Chicago's Lincoln Park Zoo is mourning the death of a geriatric chimpanzee euthanized Wednesday at age 50.
Vicky, who lived in a behind-the-scenes group at the zoo's Regenstein Center for African Apes, was also the zoo's last chimp to have been born in the wild.
“These are very personal losses for everyone that worked with her," Steve Ross, director of the zoo's Lester E. Fisher Center for the Study and Conservation of Apes told The Huffington Post. "It’s a very personal relationship.”
Ross, who saw Vicky nearly every day for the past 14 years, added that when an animal's health fails, "it’s a difficult but right decision [to euthanize.] Ultimately, our goal is to help our great apes live healthy and thrive."
The average life expectancy for female chimpanzees like Vicky is just under 39 years, making her survival to 50 an exceptional feat -- one Ross credits to the zoo and advances in veterinary care.
At zoos around the nation, the population of wild-born chimpanzees like Vicky is growing smaller every day.
“There are still about 45 wild-born chimps living accredited zoos, which is about 17 percent of the accredited zoo population," Ross said. “Vicky came to Lincoln Park Zoo in 1971 and at that time, zoos and other places were still importing apes from the wild.”
That practice was ended in 1975 when the Convention on International Trade in Endangered Species of Wild Fauna and Flora Treaty was adopted with the goal of protecting endangered species worldwide.
Now that all great apes in zoos are born into captivity, the Chimpanzee Species Survival Plan (SSP) -- a program implemented in all accredited zoos that helps chimps and other endangered species -- protects the "demographic and genetic health of the population."
“The SSP, which is based at Lincoln Park Zoo, ensures things like inbreeding don’t happen at zoos and that breeding recommendations are made to reduce the loss of genetic diversity,” Ross explained.
During her time at Lincoln Park Zoo, Ross said Vicky played an important social role in her peer group since animals born in captivity often learn the most from their wild-born peers.
With just two chimpanzee groups at the zoo now, Ross said Vicky's loss will be felt by the apes, too.
“There’s a lot of exploratory behavior that happens after the loss, which seems to indicate they may be looking for that [missing] individual," Ross said. "But the chimps at Lincoln Park Zoo have amazingly good relationships with the researchers that work with them, so it’s nice they have social support from their caretakers as well.”
Ross added, “I’m happy that she had a very long and very healthy life."