What could be Asia’s longest-missing bird just came out of hiding. For the first time in 170 years, researchers reported last week that a black and brown babbler was found in Indonesia. The discovery of the muted black, gray and maroon bird solves what one authoritative bird watcher describes as “one of the great mysteries of Indonesian ornithology”.

“When we actually received confirmation of identification, I prayed a little and bowed to celebrate,” said Panji Gusti Akbar, ornithologist and lead author of the paper describing the new species. “I felt excitement, disbelief, and good luck.”

Ornithologists first described black-and-brown babblers around 1850 after collecting the only known specimen of the species. The specimen was initially mistakenly labeled as originating from the island of Java and not from Borneo, which hampered early attempts to find additional black-and-brown babblers. But even after ornithologists cleared up the geographic mix-up, no one managed to find the bird. It didn’t help that traditionally few bird watchers and ornithologists ventured to the Indonesian side of Borneo.

In 2016 this began to change with the establishment of BW Galeatus, a bird watching group in Borneo, Indonesia. BW Galeatus members have reached out to the local population to educate them about the bird diversity in their provinces. Two of these local men, Muhammad Suranto and Muhammad Rizky Fauzan, were curious about the identity of a black-and-brown bird that they sometimes saw darting around on their journeys into the forest in South Kalimantan, one of the Indonesian provinces on Borneo. Last October, Mr. Suranto and Mr. Fauzan managed to catch one of the birds and text photos for Joko Said Trisiyanto, a member of BW Galeatus.

“I was confused when we got the pictures because it looked a bit like Horsfield’s chatter, but it didn’t really match,” said Mr. Trisiyanto. The photos were more like an illustration of a black and brown babbler – a bird listed in Mr. Trisiyanto’s guidebook as possibly extinct.

Confused, Mr. Trisiyanto passed the pictures on to Mr. Akbar. He was shocked.

“I was pacing my house just trying to contain my excitement,” he said.

Mr. Akbar sent the photos to other experts, including Ding Li Yong, a conservationist at BirdLife International in Singapore and the regional liaison for the Oriental Bird Club, a UK-based bird group. Dr. At first Yong thought someone was playing a prank – he was looking at a photoshopped picture, perhaps of an ant bird from Ecuador.

“It took me a while to get into this thing,” said Dr. Yong. When he found the photos were legitimate, he said, “I had a tear in my eye.”

“This is a really big deal for Indonesian ornithology – as shocking as the rediscovery of the passenger pigeon or the Carolina parakeet,” said Dr. Yong and named two extinct bird species. “But that’s closer to home, a bird from the part of the world I live in.”

After the bird’s identity was confirmed, Mr. Trisiyanto persuaded Mr. Suranto and Mr. Fauzan to release the captured animal back into the forest. He and Mr. Akbar hope to use the black and brown babbler discovery to build greater local interest in nature and bring tourist dollars to the area. They also plan to train Mr. Suranto and Mr. Fauzan to be bird watchers.

“Bird watchers from around the world have already started contacting me about the opportunity to visit and see this bird,” said Akbar, a member of Birdpacker, a bird watching and leadership group based in East Java.

As soon as the travel restrictions for Covid-19 are lifted, he and his colleagues are planning an expedition to investigate the black and brown babbler. “Basically we have no knowledge of this bird,” said Mr. Akbar.

However, they already fill in some gaps. For example, the 170 year old specimen has bright yellow glass eyes and legs that have faded light brown. Based on photos of the living bird, the researchers now know that the species has deep scarlet eyes and gray legs.

“This is the first time we have seen this bird alive in all of its natural splendor,” said Dr. Yong. “Borneo is an island full of surprises and there is still a lot to discover and learn.”