Vietnam - October 29, 2024 [Credit: Nguyen Huy Cam] In an extraordinary feat of adaptation, the critically endangered Cat Ba langurs have developed the ability to drink salt water, a lifeline for survival in their isolated, resource-scarce environment. This unique capability, detailed in a study by the German Primate Center and Leipzig Zoo, showcases the langur’s resilience despite severe genetic challenges and habitat limitations. With fewer than 100 individuals remaining, the Cat Ba langur (Trachypithecus poliocephalus) faces high inbreeding and diminished genetic diversity. However, research published in Nature Communications reveals that critical genetic traits enabling them to withstand salt water and limited resources have endured. “Their adaptability makes the animals unique,” said geneticist and lead author Liye Zhang, emphasizing that this rare trait is likely a result of genetic shifts allowing for higher sodium tolerance. The Cat Ba langur is not only one of the world’s most endangered primates but a symbol of nature’s adaptability and the urgent need for protection. Once numbering in the hundreds, their population plummeted to just 40 by 2004 due to poaching and habitat loss. While ongoing conservation efforts have doubled the population to around 85, threats from habitat fragmentation, tourism, and inbreeding persist. The Cat Ba Langur Conservation Project, managed by Leipzig Zoo and local partners, has been instrumental in the species' recovery. However, as Leipzig Zoo Director Jörg Junhold warns, “It would be premature to call this highly endangered species saved.” Experts stress the importance of continued conservation measures, habitat expansion, and potentially reintroducing the langurs to other parts of the island to secure their future.