Greetings, Vietnam’s brave Rhino Heroes! After a great holiday celebrating Hung Kings’ Festival, Victory Day (30/4), and International Workers’ Day (1/5), it’s time for Vietnamese people to get back to schools, and workplaces. Guess what! There is another upcoming day for animal lovers like us to join in and celebrate together, it is International Biodiversity Day!

The annual May 22nd was chosen to celebrate International Biodiversity Day by U.N General Assembly in 2000 to raise awareness about the importance of biodiversity. Biodiversity means the existence of various earthly life forms found in fauna, flora, and microorganisms. Despite differences, they contribute greatly to the sustainability of the ecosystem by interacting with each other in different ways such as mutualism, parasitism, hunting, etc. Genetic variation is the core factor that brings in biodiversity since it introduces diversity among species and subspecies. Rhinoceroses are not an exception! Up to now, the world has recognized five distinct rhinoceros species roaming the African savannas and Asian forests:

African rhinoceros

  • White rhinoceros (Ceratotherium simum)
  • Black rhinoceros (Diceros bicornis)

Asian rhinoceros

  • Indian rhinoceros (Rhinoceros unicornis)
  • Javan rhinoceros (Rhinoceros sondaicus)
  • Sumatran rhinoceros (Dicerorhinus sumatrensis)

On the occasion of this day, let us show you how diverse the rhinoceros species are and what you can do to preserve them.


White Rhinoceros (Ceratotherium simum) – Conservation Status: Vulnerable (IUCN)

The white rhinoceros (Ceratotherium simum), also known as the square-mouthed rhinoceros, is the largest rhinoceros species in existence. They are 2 meters tall, weighing 3500 kg, and possess the second largest pair of horns after that of the black rhinoceros. The anterior horn is 102 cm long while the posterior horn is smaller and about 55 cm long. In terms of longevity and reproduction, white rhinos can live from 35-40 years, females are pregnant for about 16 months. The white rhino has two subspecies, which are:

  • Southern white rhinoceros (Ceratotherium simum simum) – Conservation status: Vulnerable (according to IUCN): This is the predominant subspecies of the white rhino with more than 18,000 individuals distributed mostly in four countries. Africa South Africa, Namibia, Zimbabwe, Kenya.
  • Northern white rhinoceros (Ceratotherium simum cottoni) – Conservation status: Critically Endangered (CRI): in contrast to the southern subspecies, this number is 2 for the northern subspecies!!! That’s right, the Northern rhino subspecies had only two females left, Najin (34 years old) and Fatu (23 years old) when the last male named Sudan died, causing the extinction of the subspecies. This is unavoidable. However, scientists still did not give up and tried to save the future of the Northern white rhinoceros with artificial insemination (IVF) by combining eggs from a female with frozen sperm from the female. Sudanese males died to create embryos. According to LA Times, three embryos have been successfully created since January 2020 and are waiting to be implanted into a female of the Southern subspecies for surrogacy. Hopefully, the plan will be successful and we can see the Northern white rhinos walking in the future!

Photo: two females and also the last two individuals of the Northern white rhinoceros subspecies (Ceratotherium simum cottoni) Najin and Fatu (Source: Ben Curtis / Associated Press).

Black rhinoceros (Diceros bicornis) – Conservation status: critically endangered.

The black rhinoceros (Diceros bicornis), also known as the hook-lipped rhinoceros, make the snout on the rhinoceros angular, elongated and forms a V. Thanks to this feature, they can eat growing plants. growing on it as high as leaves, branches, etc. With a different diet, black rhinos can live with white rhinos, avoiding unnecessary conflicts. Black rhinos are smaller than white rhinos, they are about 1.7m tall at shoulder height and weigh 1300kg. However, the black rhino horn is larger than other types of rhino horn, with the front and rear horns measuring 130cm and 55cm respectively. In terms of lifespan, black rhinos can live from 35-50 years. A female adult is pregnant for 15-16 months and usually gives birth to an individual every 2.5-3 years. With a low and long-lasting reproductive capacity, the black rhino was subject to extinction at the hands of European hunters when they arrived on the Black Continent. The period 1960-1995 marked the serious collapse of this rhino species when there were only about 2,500 individuals left. However, Africa’s conservation policies have doubled the number of black rhinos to nearly 6,000 to date. Currently, the world has four subspecies:

– South Central Black Rhino (Diceros bicornis minor): the most numerous of the four subspecies, they are found in South Africa, Zimbabwe, and southern Tanzania and have been re-released in Botswana, Malawi, Swaziland, and Zambia.

–  Southwestern black rhinoceros (Diceros bicornis bicornis): lives in Nambia and South Africa.

– Eastern black rhinoceros (Diceros bicornis michaeli): the majority of individuals are distributed in Kenya, and a few are concentrated in northern Tanzania.

–  Western black rhinoceros (Diceros bicornis longipes): extinct.

Indian rhinoceros (Rhinoceros unicornis) – Conservation status: vulnerable

The Indian rhinoceros (Rhinoceros unicornis), also known as the great one-horned rhinoceros, belongs to the genus Rhinoceros along with the Javan rhinoceros (Rhinoceros sondaicus). The Indian rhinoceros is distributed in northeastern India and Nepal. This is the second largest rhino species after the white rhinoceros, with a shoulder height of about 2 m, and weighing about 3.5 tons. True to its name, the Indian rhinoceroses have only a relatively small horn compared to the African relatives, which are only about 25 cm long. They have different skins from their African relatives, their appearance is covered with tough, segmented skin with tubercles, making these animals resemble mighty warriors wearing majestic armor. However, the Indian rhinoceros also faced poaching and was stripped of its horn to serve traditional remedies with no scientific basis or to make ornamental products such as dagger handles. Thanks to effective conservation policies from Indian and Nepalese authorities, this rhino species has escaped extinction as now more than 4000 individuals are existing in Asia. Their lifespan is about 35-45 years, and the gestation period of the female is 15-16 months. Distributed in tropical and subtropical grasslands, savannas, and shrublands, the Indian rhinoceros choose grasses, shrubs, fruits, and aquatic plants to consume.

Sumatran rhinoceros (Dicerorhinus sumatrensis) – Conservation status: critically endangered

The Sumatran rhinoceros (Dicerorhinus sumatrensis) is the only extant Asian two-horned rhinoceros and the only species of the genus Dicerorhinus, which is also a cruelly related rhinoceros to the extinct woolly rhinoceros (Coelodonta antiquitatis). With a shoulder height of about 1.0-1.5 m, and weighing about 600-900 kg, the Sumatran rhinoceros is the smallest of the five rhino species today. The anterior and posterior horns are approximately 55 and 10 cm in length, respectively. So, with the remaining 4 species of rhinoceros being hairless, the Sumatran rhinoceros is covered with reddish brown hair and has fringed ears. Sumatran rhinos live about 35-40 years, females have a gestation period of 15-16 months and usually give birth to one individual every 3 years. The habitat of this rhinoceros is the tropical rainforests of Asia, so their diet consists of fruits such as mangoes, figs, leaves, branches, bark, etc. They once roamed the eastern Himalayas of Bhutan, eastern India, Myanmar, Thailand, Malaysia Peninsula, Vietnam, and China. However, because of indiscriminate hunting and deforestation activities by humans, the Sumatran rhinoceros can only be found in central Kalimantan in Borneo and Sumatra, specifically in 3 National Parks Bukit Barisan, Gunung Leuser, Way Kambas in Indonesia. The Sumatran rhinoceros population is currently only about 80 individuals in fragmented populations, making them one of the rarest mammals in the world. The Indonesian government and rhino experts worldwide agree that these fragmented rhino populations should be consolidated into a breeding facility so that prompt action can be taken to conserve the species.

Javan rhino (Rhinoceros sondaicus) – Conservation status: critically endangered

Javan rhino (Rhinoceros sondaicus), or lesser one-horned rhino, is one of the species belonging to the Asian rhinoceroses together with the Indian rhino (Rhinoceros unicornis) and Sumatran rhino (Dicerorhinus sumatrensis). Javan rhino’s appearance is quite similar to that of the Indian counterpart yet has a smaller horn and size with a should height of 4.6 to 5.8 feet, and a length of 10  to 10.5 feet, their weight ranging from 1.984 to 5.071 pounds. The Javan rhinoceros is covered with an armor-like skin coated with dusky grey color. The life expectancy of the Javan rhinoceros falls between 30-45 years. In terms of reproduction, a female gives birth to only one calf every 3-5 years. The Javan rhinoceroses were once widely distributed across Asian countries like India, Pakistan, and Southeast Asian countries including the Malay Peninsula, Myanmar, Indonesia, and Vietnam. Despite broad distribution, illegal poaching has greatly contributed to the drastic decline of the populations of Javan rhino, driving this mammal to the verge of extinction. The world has documented two subspecies:

  • Annamite Javan rhinoceros (Rhinoceros sondaicus annamiticus): declared extinct in Vietnam. The last individual was killed on April 29, 2010, in Cat Loc forest, Cat Tien National Park, Dong Nai, Vietnam.
  • Indonesian Javan rhinoceros (Rhinoceros sondaicus sondaicus): lives in Ujung Kulon National Park in Java, Indonesia. The number is about 80 individuals.

The present Javan rhinoceros is the rarest of all rhino species. However, the future of the Javan rhinoceros is still there since there was apopulation of rhinos living in Ujung Kulon National Park, Indonesia. Although the number of individuals is still very small, there is still a last hope to help the Javan rhinoceros escape from extinction. To do this, let’s each join hands to say NO to rhino horn!