A mysterious monkey photographed several times in the Lower Kinabatangan Wildlife Sanctuary in Sabah is now thought to actually be a hybrid between a proboscis monkey and silvered leaf monkey.
Multiple observers have recorded the two species living in mixed-species groups and interspecific mating has been photographed. The putative hybrid is now an adult female and was last seen in September 2020 with an infant and swollen breast, indicating that it is fertile.
The hybridisation may be due to anthropogenic changes to the landscape, where the expansion of oil palm plantations are confining both species to narrow riverine forest patches along the Kinabatangan.
The full research article (with photographs) can be found here:
Is Malaysia’s “mystery monkey” a hybrid between Nasalis larvatus and Trachypithecus cristatus? An assessment of photographs
Multiple observers have recorded the two species living in mixed-species groups and interspecific mating has been photographed. The putative hybrid is now an adult female and was last seen in September 2020 with an infant and swollen breast, indicating that it is fertile.
The hybridisation may be due to anthropogenic changes to the landscape, where the expansion of oil palm plantations are confining both species to narrow riverine forest patches along the Kinabatangan.
The full research article (with photographs) can be found here:
Is Malaysia’s “mystery monkey” a hybrid between Nasalis larvatus and Trachypithecus cristatus? An assessment of photographs