28-5-2023 TABIN RESERVE, BORNEO - NORTH BORNEAN GREY GIBBON (Hylobates funereus) COURTESY OF MRS VALERIE FISHER

The eastern grey gibbon or northern grey gibbon (Hylobates funereus) is a primate in the gibbon family, Hylobatidae.

Formerly, the eastern grey gibbon and western grey gibbon (H. abbotti) were considered conspecific with the southern grey gibbon (H. muelleri), but more recent studies indicate that all three are distinct species, and both the IUCN Red List and the American Society of Mammalogists consider them such. However, they can still hybridize with one another where their ranges meet.

 It is endemic to northeastern Borneo, and is found in Kalimantan, Sarawak, and Brunei. It ranges from Sabah south to the Mahakam River in East Kalimantan, and west to Baram in Sarawak. 

27-5-2023 TABIN RESERVE, BORNEO - NORTH BORNEAN GREY GIBBON (Hylobates funereus)

As arboreal primates, northern gray gibbons spend the majority of their time in the forest canopy, rarely descending to the ground. They prefer mature primary and secondary forests, including Borneo's tropical evergreen dipterocarp forests, which provide them with safety and abundant fruit.

The Northern Grey Gibbon (Hylobates funereus) [also known as North Borneo Gibbon] is a small species of gibbon endemic to the tropical rainforests of northern and eastern Borneo. This species was previously considered a subspecies of Mueller’s Gibbon (Hylobates muelleri funereus) [ aka Bornean Gibbon] but has recently been recognized as a distinct species.

Similar to other gibbon species, Northern Grey Gibbons are highly vocal. The ‘great call’ of the female is characterized by accelerating whoops followed by a rapid series of bubbly notes. Male-female duets are an iconic sound of the Bornean rainforest at dawn.

 

28-5-2023 TABIN RESERVE, BORNEO - NORTH BORNEAN GREY GIBBON (Hylobates funereus)

 

The eastern grey gibbon or northern grey gibbon (Hylobates funereus) is a primate in the gibbon family, Hylobatidae.

Formerly, the eastern grey gibbon and western grey gibbon (H. abbotti) were considered conspecific with the southern grey gibbon (H. muelleri), but more recent studies indicate that all three are distinct species, and both the IUCN Red List and the American Society of Mammalogists consider them such. However, they can still hybridize with one another where their ranges meet.