The Skywalker Gibbon couple wake up every morning and sing to each other, their voices echoing across the forest ceiling of their home. The primate’s endearing love song has helped scientists confirm what was previously a strong hunch: Myanmar has the largest population of endangered skywalker gibbons on Earth.

When Star Wars-loving scientists identified Skywalker Gibbons as a distinct species in 2017, fewer than 200 individuals were known, all in southwestern China. A study published today in International Journal of Primatology The first person to confirm a living Skywalker Gibbon was in Myanmar in the last century.

The study was led by the Karen C. Dryer Wildlife Health Center at the University of California, Davis, which facilitated the formation of the Myanmar Skywalker Gibbon Conservation Committee. A group led by Myanmar investigators and comprised of Myanmar non-governmental organizations was tasked with guiding these important discoveries in their country. Field expeditions were conducted by partner organizations, including the Nature Conservation Society Myanmar and Fauna and Flora International – Myanmar.

“We were able to genetically identify 44 new groups of skywalker gibbons in Myanmar,” said senior author Terra Smiley-Evans, research faculty with the One Health Institute at the UC Davis School of Veterinary Medicine. “This is a great resource and success story for Myanmar.”

The exact number of individuals is unknown, but Skywalkers have been identified in the areas previously occupied by Eastern Holock Gibbons. Population estimates from 2013 suggested there could be as many as 65,000 gibbons in the area where Skywalkers are now identified, making it the largest possible population of Skywalker gibbons in one place.

Scientists suspect that the actual number today is lower given Myanmar’s ongoing poaching, limited protected areas and political unrest.

Love songs and chewed plants

Like their Jedi namesake, Skywalker gibbons cannot swim, so rivers define the boundaries of their species. This led scientists to think that the Skywalkers may have spread between two rivers in Myanmar in the west and the other in the east, but their theory remained unconfirmed until this study.

Security concerns related to civil and ethnic unrest, on top of a global pandemic, have limited primate surveys by foreign scientists in particular in Myanmar. Smiley Evans said the study was made possible by the efforts of the field research team in Myanmar.

Between December 2021 and March 2023, the field team in Myanmar set up audio monitoring systems, listening to Skywalker Gibbons’ love songs every morning, recording his solos and duets, their start and end times.

Using a non-invasive DNA sampling technique developed by Smiley-Evans, they then collected chewed plants and fruit from the gibbons. Genetic analysis of these specimens confirmed the species.

The team examined the images for features that distinguish the Skywalker holoc gibbon from other holoc species. These include thin eyebrows, a black or brown beard instead of white, and incomplete white circles on the face in women.

They also conducted threat assessment surveys in 12 villages to gather local information about gibbons and the threats they face.

“Biologists didn’t believe that skywalker gibbons could live in the small remnants of southern Shan State before we started this project,” said P Phyo Aung, executive director of the Nature Conservation Society Myanmar. “I am happy with the members of our field team who have done an excellent job in a very short time, building the confidence of the community for further conservation measures. This area is a degraded forest. For Myanmar and China, it is Really important to consider expanding conservation practices. For Skywalker Gibbon in this new geographic area.”

Red List Guidance

The findings will help guide the International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species.

While the findings increase skywalker gibbons population estimates, ongoing habitat loss, degradation and human conflict in Myanmar continue to threaten the species, most of which live outside protected areas.

For these reasons, the authors recommend that the species retain its endangered status on the IUCN Red List and that its habitat in Myanmar be considered for protected area status.

“We found skywalker gibbons in two regions of Myanmar: Kachin State and as far south as Shan State, in degraded forests and at much lower elevations than we expected, which shows us that they are highly adaptable,” Evans said. ” “There needs to be a safe area system that focuses on them.”

The study was a team effort with co-authors from University College London, Zoological Society of London, German Primate Centre, Livestock Breeding and Veterinary Department Myanmar, Myanmar Timber Enterprise, California National Primate Research Centre, Sun Yat-sen University and IUCN. Species Survival Commission (SSC) Primate Specialist Group Section on Small Apes.

The study was funded by the Arx Foundation, the IUCN SSC Primate Specialist Group Section on Small Apes, the National Science Foundation and the International Center for Integrated Mountain Development.