White rhinoceros characteristics, feeding, behavior

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Simon Doyle
White rhinoceros characteristics, feeding, behavior

The white rhino (Ceratotherium simum) it is a herbivorous mammal that lives in the African savannas. It is one of the largest land animals in the world, with an adult male weighing around 2300 kg. It belongs to the Rhinocerotidae family and together with horses, zebras, donkeys and tapirs they form the order Perissodactyla (perissodactyls).

The white rhino is the most common of the five species of rhino in the world. It is also estimated to be the most recent species of rhinoceros. Probably during the Pleistocene period, it diverged from the lineage of the genus Tell you.

White rhinoceros specimen

It is also the largest species of rhinoceros and, like the black rhinoceros, has been seriously affected by pseudo-hunting (sport hunting) and poaching, due to the increase in demand for products made with horn. these animals and their use as a hunting trophy.

The poaching of these animals is a global problem, which requires the attention of international entities that control the demand for them in those countries that promote their trade..

C. simum next to the black rhinoDiceros bicornis) are the two species of rhinoceros found in Africa, with populations that inhabit from the north and east of South Africa, to Zimbabwe and Botswana. At present, it has been introduced in Zambia and reintroduced in Swaziland, Kenya, Mozambique, Uganda and Namibia.

Article index

  • 1 General characteristics of the white rhino
  • 2 Taxonomy
  • 3 Conservation status
    • 3.1 - Southern white rhinoceros (C. s. Simum)
    • 3.2 - Northern white rhinoceros (C. s. Cottoni)
    • 3.3 - Poaching and illegal trafficking
  • 4 Habitat and distribution
  • 5 Playback
    • 5.1 Reproductive periods
    • 5.2 Reproductive behavior
  • 6 Food
  • 7 Behavior
  • 8 References

General characteristics of the white rhino

Male white rhino

White rhinos have a light grayish coloration. It is the fourth heaviest land mammal, in some cases exceeding 2300 kg. They can grow to around two meters high and four meters long..

Like the black rhino, it has two horns on the front of its face between the eyes and the nose. The horn located posteriorly has a blunt ending and is much shorter than the main horn, which has a pointed end.

The white rhinoceros is also known as the “square-lipped or wide-lipped rhinoceros” because their lips have a straight and wide appearance related to their feeding. This feature contrasts with the elongated mouth of the black rhino..

Unlike cows and bulls, rhinos do not have a true horn, since this is not an extension of the skull with bony conformation. The horn of these animals is formed mainly by keratin, so if it is lost in a confrontation it can be formed again.

Taxonomy

The species Ceratotherium simum was described by Burchell in 1817, who originally described it as Rinhoceros simum. Two subspecies of white rhino are currently known: the southern white rhino (Ceratotherium simum simum) and the northern white rhino (Ceratotherium simum cottoni).

These subspecies are geographically separated by the grasslands found in sub-Saharan Africa.. C. s. simum It is found in southern Africa, spreading in Botswana, Eswatini, Kenya, Namibia, South Africa, Zambia and Zimbabwe.

The northern subspecies C. s. cottoni It is currently made up of two individuals in the Kenyan nature reserve OI Pejeta. Originally, this subspecies inhabited the Democratic Republic of the Congo, Sudan and west of the Nile River in some parts of Uganda.

Some researchers believe that the northern subspecies should move up to species status. However, conservation biologists currently working with this subspecies, assure that it is very difficult to clarify this situation due to the small number of individuals, who also have genetic kinship with each other..

State of conservation

Rhinoceros female and calf

The white rhino is currently in the category of "near threatened" according to the International Union for Conservation of Nature (IUCN for its acronym in English).

Although the population of this species is increasing, its conservation status remains near threatened (NT: Near Threatened) due to the present increase in poaching due to the constant demand for the horn of these animals.

Added to this, the reduction in the budget for wildlife conservation, the new “medicinal uses” of the horns and the decrease in the distribution area of ​​this species, are situations that keep the white rhino under constant threat..

It should be noted that the conservation status of the two subspecies of the white rhinoceros varies considerably.

- Southern white rhino (C. s. simum)

Southern white rhinos (C. s. Simum) at the Lion Country Safari Reserve. Source: Duncan Rawlinson / CC BY (https://creativecommons.org/licenses/by/2.0)

Subspecies Ceratotherium simum simum It is classified as "near threatened" (NT) by the IUCN since 2011.

Since the mid-1990s, efforts have been made with great success to increase and conserve the populations of these rhinos, registering around 20,165 individuals in the wild in 2011..

However, since 2008 poaching has been on the rise. The latter related to an increase in the intervention of international criminal organizations in poaching to supply the growing demand for horns, as a consequence of new "non-traditional medicinal and aesthetic uses" in the Asian market..

During the present decade, poaching activities have been recorded in the main distribution areas of this subspecies, with mutilated animals being found in South Africa, Kenya, Zimbabwe and, for the first time since 1992, in Eswatini (or Swaziland).

It is estimated that since 2009 about 4,000 rhinoceros horns have been exported from Africa, of which more than 92% were obtained through poaching and mutilation of these animals.

- Northern white rhino (C. s. cottoni)

The northern white rhino subspecies is in the "Critically Endangered" (CR) category and is possibly extinct in the wild. This subspecies was found in the Garamba National Park and towards the northeast of the Democratic Republic of the Congo.

However, since 2006 there have been no sightings of this species in the wild..

Since 2009, the only population of C. s. cottoni It consisted of a group of five captive individuals in the OI Pejeta nature reserve in Kenya. However, the group was diminished after the death of two of the females in 2015.

During 2018 the last male of this group died, currently only two females remain, of which only one is still of reproductive age..

Efforts in the recovery of the subspecies C. s. cottoni

Due to the recent death of the only male of this subspecies, extinction appears to be inevitable for these rhinos. One of the possible solutions that have been studied to conserve the greatest number of adaptive genes of this animal is the crossing of individuals with the southern subspecies C. s. simum.

Through this method, it is hoped to reintroduce crossbred animals into the natural habitat of the northern subspecies, hoping that with the passage of time and geographical separation, these animals can resume their evolutionary adaptation..

However, the chances of success of these attempts to preserve the subspecies are really low since, even if the crossing of these subspecies were carried out, it would be necessary to completely eliminate the threat of poaching in the natural habitat..

In addition, if the effect of the genetic and demographic modeling of a small population is taken into account, the population growth to a stable number is not really viable..

On the other hand, advances in cell studies and the development of reproductive technologies such as cloning and artificial production of gametes from stem cells are possible solutions to prevent the extinction of this subspecies..

- Poaching and illegal trafficking

In 2013, a report issued by the IUCN and TRAFFIC (wildlife trade and trafficking monitoring network) ensures that in the last 20 years the illegal trade in rhinoceros horns has had the highest levels in history..

This has greatly affected conservation efforts that have taken place since the 1990s..

Africa is the main source of illegally trafficked horns around the world, mainly in Asia and Europe. The business of hunting and trafficking in these horns involves very well funded criminal organizations that are generally made up of Asian citizens..

These organized groups hired mainly Vietnamese and Thai nationals to carry out the hunt, simulating trophy hunts for illegal trade. But as of 2012, citizens of Vietnam were no longer able to obtain hunting licenses, an action carried out in the hope of reducing the poaching of endangered animals..

Habitat and distribution

Detailed image of the paw of a white rhinoceros (Ceratotherium simum), Zoo de la Palmyre, France. Source: William Scot / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.5)

There are records that indicate that this species also inhabited the Central African Republic and Chad, being currently extinct in these areas. It is believed to be extinct also in the Democratic Republic of the Congo, South Sudan and Sudan.

This species lives in subtropical dry scrub and grasslands and in savannas. It feeds exclusively on plant species that inhabit at ground level, in contrast to the black rhinoceros that feeds on shrub-like vegetation.

Reproduction

White rhinoceros female and calf

Heat in females lasts for about 30 days. The gestational period lasts between 16 and 19 months. Once the female has given birth to her calf, she maintains a lactation period of up to 18 months, entering the period of heat again when the calf is between eight and 12 months old..

The young remain with their mothers from birth to two or three years, when they become subadults. Juvenile females become sexually mature around the age of five, when they have their first estrous event. However, they are considered subadults once they have had their first calf, between the ages of six and seven..

Male individuals tend to become solitary at the age of ten and from that moment on they are considered as adults..

Reproductive periods

Reproduction in rhinos is not restricted to some time of the year and oestrus periods often coincide with parturitions in females. However, some studies have recorded peaks of estrous periods between November and February. During this period it is common to see some females accompanied by beta males.

Between the months of July and September there have been sightings of females accompanied by male alphas, which indicates another peak in the estrous period at this time. Beta males usually accompany a female for a few days, while alpha males do so for several weeks..

Reproductive behavior

If a female who is chased by a male enters the territory of another individual, the male tries to stop her by making different sounds such as loud screeches, repeatedly urinating and even confronting the female..

Once the female is ready for reproduction, the male performs repeated courtship movements. The male is located behind the female and generates gasping sounds, repeating the movements and sounds for a few hours

Once the female accepts the male, he places his chin on the female's rump and mounting attempts begin. Intercourse lasts 15 to 30 minutes and can occur repeatedly over one or several days..

Feeding

Ceratotherium simum simum grazing By David J. Stang [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]

The white rhinoceros is a herbivorous species, representing perhaps the largest animal that feeds exclusively on grasses found at ground level. Its wide lips work to pluck grass, usually located between two and five centimeters above ground level..

Short grasslands are the preferred grazing areas for these animals. Stoloniferous and leafy species with less fiber content abound in these pastures, resulting in more nutritious for rhinos.

During periods of drought, these grasslands are very unproductive, so the animals move to the remaining stands, feeding on slightly taller grasses, especially on Tremeda trianda.

Feeding periods generally occur in the morning and early evening, with grazing continuing for the rest of the night in various periods. Low metabolic rate per unit of body tissue is an important feature that prevents weight loss in lean periods.

Behaviour

White rhino with her calf covered in mud, Sabi Sand Game Reserve, South Africa. Source: Flickr user James Temple / CC BY (https://creativecommons.org/licenses/by/2.0)

White rhinos have a social structure with five categories: juveniles, sub-adults, females, alpha males, and beta males..

In general, adult rhinos are solitary, although groups of different numbers can be found. It is common to find aggregations of individuals sharing a resting or grazing place, but such aggregation dissolves as the individuals finish their activities and go their separate ways..

The groups that can be formed can be stable (if they last more than a month) or temporary (if they last less than a month).

Rhinos use their horns to communicate with each other. When two individuals meet, they move their heads and may bump their horns at different angles, sometimes accompanying these movements with sounds such as snorts or growls..

The angle of encounter between the horns and the sounds defines whether either individual is only giving a warning or whether the encounter will end in a confrontation. These are generally between male alphas defending their territories or the right to reproduce..

Male rhinos present territoriality, which is based on a dominance relationship, where alpha males defend their territory against rivals, although they can share it with other subordinate males..

References

  1. Emslie, R. (2011). Ceratotherium simum ssp. cottoni. The IUCN Red List of Threatened Species 2011: e.T4183A10575517. dx.doi.org. Downloaded on 22 October 2019.
  2. Emslie, R. (2011). Ceratotherium simum ssp. simum. The IUCN Red List of Threatened Species 2011: e.T39317A10197219. dx.doi.org. Downloaded on 22 October 2019.
  3. Emslie, R. (2012). Ceratotherium simum. The IUCN Red List of Threatened Species 2012: e.T4185A16980466. dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T4185A16980466.en. Downloaded on 21 October 2019.
  4. Harley, E. H., de Waal, M., Murray, S., & O'Ryan, C. (2016). Comparison of whole mitochondrial genome sequences of northern and southern white rhinoceroses (Ceratotherium simum): the conservation consequences of species definitions. Conservation Genetics, 17 (6), 1285-1291.
  5. Patton, M. L., Swaisgood, R. R., Czekala, N. M., White, A. M., Fetter, G. A., Montagne, J. P., Rieches, R. G. & Lance, V. A. (1999). Reproductive cycle length and pregnancy in the southern white rhinoceros (Ceratotherium simum simum) as determined by fecal pregnane analysis and observations of mating behavior. Zoo biology: 18 (2), 111-127.
  6. Owen-Smith, N. (1971). Territoriality in the white rhinoceros (Ceratotherium simum) Burchell. Nature, 231 (5301), 294-6.
  7. Owen-Smith, R. N. (1975). The Social Ethology of the White Rhinoceros Ceratotberium simum (Burchell 1817 *). Zeitschrift für Tierpsychologie, 38 (4), 337-384.
  8. Tunstall, T., Kock, R., Vahala, J., Diekhans, M., Fiddes, I., Armstrong, J., Paten, B., Ryder, O. A. & Steiner, C. C. (2018). Evaluating recovery potential of the northern white rhinoceros from cryopreserved somatic cells. Genome research, 28 (6), 780-788.

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