Desert warthog

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Desert warthog
Desert Warthog, Tsavo National Park, Kenya 01.jpg
P. aethiopicus delamerei
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Suidae
Genus: Phacochoerus
Species:
P. aethiopicus
Binomial name
Phacochoerus aethiopicus
(Pallas, 1766)
Subspecies
Phacochoerus aethiopicus map.svg

The desert warthog (Phacochoerus aethiopicus) is a mammalian, artiodactyl-ungulate species of the pig and swine family (Suidae) [2] native to the Horn of Africa region of East Africa. Two subspecies have been named: the Cape warthog (P. a. aethiopicus), which became extinct around 1865, had once inhabited South Africa, [1] while the extant Somali warthog (P. a. delamerei) is largely found in Kenya [3] and Somalia, [4] some areas of Ethiopia, and potentially still inhabits parts of Djibouti and Eritrea. [5]

Contents

Evolutionary history

Fossils have been found from the Holocene epoch showing that two divergent lines of warthogs (Phacochoerus spp.) were in existence thousands of years ago. The ancestors of the present day common warthog (P. africanus) had a different number of incisors than the ancestors of the desert warthog (P. aethiopicus) line. During the late nineteenth century, P. aethiopicus became extinct in South Africa. Subsequently, study of mDNA as well as morphological analysis has shown that the East African population of warthogs, previously thought to be a variant of the common warthog, are in fact surviving members of the putatively extinct P. aethiopicus. [6]

Description

Skull of a desert warthog Desert Warthog skull, Eastern Cape, South Africa.jpg
Skull of a desert warthog

The desert warthog is a stockily-built animal growing to an average length of 125 centimetres (49 in) and weight of 75 kilograms (165 lb) with males being larger than females. It has a rather flattened head with distinctive facial paired protuberances ("warts") and large curving canine teeth that protrude as tusks. These are not present in juveniles but grow over the course of a few years. They are larger in males than in females. The body is sparsely covered with bristly hairs and a more dense region of hairs runs along the spine and forms a crest. The tail is long and thin and is tipped with a small brush of coarse hair. The general colour is mid to dark brown but the crest is sometimes whitish. The desert warthog differs from the bushpig (Potamochoerus porcus) and the giant forest hog (Hylochoerus meinertzhageni) in having facial warts and proportionately larger tusks. [7]

Desert warthogs can be differentiated from the common warthog by their distinctive facial features, including curled back tips at the end of the ears, lack of incisors, and generally larger snout. The suborbital areas in desert warthogs are swollen in the form of pouches that often extend to the base of the genal warts; these same areas in common warthogs have no such pronounced swelling. The species also has more strongly hook-shaped "warts", a more egg-shaped head, thickened zygomatic arches, and enlarged sphenoidal pits. [8]

Distribution and habitat

The desert warthog is native to the Horn of Africa. Its current range extends from southeastern Ethiopia through western Somalia to eastern and Central Kenya. The subspecies P. a. aethiopicus, commonly known as the Cape warthog, used to occur in the southeastern parts of Cape Province and the adjacent parts of Natal Province but became extinct around 1871. The habitat of the desert warthog is open arid countryside including thin woodland with scattered trees, xerophytic scrubland and sandy plains, but not upland areas. It needs regular access to waterholes and so may occur near villages and places where water seeps to the surface in otherwise dry areas. [1]

Behaviour

Desert warthogs live in social groups called "sounders" consisting mostly of females and their offspring while males tend to live in solitude or form bachelor groups. A sounder occupies a home range of about 10 square kilometres (3.9 sq mi) which is usually centred on a water hole. The warthogs dig a number of burrows, or take over holes excavated by other animals, and move from one to another. Where the ranges of two different groups overlap, each may use the same burrow on different occasions. The groups do not interact to any great extent. [7]

Desert warthogs are diurnal and are largely herbivorous. One of the older females leads the group and they forage for grasses, leafy plants, flowers and fruit. They dig up rhizomes, edible tubers and bulbs with their snouts and tusks and will eat insects when food is scarce, and even carrion. They sometimes eat dung, including their own, and will tear bark from trees. [7]

Females come into oestrus every six weeks in the breeding season, which usually coincides with the end of the rainy season between March and May. Their frequent urination leaves scent markers that inform males of their receptive state. The gestation period is about 170 days and a litter of usually two or three piglets is born in one of the burrows. The young begin to emerge from the burrow for short periods when about three weeks old and as they get bigger they follow their mother closely. They are weaned at three or more months but remain dependent on their mother for several more months after that. She defends them from predators such as lions, leopards, cheetahs and hyaenas. The desert warthog has specific warning grunts that alert the rest of the group to danger. They may freeze initially but then rely on their speed to escape. They can travel for short distances at 55 kilometres (34 mi) per hour as they run to the safety of one of their burrows. The young dive in head first but the older animals reverse direction and back in so that they can defend themselves with their tusks. The juveniles become sexually mature at one to one and a half years and life expectancy is ten or more years. [7]

Research

Desert warthogs were experimentally infected with the virus that causes African swine fever. It was found that the warthogs showed no external signs of the infection but that they remained infective to domestic pigs for at least 33 days, this being the date on which the experiment terminated. [9] To reduce the risk of their animals being infected with this disease, farmers used to shoot desert warthogs. It is now realised that the disease is actually transmitted by the tick Ornithodoros moubata , and that elimination of warthogs in order to try to protect domestic swine serves no useful purpose. [7]

The desert warthog is an important host of the tsetse fly, [10] [11] and in some parts of its range efforts are being made to reduce warthog numbers because of this. [11] Specifically, P. aethiopicus was the preferred host for Glossina swynnertoni and G. pallidipes in a study by Weitz 1963. These resulted in variously 16% or 12% (depending on sample) of P. aethiopicus infected with trypanosomes. The trypanosomes found included Trypanosoma brucei by Geigy et al 1967 and T. congolense by Baker 1968. In cases of per-acute infection, Ashcroft 1959 and Geigy found P. aethiopicus to be suffering widespread haemorrhaging of serous membranes of their vital organs, hepatomegaly, splenomegaly, lymphadenopathy, and body fat atrophy. Torr 1994 found that the presence of P. aethiopicus may be more or less of a problem, depending on whether their associated Glossina can be controlled, which varies widely with the availability of specific attractants. [10]

Warthogs are prolific breeders and research is being performed into their breeding and recruitment patterns as a means of deciding how best to control them. [11]

Status

In its Red List of Endangered Species, the International Union for Conservation of Nature lists the desert warthog as being of "Least Concern". This is because it is common in some parts of its range and the population is thought to be stable. It occurs in a number of national parks and wildlife sanctuaries and it faces no significant threats although it may locally be hunted for bushmeat. It also faces competition at waterholes and for grazing with domestic livestock. [1]

Related Research Articles

<span class="mw-page-title-main">Tsetse fly</span> Genus of disease-spreading insects

Tsetse are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus Glossina, which are placed in their own family, Glossinidae. The tsetse is an obligate parasite, which lives by feeding on the blood of vertebrate animals. Tsetse has been extensively studied because of their role in transmitting disease. They have a pronounced economic impact in sub-Saharan Africa as the biological vectors of trypanosomes, causing human and animal trypanosomiasis.

<span class="mw-page-title-main">Common warthog</span> Wild member of the pig family

The common warthog is a wild member of the pig family (Suidae) found in grassland, savanna, and woodland in sub-Saharan Africa. In the past, it was commonly treated as a subspecies of P. aethiopicus, but today that scientific name is restricted to the desert warthog of northern Kenya, Somalia, and eastern Ethiopia.

<span class="mw-page-title-main">Trypanosomiasis</span> Medical condition

Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. In humans this includes African trypanosomiasis and Chagas disease. A number of other diseases occur in other animals.

<i>Trypanosoma</i> Genus of parasitic flagellate protist in the Kinetoplastea class

Trypanosoma is a genus of kinetoplastids, a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Euglenozoa. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous and most are transmitted via a vector. The majority of species are transmitted by blood-feeding invertebrates, but there are different mechanisms among the varying species. Trypanosoma equiperdum is spread between horses and other equine species by sexual contact. They are generally found in the intestine of their invertebrate host, but normally occupy the bloodstream or an intracellular environment in the vertebrate host.

<span class="mw-page-title-main">Red river hog</span> Species of pig

The red river hog or bushpig is a wild member of the pig family living in Africa, with most of its distribution in the Guinean and Congolian forests. It is rarely seen away from rainforests, and generally prefers areas near rivers or swamps.

<span class="mw-page-title-main">Bushpig</span> Species of mammal

The bushpig is a member of the pig family that inhabits forests, woodland, riverine vegetation and cultivated areas in East and Southern Africa. Probably introduced populations are also present in Madagascar. There have also been unverified reports of their presence on the Comoro island of Mayotte. Bushpigs are mainly nocturnal. There are several subspecies.

<span class="mw-page-title-main">African wild ass</span> Species of wild ass

The African wild ass or African wild donkey is a wild member of the horse family, Equidae. This species is thought to be the ancestor of the domestic donkey, which is sometimes placed within the same species. They live in the deserts and other arid areas of the Horn of Africa, in Eritrea, Ethiopia and Somalia. It formerly had a wider range north and west into Sudan, Egypt, and Libya. It is Critically Endangered, with about 570 existing in the wild.

<i>Metridiochoerus</i> Extinct genus of mammals

Metridiochoerus is an extinct genus of swine known from the Pliocene and Pleistocene of Africa. It is also known as the giant warthog.

<span class="mw-page-title-main">Warthog</span> Genus of wild pigs

Phacochoerus is a genus in the family Suidae, commonly known as warthogs. They are pigs who live in open and semi-open habitats, even in quite arid regions, in sub-Saharan Africa. The two species were formerly considered conspecific under the scientific name Phacochoerus aethiopicus, but today this is limited to the desert warthog, while the best-known and most widespread species, the common warthog, is Phacochoerus africanus.

<span class="mw-page-title-main">Suinae</span> Subfamily of mammals

Suinae is a subfamily of artiodactyl mammals that includes several of the extant members of Suidae and their closest relatives – the domestic pig and related species, such as babirusas. Several extinct species within the Suidae are classified in subfamilies other than Suinae. However, the classification of the extinct members of the Suoidea – the larger group that includes the Suidae, the peccary family (Tayassuidae), and related extinct species – is controversial, and different classifications vary in the number of subfamilies within Suidae and their contents. Some classifications, such as the one proposed by paleontologist Jan van der Made in 2010, even exclude from Suinae some extant taxa of Suidae, placing these excluded taxa in other subfamilies.

A warthog is a wild member in the Phacochoerus genus that lives in Africa. It consists of 2 species:

P. africanus may refer to:

<i>Ornithodoros moubata</i> Species of tick

Ornithodoros moubata, commonly known as the African hut tampan or the eyeless tampan, is a species of tick in the family Argasidae. It is an ectoparasite and vector of relapsing fever in humans, and African swine fever in pigs.

<span class="mw-page-title-main">Wallowing</span> Bathing in mud, water or snow

Wallowing in animals is comfort behaviour during which an animal rolls about or lies in mud, water or snow. Some definitions include rolling about in dust, however, in ethology this is usually referred to as dust bathing. Wallowing is often combined with other behaviours to fulfil its purpose; for example, elephants will often blow dirt over themselves after wallowing to create a thicker "coating", or pigs will allow the mud to dry before rubbing themselves on a tree or rock to remove ectoparasites stuck in the mud.

References

  1. 1 2 3 4 d'Huart, J.P.; Butynski, T.M.M. & De Jong, Y. (2016) [errata version of 2016 assessment]. "Phacochoerus aethiopicus". IUCN Red List of Threatened Species . 2016: e.T41767A99376685. doi: 10.2305/IUCN.UK.2016-1.RLTS.T41767A44140316.en . Retrieved 12 April 2022. Database entry includes a brief justification of why this species is of least concern.
  2. Grubb, P. (2005). "Order Artiodactyla". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 638. ISBN   978-0-8018-8221-0. OCLC   62265494.
  3. "Observations • iNaturalist". 11 March 2013.
  4. "Observations • iNaturalist". 1 March 2023.
  5. "Observations • iNaturalist". 12 December 2021.
  6. Randia, E.; D′Huart, J.-P.; Lucchini, V.; Aman, R. (2002). "Evidence of two genetically deeply divergent species of warthog, Phacochoerus africanus and P. aethiopicus (Artiodactyla: Suiformes) in East Africa". Mammalian Biology. 67 (2): 91–96. Bibcode:2002MamBi..67...91R. doi:10.1078/1616-5047-00013.
  7. 1 2 3 4 5 Winkelstern, Ian (2009). "Phacochoerus aethiopicus". Animal Diversity Web. University of Michigan. Retrieved 2013-09-04.
  8. d'Huart, Jean & Grubb, Peter. (2005). A photographic guide to the differences between the Common Warthog (Phacochoerus africanus) and the Desert Warthog (Ph. aethiopicus). Suiform Soundings 5(2): 5-9.. Suiform Soundings. 5. 5-9.07
  9. Thomson, G. R.; Gainaru, M. D.; Dellen, A. F. van (1980). "Experimental infection of warthog (Phacochoerus aethiopicus) with African swine fever virus". Onderstepoort Journal of Veterinary Research. 47 (1): 19–22. ISSN   0030-2465. PMID   7454231.[ permanent dead link ]
  10. 1 2 Mbaya, A. W.; Aliyu, M. M.; Ibrahim, U. I. (2009-04-02). "The clinico-pathology and mechanisms of trypanosomosis in captive and free-living wild animals: A review". Veterinary Research Communications . 33 (7). Springer: 793–809. doi: 10.1007/s11259-009-9214-7 . ISSN   0165-7380. PMID   19340600. S2CID   23405683.
  11. 1 2 3 Child, Graham; Roth, Harald H.; Kerr, Michael (1968). "Reproduction and recruitment patterns in warthog (Phacochoerus aethiopicus) populations". Mammalia. 32 (1): 6–29. doi:10.1515/mamm.1968.32.1.6 (inactive 2024-08-16). ISSN   1864-1547. S2CID   84253713.{{cite journal}}: CS1 maint: DOI inactive as of August 2024 (link)

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