Zura, the San Francisco Zoo's beloved Western lowland gorilla — who was the granddaughter of the first-ever gorilla born in captivity — passed away before the weekend at almost 40 years old.

Western lowland gorillas are one of our closest living relatives, sharing about 98% of our own genetic makeup. But the bushmeat trade, rampant deforestation, and human-contracted illnesses have decimated their populations in central and West Africa; only about 100,000 remain in the world — a 60% population decline from their numbers 25 years ago.

And Zura, the city zoo's much-loved female Western lowland gorilla, was one of only a handful of the primates ever successfully born and reared in captivity. But due to chronic digestive issues that recently worsened, SF Zoo officials announced she perished yesterday.

"It is with deep sadness that we announce the passing of Zura, 39-year-old female Western lowland gorilla," writes the local zoological facility in a tweet Friday. "She was a favorite for generations of families & animal care staff alike since her arrival in 1982. Her beautiful, distinctive face & sassy personality will truly be missed."

Zura came to San Francisco in 1982 from the Columbus Zoo, where her grandmother was Colo — she being regarded as the first gorilla born in captivity. At the zoo, she lived to 60 years old before dying of old age in 2017; most gorillas in the wild live between 35 and 40 years, but the easy access to food, water, and shelter (and medical attention) in captivity means they can live decades longer than possible in their natural habitats.

Zura, even into her old age, remained a "one-of-a-kind personality."

“Zura had a beautiful, distinctive face and a one-of-a-kind personality, and so many of our guests recognized her when they visited,” said CEO and Executive Director of San Francisco Zoological Society Tanya M. Peterson in a statement to KPIX. “As one of our older females, she lived among different generations of our gorilla troop, from the great silverback, ‘Bwana’ to our gentle, contemplative silverback, ‘OJ.’ She will be missed by all of us.”

Though she never mothered any offspring of her own, Zura was an "auntie"  to many of the group's young gorillas.

Her passing leaves the San Francisco Zoo's Jones Family Gorilla Preserve with a troop — which is the name given to a group of gorillas — that numbers four Western lowland gorillas, an adult male silverback and three adult females.

Currently, there are four recognized subspecies of gorillas — Western lowland gorillas (Gorilla gorilla gorilla), cross river gorillas (Gorilla gorilla diehli), Eastern lowland gorillas (Gorilla beringei graueri), and mountain gorillas (Gorilla beringei beringei) the subspecies Diane Fossey helped elevate to widespread notoriety — and each is threatened by human activity and could disappear this century without adequate conservation practices and policy changes.

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Image: Twitter via @sfzoo