What is the Tonkin snub-nosed monkey?
The Tonkin snub-nosed monkey (Rhinopithecus avunculus), unfortunately most people have never even heard of it, but those that have know it is incredibly rare. So rare in fact it has held residency on the list of the world's 25 most endangered primates since 2000.
But what is it besides a monkey? Actually it is one of four snub-nosed species which form a group of under-researched monkeys, the fourth was only discovered in 2012! Even amongst this bizarre group of relatives the Tonkin snub-nosed monkey still stands out. Firstly it is the only snub-nose to be found in Vietnam while the rest live in China. It inhabits much warmer climates and tropical rainforest while the other snub-nose monkeys can live in pine forests with yearly snowfalls! The warmer climate allows it to have a much slighter frame than its relatives and it glides through the treetops with ease rarely coming to the ground.
The TSNM is known as a Lazarus species relating to the story of Lazarus rising from the dead, in the case of the TSNM, it was thought extinct from 1986 to 1990. Currently only 4 known populations exist with a total of less than 200 individuals left in the wild. The largest population of 90 monkeys can be found in Khau Ca of the Ha Giang province in the very North of Vietnam. The second largest population of about 40 is 35km north of Khau Ca in the Ha Giang Province right on the border with the Yunnan province of China.
The overall appearance is almost comical! It is a black and white monkey with thick, rose pink lips and baby blue patches round the eyes, a flattened face with an upturned nose, that locals say makes them sneeze in the rain. The upper parts are black, the underparts creamy-white and there is an orange patch on the throat, particularly obvious in breeding males. The tail has a white tip. Males are larger than females at 14kg and 1.5m from head to tail and Juveniles are grey rather than black and lack the orange throat patch.
They generally form one male units this means that groups consist of multiple females and young males that are not yet mating. This can be up to 30 monkeys in size (but possibly used to be as high as 100!). It selctivley eats the parts humans would find a bit bitter such as unripe fruits, seeds and leaves from as many as 52 plants species.
They have a large vocal repetoire with the most common call being a hiccup (“huu chhhk”) sound which is used either in alarm calls or to communicate with other individuals. They usually use this sound in travelling or finding food. It is possible that they also communicate with the use of pheremones, but there has been no research as yet.
Special fact: This species has been observed on only a handful of accounts but it is confirmed by most accounts that mating is instigated by the female. She does this by approaching a male and making eye contact before running away and flashing her genitals. If the male is interested (which is not always) then he will join her.
