Very interesting. A few years ago, Trachypithecus cristatus was split into several different species, resulting in some confusion when animals are labelled. The animals on this photo look like Trachypithecus germaini, a species that is very rare in zoos outside its native range.
The two differ in distribution and appearance:
- T. cristatus is native to Malaysia, Indonesia and Brunei. It appears all dark silvery grey (the very local race vigilans of Natuna Islands is more similar to T. germaini).
- T. germaini is native to Laos, Vietnam, Cambodia, Myanmar and Thailand. Overall it is a bit paler than T. cristatus, and it has distinctly light cheeks and throat.
Thanks for your information. I think I can distinguish between them if they have "typical" appearance. But some individuals of T.Cristatus may have paler hair, I think it's still not easy to distinguish them from T. germaini, especially when I see them in zoos that is not in their native country.