Li Jiahong still remembers the sound in March 1997 — a haunting call echoing through the Gaoligong Mountains in the rugged terrain of Yunnan province.

"I asked a fellow ranger, 'What animal makes that?'" he recalls. "He told me it was a 'black monkey' that never comes down from the trees." The stories captivated the then-young ranger at the Gaoligongshan National Nature Reserve.

For eight years, he pursued the source with his camera, always arriving too late. On May 16, 2005, he finally captured what he had been seeking — the first clear photograph of what would later be identified as a new species: the Skywalker hoolock gibbon.

The discovery marked only the second time a new gibbon species had been described anywhere in the world in the past century, and it remains the first — and still only — gibbon species ever named by a Chinese scientist.

"I only wanted to record it," Li said at a recent event marking the 20th anniversary of the photograph. "I never imagined it would attract so much attention."

The image opened doors for scientists like Fan Pengfei of Sun Yat-sen University, who led the research team that formally named the species in 2017. "When we first came to Gaoligong, the global scientific consensus was that these gibbons were Eastern hoolock gibbons," Fan said at the event. "But we noticed clear differences — the males, for instance, lacked white beards." Through a decade of research combining morphological analysis, DNA evidence, and dental studies, Fan's team confirmed they had discovered a new species.

Fan named it Hoolock tianxing — the Skywalker hoolock gibbon. "The Chinese name reflects how they move through the treetops as if walking in the sky," he said.

The discovery attracted global attention, with media coverage across more than 40 countries. But for Fan, the real work had just begun. "Their population is extremely small — fewer than 200 in China — and their habitat is fragmented," he noted. His team now focuses on conservation science: monitoring family groups, recording individual vocal fingerprints, and even attempting to help isolated gibbons find mates through recorded calls.

"Watching their behavior is fascinating," Fan added. "They're monogamous, raising children just like human families. The firstborn sleeps with mom; when a second arrives, the first moves to dad. After the kids leave, the couple sleeps together again — exactly like empty-nesters."

For Zhang Yunyi, a publicity official in Baoshan, the gibbon's story is about more than science — it's about identity. Speaking at the anniversary event, Zhang reflected on how far the species has come in public consciousness. "Twenty years ago, these gibbons were unknown even to many locals," she said."Now they've become world-renowned."

Zhang highlighted efforts to weave gibbon conservation into local culture and economy in Baoshan, a major coffee-growing region. A coffee plantation in the foothills now calls itself "Huke Manor", with "Huke" serving as an onomatopoeic rendering of the gibbon's call.

Lin Rutao, head of Baoshan's forestry and grassland bureau, said the manor represents just one part of a broader effort by local authorities to balance ecological protection with economic development.

In 2009, the city secured official recognition from the China Wildlife Conservation Association, which designated Baoshan as the "Home of the White-Browed Gibbon" — an acknowledgment of its early conservation work. White-browed gibbon is another name for the Skywalker hoolock gibbon.

The bureau subsequently elevated the gibbon to flagship species status, using its distinctive appearance to make biodiversity concepts more accessible to the public.

"We protect so that communities can share in the benefits," Lin said in an interview. "At Huke Manor, we sell 'gibbon coffee' — coffee brewed for the gibbon's call."

Contact the writers at lilei@chinadaily.com.cn