Pygathrix cinerea

The grey-shanked douc langur (Pygathrix cinerea) is a douc species native to the Vietnamese provinces of Quảng Nam, Quảng Ngãi, Bình Định, Kon Tum, and Gia Lai. The total population is estimated at 550 to 700 individuals. In 2016, Dr Benjamin Rawson, Country Director of Fauna & Flora International - Vietnam Programme, announced a discovery of an additional population including more than 500 individuals found in Central Vietnam, bringing the total population up to approximately 1000 individuals. P. cinerea was originally described as a subspecies of P. nemaeus in 1997, but later elevated to species status due to morphological differences. Other research has shown significant genetic differences as well. This species does sometimes hybridize with P. nemaeus. Grey-shanked doucs are very similar in appearance to P. nemaeus. They are light grey with a pale underside. Their feet and hand are black and their shins are a dark grey. The face is brownish orange on top with a white chin. Hair around the chin is white. The throat is white and lined on the bottom with an orange, brown collar. Males are slightly larger than females averaging 10.9 kg. Females average about 8.2 kg. Grey-shanked doucs are diurnal and primarily arboreal. They move about through trees by jumping and brachiating. In the past they have been found in groups as large as fifty individuals but those numbers have been greatly reduced to 4 to 15 individuals. Males are the dominant gender and dominance hierarchies have been observed while in captivity. The grey-shanked douc langur communicates using touch, visual communication, and sound. Growls are used to show aggression. They can be used as a threat or warning toward other individuals. A soft, twitter sound is used when being submissive. Grey-shanked doucs also engage in grooming to remove parasites and to establish and strengthen bonds between group members. This is usually done before resting for the night. Group members will also spar with each other. Sparring is a type of aggressive behavior in which participants will slap, pull, and grab each other. Visual communication includes facial expressions and various postures. Facial expressions include grimacing, which is used to show submissiveness, play face, which is used to play with another group member, and staring which suggests either curiosity or aggression. Facial expressions are also used during courtship. The male will make faces at the female indicating that he is ready to copulate. Grey-shanked langurs are primarily folivourous but will also eat other plant parts such as seeds, fruits, and flowers. They prefer young leaves and fruit that has not yet fully ripened.