SCIENCE with Ms Lun
Rhinoceros
Species
There are 3 subspecies of the black rhino and 2 subspecies of the white rhino.
Diceros bicornis
- Diceros bicornis minor
- Diceros bicornis bicornis
- Diceros bicornis michaeli
Ceratotherium simon
- Ceratotherium simon cottoni
- Ceratotherium simon simum
Rhinoceros sondaicus
Dicerorhinus sumatrensis
Rhinoceros unicornis
Black rhinoceros
- South-central black rhino
- South-western black rhino
- East African black rhino
White rhinoceros
- Northern white rhino
- Southern white rhino
Javan rhinoceros
Sumatran rhinoceros
Greater one horn rhinoceros
Population
As a species, the black rhino is listed by the IUCN in 2020 as Critically Endangered. There website states there are 3,142 black rhino with numbers increasing. However, numbers are now over 6,421, thanks to conservation efforts (see Save the Rhino website).
The white rhino is listed by the IUCN in 2020 as Near Threatened. There are only 2 female Northern white rhinos left (the last male died in March 2018) and they are kept under guard at Kenya’s Ol Pejeta Conservancy. The Southern White rhino was thought to be extinct in the late 19th century but in 1895, a small population (<100) was discovered in Kwazulu-Natal, South Africa. Now the Southern white has a population of 17,464.
Both the Javan and Sumatran rhinos are critically endangered (as at 2019) with around 18 and 30 individuals respectively. The Greater one horn rhino was assessed in 2018 as Vulnerable. There are 4,018 individuals according to Save the Rhino.
Size
The white and greater horn rhinos are the largest species of rhino.
The white rhino stands 1.5 - 1.8m tall at the shoulder. They weigh between 1,700 to 2,400 kg and is 3 - 5 m long. The Greater on horn rhino is slightly larger than the white rhino.
The black rhino stands 1.4 - 1.7m at the shoulder and weighs between 800 and 1,350 kg. They are 3 - 3.8 m long.
The Javan is slightly larger than the black rhino and the Sumatran is the smallest of all the species (height: 1.0 -1.5m, weight: 600 – 950 kg and length: 2.0 – 3.0m).
Habitat & distribution
Black rhino: grasslands, savannahs and tropical bush lands.
White rhino: long and short-grass savannahs.
Javan: now only found in the rainforests of Indonesia’s Ujung Kulon National Park in west Java.
Sumatran: dense tropical forest (lowland and highland) mainly on the Indonesian island of Sumatra.
Greater one horn: in riverine (floodplain) grasslands and adjacent woodland in northern India and southern Nepal
Prized for their horns
Both species of the African rhino have 2 horns. With a front horn that can grow to 1.3 m for the black and 2 m for the white rhino, it's no wonder why these animals were hunted for the horns. Even the second, smaller horn could grow to 55cm.
Rhino horns are prized in the Asian market.
Male Javan rhinos have a single horn that is 25 cm long. Females have a smaller or no horn.
Sumatran rhinos are the only Asian rhino with two horns. The front horn is 25-79 cm long. The second horn is smaller, usually less than 10 cm.
Greater one-horned rhino has a single horn 20 to 61 cm long.
Diet
The black rhino is a browser and eats leaves, shoots and branches. The black rhino has a different mouth shape to the white rhino. The black rhino has a narrow upper lip and slightly hooked (prehensile), and adaptation for grabbing and ripping leaves.
In contrast, the wide flat mouth of the white rhino is adapted for grazing on grass.
Interesting facts
~ White rhinos were named not because of the colour but because of a mis-translation of the Dutch word 'wijde' meaning 'wide'. This refers to the wider, flatter mouth of this rhino species.
~ Sumatran rhinos can be covered with fur!
Group
White rhinos: females can form groups of up to 14. The group is mainly females with calves. Males are usually solitary and can be territorial (a range of 2.6 square kilometres. Female territory ranges can be 7 times larger and overlap with other females.
Breeding & lifespan
The gestation period is 15-16 months.
Lifespan in the wild is 35-40 years.
Predators & threats
Poaching still remains a problem.
Conflict from janjawood militia and Lord's Resistance army in the Democratic Republic of Congo has contributed to the near extinction of the Northern white rhino.