Black Rhino

Diceros bicornis

General Description

Scientific Name: Diceros bicornis

Subspecies: 8 Subspecies

Southern/cape Black Rhino (D. b. bicornis)
Northeastern Black Rhino (D. b. brucii)
Chobe Black Rhino (D. b. chobiensis)
Ugandan Black Rhino (D. b. ladoensis)
Western Black Rhino (D. b. longipes)
Eastern Black Rhino (D. b. michaeli)
South-central Black Rhino (D. b. minor)
South-western Black Rhino (D. b. occidentalis)

Status: Critically endangered (Increasing)

Population Estimate: 3,142

Population in Assessed Areas: Confidential

Diet: Herbivore - grazer

Male Size: 1,000-2,600 Kgs

Female Size: 800 -1,250 Kgs

Trophy Size: N/a

Generation Length: 14.98 years

Reproductive Season: Year Round

Time of Activity: Diurnal/semi-nocturnal

Desert-Adapted-Black-Rhino-Namibia-5-c-Save-the-Rhino-International-1.jpg

Description: An adult black rhinoceros stands 132–180 cm (52–71 in) high at the shoulder and is 2.8–3.75 m (9.2–12.3 ft) in length. An adult typically weighs from 800 to 1,400 kg (1,760 to 3,090 lb), however unusually large male specimens have been reported at up to 2,896 kg (6,385 lb). The cows are smaller than the bulls. Two horns on the skull are made of keratin with the larger front horn typically 50 cm (20 in) long, exceptionally up to 135.9 cm (53.5 in).

The longest known black rhinoceros horn measured nearly 1.5 m (4.9 ft) in length. Sometimes a third, smaller horn may develop. These horns are used for defense, intimidation, and digging up roots and breaking branches during feeding. The black rhino is smaller than the white rhino and close in size to the Javan rhino of Indonesia. It has a pointed and prehensile upper lip, which it uses to grasp leaves and twigs when feeding, whereas the white rhinoceros has square lips used for eating grass. The black rhinoceros can also be distinguished from the white rhinoceros by its size, smaller skull, and ears; and by the position of the head, which is held higher than the white rhinoceros, since the black rhinoceros is a browser and not a grazer.

Their thick-layered skin helps to protect black rhinos from thorns and sharp grasses. Their skin harbors external parasites, such as mites and ticks, which may be eaten by oxpeckers and egrets. Such behavior was originally thought to be an example of mutualism, but recent evidence suggests that oxpeckers may be parasites instead, feeding on rhino blood. It is commonly assumed that black rhinos have poor eyesight, relying more on hearing and smell. However, studies have shown that their eyesight is comparatively good, at about the level of a rabbit. Their ears have a relatively wide rotational range to detect sounds. An excellent sense of smell alerts rhinos to the presence of predators.

Ecology: Black rhinos are herbivorous browsers that eat leafy plants, twigs, branches, shoots, thorny wood bushes, small trees, legumes, fruit, and grass. The optimum habitat seems to be one consisting of thick scrub and bushland, often with some woodland, which supports the highest densities. Their diet can reduce the number of woody plants, which may benefit grazers (who focus on leaves and stems of grass), but not competing browsers (who focus on leaves, stems of trees, shrubs or herbs). It has been known to eat up to 220 species of plants. They have a significantly restricted diet with a preference for a few key plant species and a tendency to select leafy species in the dry season. The plant species they seem to be most attracted to when not in dry season are the woody plants. There are 18 species of woody plants known to the diet of the black rhinoceros, and 11 species that could possibly be a part of their diet too. Black rhinos also have a tendency to choose food based on quality over quantity, where researchers find more populations in areas where the food has better quality. Black rhinos show a preference for Acacia species, as well as plants in the family Euphorbiaceae.

In accordance with their feeding habit, adaptations of the chewing apparatus have been described for rhinos. The black rhinoceros has a two phased chewing activity with a cutting ectoloph and more grinding lophs on the lingual side. The black rhinoceros can also be considered a more challenging herbivore to feed in captivity compared to its grazing relatives. They can live up to 5 days without water during drought.

Black rhinos live in several habitats including bushlands, Riverine woodland, marshes, and their least favorable, grasslands. Habitat preferences are shown in two ways, the amount of sign found in the different habitats, and the habitat content of home ranges and core areas. Habitat types are also identified based on the composition of dominant plant types in each area. Different subspecies live in different habitats including Vachellia and Senegalia savanna, Euclea bushlands, Albany thickets, and even desert. They browse for food in the morning and evening. They are selective browsers but, studies done in Kenya show that they do add the selection material with availability in order to satisfy their nutritional requirements. In the hottest part of the day they are most inactive- resting, sleeping, and wallowing in mud. Wallowing helps cool down body temperature during the day and protects against parasites. When black rhinos browse they use their lips to strip the branches of their leaves. Competition with elephants can cause the black rhinoceros to shift its diet, altering its selectivity with the absence of the elephant.

Behavior:

Black rhinos are generally thought to be solitary, with the only strong bond between a mother and her calf. In addition, bulls and cows have a consort relationship during mating, also subadults and young adults frequently form loose associations with older individuals of either sex. They are not very territorial and often intersect other rhino territories. Home ranges vary depending on season and the availability of food and water. Generally they have smaller home ranges and larger density in habitats that have plenty of food and water available, and vice versa if resources are not readily available. Sex and age of an individual black rhino influence home range and size, with ranges of cows larger than those of bulls, especially when accompanied by a calf. In the Serengeti home ranges are around 70 to 100 km2 (27 to 39 sq mi), while in the Ngorongoro it is between 2.6 to 58.0 km2 (1.0 to 22.4 sq mi). Black rhinos have also been observed to have a certain area they tend to visit and rest frequently called "houses" which are usually on a high ground level.[citation needed] These "home" ranges can vary from 2.6 km2 to 133 km2 with smaller home ranges having more abundant resources than larger home ranges.

Black rhinos in captivity and reservations sleep patterns have been recently studied to show that males sleep longer on average than females by nearly double the time. Other factors that play a role in their sleeping patterns is the location of where they decide to sleep. Although they do not sleep any longer in captivity, they do sleep at different times due to their location in captivity, or section of the park.

Black rhinos have a reputation for being extremely aggressive, and charge readily at perceived threats. Black rhinos will fight each other, and they have the highest rates of mortal combat recorded for any mammal: about 50 percent of males and 30 percent of females die from combat-related injuries. Adult rhinos normally have no natural predators, due to their imposing size, thick skin, and deadly horns. However, adult black rhinos have fallen prey to crocodiles in exceptional circumstances. Calves and, very seldom, small sub-adults may be preyed upon by lions as well.

Reproduction: The adults are solitary in nature, coming together only for mating. Mating does not have a seasonal pattern but births tend to be towards the end of the rainy season in more arid environments.

When in season the cows will mark dung piles. Bulls will follow cows when they are in season; when she defecates he will scrape and spread the dung, making it more difficult for rival adult bulls to pick up her scent trail. Courtship behaviors before mating include snorting and sparring with the horns among males. Another courtship behavior is called bluff and bluster, where the black rhino will snort and swing its head from side to side aggressively before running away repeatedly. Breeding pairs stay together for 2–3 days and sometimes even weeks. They mate several times a day over this time and copulation lasts for a half-hour.

The gestation period for a black rhino is 15 months. The single calf weighs about 35–50 kilograms (80–110 lb) at birth, and can follow its mother around after just three days. Weaning occurs at around 2 years of age for the offspring. The mother and calf stay together for 2–3 years until the next calf is born; female calves may stay longer, forming small groups. The young are occasionally taken by spotted hyenas and lions. Sexual maturity is reached from 5 to 7 years old for females, and 7 to 8 years for males. The life expectancy in natural conditions (without poaching pressure) is from 35 to 50 years

Conservation Analysis

Map of Black Rhino Historical Distribution

Current & Historic range: As with many other African Megafauna, black rhinos likely had a wider range in the North Africa in prehistoric times than today. However this seems to have not been as extensive as that of the white rhino. Unquestionable fossil remains have not yet been found in this area and the abundant petroglyphs found across the Sahara desert are often too schematic to unambiguously decide whether they depict black or white rhinos. Petroglyphs from the Eastern Desert of southeastern Egypt relatively convincingly show the occurrence of black rhinos in these areas in prehistoric times.

The natural range of the black rhino included most of southern and eastern Africa, except the Congo Basin, the tropical rainforest areas along the Bight of Benin, the Ethiopian Highlands, and the Horn of Africa. Its former native occurrence in the extremely dry parts of the Kalahari desert of southwestern Botswana and northwestern South Africa is uncertain. It was abundant in an area stretching from Eritrea and Sudan through South Sudan to southeastern Niger, especially around Lake Chad. Its occurrence further to the west is questionable, although this is often claimed in literature. Today it is found only in protected nature reserves, having vanished from many countries in which it once thrived, especially in the west and north of its former range. The remaining populations are highly scattered. Some specimens have been relocated from their habitat to better protected locations, sometimes across national frontiers. The black rhino has been successfully reintroduced to Malawi since 1993, where it became extinct in 1990. Similarly it was reintroduced to Zambia (North Luangwa National Park) in 2008, where it had become extinct in 1998, and to Botswana (extinct in 1992, reintroduced in 2003).

In May 2017, 18 eastern black rhinos were translocated from South Africa to the Akagera National Park in Rwanda. The park had around 50 rhinos in the 1970s but the numbers dwindled to zero by 2007. In September 2017, the birth of a calf raised the population to 19. The park has dedicated rhino monitoring teams to protect the animals from poaching.

In October 2017, The governments of Chad and South Africa reached an agreement to transfer six black rhinos from South Africa to Zakouma National Park in Chad. Once established, this will be the northernmost population of the species. The species was wiped out from Chad in the 1970s and is under severe pressure from poaching in South Africa. The agreement calls for South African experts to assess the habitat, local management capabilities, security and the infrastructure before the transfer can take place.

Black Rhino Population Data

Current & Historic Populations: Throughout most of the 20th century, the Black Rhino was the most numerous of the world's rhino species. Relentless hunting of the species and clearances of land for settlement and agriculture reduced numbers and by 1960 only an estimated 100,000 remained. Between 1960 and 1995, large-scale poaching caused a dramatic 98% collapse in numbers with numbers bottoming out in the mid 1990s. Over this period numbers only increased in South Africa and Namibia. From 1992–1997 total numbers remained relatively stable with increases in some countries (those with the best-protected and managed populations) being cancelled out by declines in others. However, since the lows of the mid-1990s, Black Rhino numbers at a continental level have more than doubled reaching and estimated 5,495 by end 2017 (Emslie et al. 2019) and 5,630 by end 2018.

Increases in numbers have occurred in countries where investments in conservation programs, including monitoring and law enforcement, have been high. As of 2017 four Range States (South Africa, Namibia, Zimbabwe and Kenya) conserved the majority (93.9%) of remaining wild Black Rhinos.

Country	Population Estimate	Population Status	Last Assessed
Zimbabwe
Zambia
Uganda
Tanzania
South Sudan
Rwanda
Nigeria
Mozambique
Malawi
Kenya
Gabon
Equatorial Guinea
Democratic Republic of Congo
Central African Republic
Cameroon
Angola
South Africa

*Further data on Common Hippo populations and harvest numbers outside of South Africa and Namibia are largely incomplete, and hence it has not been evaluated by us. It is our goal to expand into other African Nations soon, so please do be patient with us.

Threats to Species Survival: The main threat to the species is Poaching to supply the illegal international rhino horn trade. It is estimated that currently around 95% of rhino horn sourced in Africa for end user illegal markets in SE Asia are from this source (Emslie et al. 2019). Rhino horn has traditionally had two main uses: use in Chinese medicine, and ornamental use. Recently rhino horn has become a highly prized material for making carved expensive high-status items such bowls and bangles. In the past it was also used to produce ornately carved handles for ceremonial daggers (jambiyas) worn in Yemen and some Middle East countries. Historically rhino horn was also used in traditional Chinese medicine (as a fever reducer). However, most recently it appears to be shavings from carvings that are illegally sold to the medicinal market at lower prices than worked items. While Black Rhino numbers continue to increase at a continental-level poaching has slowed overall growth. Some populations have also declined. Black rhino poaching peaked in 2015 and has been declining since. See Figure 2 and Table 2 and 3 in attached Supplementary Information file.

The significantly increased poaching since 2007 has greatly increased protection costs and risks to investment and staff. This has resulted in reduced incentives. Some private owners in South Africa have got rid of their rhino. If this worrying trend continues this threatens to possibly reverse the expansion of range and has the potential to also reduce conservation budgets and incentives to conserve Black Rhino privately (both those privately owned and those managed for the state on a custodianship basis (due to declining live sales and greatly increased protection costs )

Recommended Conservation Actions:

Further resource and manage protected areas where the Black Rhino exist.
Increase the access to funding and the effectiveness of anti-poaching techniques across Southern Africa, to make rhino protection as affordable as possible.
Encourage the implementation of economic incentives that allow landowners to profit off the presence of healthy Black Rhino populations, whether that be through hunting or ecotourism.
Improve survey methods to get accurate population data, such as implementing long-term monitoring programs.

Economic & Cultural Analysis

Ecotourism Value: Extremely High

Hunting Value: Extremely High

Meat Value: Moderate-high

Average Trophy Value: $150,000 - $350,000 USD

Vita Dart Price: $8,000 - $22,000

Meat Yield per Animal: 800-1,800 kg

Economic Value/Impacts: The Black Rhino presents considerable value to both the ecotourism and hunting industries across their range, as well as to rural and hunter-gatherer peoples that have likely hunted and lived alongside this species for thousands of years. Their large body size meant that each animal produces a considerable amount of meat, that can feed and entire village for weeks.

Black Rhinos are one of the most iconic wildlife species on the African continent, matched only by lions and elephants. Because of this, the mere presence of Rhinos of any species on a property can be a significant drawcard for ecotourism reserves, and are often one of the most sought after species on game drives. This value is realized across numerous game reserves in South Africa and Namibia, that take on the expenses of protecting them from the onslaught of poachers, because tourists are highly motivated to visit reserves with abundant populations of rhinos.

As rhinos numbers have begun to increase in South Africa and Namibia, limited trophy hunting has also been identified as a sustainable source of revenue for reserves, some of which have excess animals that can't just be relocated onto other reserves across the country. Prices of these rhino hunts can be astronomically high, with a mature bull tag being sold in 2014 for $350,000 USD. Another alternative hunting revenue stream based of White Rhinos are Vita Dart hunts, where the animal isn't actually killed, but instead just partially sedated for veterinary checkups. The price for such hunts is usually between $8,000 USD to $22,000 USD, depending on the animal and the lodge.

Cultural Value: Historically, the major factor in the decline of Black rhinos was uncontrolled hunting in the colonial era, but now poaching for their horn is the primary threat. They were prized for their impressive trophy size and unfriendly disposition, which compared to other living rhino species (bar the white rhino) is significantly larger.

Despite the lack of scientific evidence, the rhino horn is highly prized in traditional Asian medicine, where it is ground into a fine powder or manufactured into tablets to be used as a treatment for a variety of illnesses such as nosebleeds, strokes, convulsions, and fevers. Due to this demand, several highly organized and very profitable international poaching syndicates came into being and would carry out their poaching missions with advanced technologies ranging from night vision scopes, silenced weapons, darting equipment, and even helicopters.

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