We, humans, are part of an impressive lineup of mammals which belong to the order Primates. From the smallest of all primates, the Madame Berthe’s mouse lemur found in Madagascar, weighing all of 35 g., to the heaviest of them all, the gorilla, weighing up to 180 kg., primates comprise over 300 species of monkeys, lemurs, lorises, tarsiers, and finally the tailless group to which the Homo sapiens belongs to – the apes. Until very recently, only six great apes were known to man. Seven including man. The eighth ape species of orangutan, called the Tapanuli orangutan (Pongo tapanuliensis), was described from the island of Sumatra in 2017.
There are several notable morphological features that help distinguish primates from other terrestrial mammals, such as possession of flat nail/s, opposable thumbs (though not all primate species own one), teeth with rounded molars and premolars, brain size to body weight ratio, among others. Primates, it is most likely, evolved from an arboreal ancestor about 59-60 million years ago as per the earliest fossil records. Primates show a remarkable diversity in form and behaviour, especially locomotion. Among non-human primates, leaping and arm swinging (or brachiation), are exhibited among the canopy dwellers such as several species of monkeys and lemurs, while quadrupedalism is the norm among gorillas, chimpanzees, and certain macaques who largely move about on the ground. Only humans seem to display complete bipedalism among primates. It is fascinating to think about how closely related to our primate cousins we are. Humans, chimps and bonobos are almost completely genetically identical. After all, we share 98% of our DNA with each other!
India is blessed with an enviable diversity and abundance of primates. The country harbours 14 species of non-human primates – six macaque, five langur, two loris and one gibbon species. Among them, rhesus macaques (Macaca mulatta) and bonnet macaques (Macaca radiata) are widespread and a very common sight across India’s jungles and urban spaces. While gray langurs (Semnopithecus entellus), with their signature grey coats and black faces, too are a quintessential fixture of most Indian jungles across its range, including urban areas. Unfortunately, human-monkey conflict has become a serious wildlife and conservation issue in India. Habitat loss and intrinsic opportunistic tendencies see langurs and macaques often straying into human settlements by the lure of easy availability of food. Intensifying conflict in states such as Himachal Pradesh has forced forest and wildlife managers to resort to serious mitigation measures such as sterilisation.
In contrast, several primate species in India are extremely rare and severely threatened. The Gee’s golden langur (Trachypithecus geei), endemic to northeast India and Bhutan, is among the world’s most endangered primates. A few thousand individuals cling on to slivers of forests in western Assam. These arboreal monkeys are a sight to behold with their cream-golden coats which glisten under the sun. Down south, another endemic species of macaque makes the list of very many wildlife enthusiasts and photographers in India – the majestic lion-tailed macaque (Macaca silenus). But, rampant forest fragmentation and habitat degradation are serious threats facing these simians. Endemic to the Anamalai Hills in the Western Ghats, the lion-tailed macaques are witnessing an alarming behavioural adaptation to their rapidly changing and vanishing rainforest habitat. Certain populations of these otherwise canopy dwellers are seen interacting with tourists and local people a little too much for comfort. In the wild, they roost and forage among the tree canopies. But, now certain populations of macaques are increasingly accepting human offerings of packed and other types of unnatural and unhealthy food items.
India’s only known apes, the Hoolock gibbons, are found in the forest of northeast India. The western hoolock gibbon (Hoolock hoolock) and eastern hoolock gibbon (Hoolock leuconedys), are spread across various northeastern states with the former occupying a wider range. These vulnerable arboreal apes with their distinct, loud calls also known as ‘gibbon song’ are important seed dispensers and vital members of their ecosystem. But, severe fragmentation of their habitat, that is also shrinking and degrading, coupled with hunting, casts a troubled shadow over this ape species.
Ironically, the unnaturally destructive nature and actions of one kind of primate has, today, deemed the future for the rest of them rather uncertain and bleak.