Seven Worlds, One Planet – Sir David Attenborough’s latest wildlife documentary series – returns tonight with its second episode. This time we are going to explore Asia, the world’s largest continent. It is also the world’s most populous continent with a population of nearly 4.5 billion! This inconceivable number of people brings an immense amount of challenges as humans and wildlife struggle to coexist in such a crowded environment.
For the focus of this week’s blog post, I was torn between the golden snub-nosed monkey (Rhinopithecus roxellana) and the Sumatran rhino (Dicerorhinus sumatrensis), both of which are endangered and in need of our support. However, rhinos are fascinating to me (my first ever post on this blog was on the Javan rhino) and given that the population of Sumatran rhinos stands at fewer than 100 individuals, I believe this species needs all the help it can get.
Also known as the hairy rhino, the Sumatran rhinoceros could once be found in vast ranges of rainforests and swamps across Southeast Asia. Today, they can only be found in isolated populations on the islands of Sumatra and Borneo. Subsequently, they are listed as critically endangered. Sumatran rhinos are the smallest of the five rhino species and have two horns, unlike the two other Asian rhino species (the Javan and Indian) which just have one.
The Sumatran rhino is arguably the most unique of the rhino species alive today. Incredibly, it is thought that they are more closely related to the extinct woolly rhinos than to the rhinos alive today. They are covered with long hair that is reddish-brown in colour. Their two horns are far smaller than those of the white and black rhinos, with their larger horn only growing to around 20cm, although one recorded individual had a horn that was a mighty 81cm long!
Solitary creatures, Sumatran rhinos only come together for breeding and offspring rearing. They are folivores (herbivores specialised in eating leaves) and consume around 50kg of food every day! Their eating habits make them a keystone species. By consuming vegetation from a wide range of plant species, they help to disperse the plant’s seeds. This relationship allows the plant species to expand in size and distribution. In turn this provides food for other species in the food chain. Consequently, the loss of megafauna such as the Sumatran rhinoceros would have grave and far-reaching effects.
Decades of poaching and habitat loss have resulted in the Sumatran rhino’s downfall. Even though their horns are far smaller than their African counterparts, they are still hunted for it. Rhino horns have no proven medicinal value which is why this issue is so frustrating. The price of Sumatran rhino horns has been estimated as high as US$30,000 per kilogram. Tradition has tormented this species. Rhino horn is mostly made up of keratin – the same protein that makes up our hair and fingernails. If you want to use rhino horn for medicinal purposes, it would be more worthwhile to just bite your nails.
Sumatran rhinos do not cope well in captivity. Conservation organisations are working hard to protect the species in its natural habitat. By establishing rhino ‘sanctuaries’ in Sumatra and Borneo, they hope to create an area free from poaching where rhinos can live and breed in peace. Moreover, by relocating small isolated populations to larger ones they hope to increase the gene pool and improve the species’ chances of survival. With their population estimated at fewer than 100 individuals, the future of the Sumatran rhinoceros is uncertain. However, I believe that if we expand our conservation efforts, educate people on the importance of this species and reduce our demand for products such as palm oil, we can stack the odds in their favour.
Hennessy, K., Wiggins, V. (2014) Animal Encyclopedia: The Definitive Visual Guide. 2nd edn. London. Dorling Kindersley.
Seven Worlds, One Planet Trailer: https://www.youtube.com/watch?v=nm5XasUl7HM