Pig hybrids

Family Suidae

Mammalian Hybrids

EUGENE M. MCCARTHY, PHD GENETICS, ΦΒΚ

Babyrousa babyrussa [Babirusa]
× Sus scrofa (♀) [Domestic Pig] CHR. CON: Indonesia. This cross, previously thought to be "impossible" was recently obtained, by accident, at the Copenhagen Zoological Gardens. See the separate article "Babirusa x Domestic Pig."

Hylochoerus meinertzhageni [Giant Forest Hog]
× Hylochoerus rimator [West African Forest Pig] In most taxonomies, three African pig populations meinertzhageni, of eastern Africa, rimator, of central Africa, and ivoriensis, of western Africa, have been lumped as subspecies of H. meinertzhageni. However, Melletti and Meijaard (2017, p. 8) treat them separately and state that hybrids between meinertzhageni and rimator may occur in the Ituri rainforest, northeastern Democratic Republic of the Congo, formerly called Zaire.
× Pan troglodytes [Chimpanzee] See the separate article "The Gorilla and the Koolokamba."

Hylochoerus rimator [West African Forest Pig] See: Hylochoerus meinertzhageni

Phacochoerus aethiopicus [Desert Warthog]
× Phacochoerus africanus [Warthog] No hybrids are as yet reported. The epithet Phacochoerus aethiopicus,was formerly applied to the Cape Warthog of S. Africa. However, d’Huart and Grubb (2001) have recently pointed out that a surviving population, delemerei, in the Horn of Africa is nearly identical to the Cape Warthog, which had been thought to be extinct for more than a century. Thus, delemerei is an extant representative of P. aethiopicus. The IUCN states that a future research priority for Phacochoerus is to "investigate the systematic and ecological relationships between P. aethiopicus [i.e., P. aethiopicus delemerei] and P. africanus at the edges of their respective distributions in northern Kenya, eastern Ethiopia and north-west Somalia, and determine whether allopatry, sympatry or intergradation [i.e., hybridization] occurs in these areas."

Phacochoerus africanus [Warthog]
× Sus scrofa [Domestic Pig] In his description of southern Africa Anders Sparrman (1786, vol. II, p. 26), the Swedish naturalist and disciple of Carl Linnaeus, mentions that a litter of these hybrids was farrowed on a South African farm. He also mentions that another well-known naturalist, Peter Simon Pallas, had attempted to produce this same cross and failed. There do not seem to be any modern reports of such a hybrid.

Potamochoerus larvatus [Bush Pig]
× Potamochoerus porcus [Red River Hog] ENHR(central Africa). There is a broad hybrid zone in central and eastern Democratic Republic of Congo, and in southern Sudan (Kingdon 1979, p. 201). These taxa are sometimes lumped. Additional information can be found here and here.
× Sus scrofa [Domestic Pig] Hybridization occurred in the Transvaal in the early 1970’s, when an escaped domestic sow mated with a bush pig. The resulting litter of eight had bush pig traits (Smithers 1983, p. 587; Milstein 1971 (cited in Smithers)). Layard, quoted in Gray (1869, p. 398), says "the hybrid is prolific."

Potamochoerus porcus [Red River Hog]
See also: Potamochoerus larvatus.
× Sus scrofa [Domestic Pig] ONHR(Gabon). Contact occurs where introduced Eurasian wild pigs have become established in Burkina Faso, Gabon and, probably, Dem. Rep. Congo. East 1990.

Sus ahoenobarbus [Palawan Bearded Pig] See: Sus barbatus × S. cebifrons.

Sus andamanensis [Andaman Pig] See: Sus celebensis × S. scrofa.

Note: Domestic pigs are commonly kept in outlying human settlements adjacent to remaining forest refugia harboring endangered or near endangered types of wild pigs. The IUCN says this "poses a potentially severe risk of disease transmission and/or genetic contamination to wild pig populations through increased likelihood of their contact with free-ranging domesticates." Three pigs are mentioned in this connection: Sus barbatus, S. cebifrons, and S. philippensis.

Sus barbatus [Bearded Pig]
× Sus cebifrons [Visayan Warty Pig] NHI. The Palawan Bearded Pig (Sus ahoenobarbus) is probably this hybrid. The Wild Pig Specialist Group states that "hybridization may have occurred between barbatus and cebifrons, so that ahoenobarbus maintains characteristics of both species" (accessed: 6/29/2013). The distribution of ahoenobarbus on Palawan and adjacent islands is geographically intermediate between those of barbatus and cebifrons, and land bridges connecting their ranges existed during past Pleistocene glaciations that could potentially have brought barbatus and cebifrons into breeding contact. Sus ahoenobarbus is thus geographically and morphologically intermediate a PHP of this cross.
× Sus scrofa [Domestic Pig] CHR. HPF(♂&♀). S. scrofa is feral throughout much of S. barbatus’s range (Malay Peninsula, Sumatra, Borneo, and adjacent islands). Hertwig 1936; Lotsy 1922; Mohr 1960.

Sus cebifrons [Visayan Warty Pig]
See also: Sus barbatus.
× Sus scrofa [Domestic Pig] ONHR(Philippines). A hybrid was captured near Basay in the southeastern part of Negros Island. Oliver states that "remaining populations [of S. cebifrons] are declining as a result of continued habitat destruction and intense hunting pressure. These populations are also potentially seriously threatened by "genetic contamination" through interbreeding with free-ranging domestic and feral pigs." See note immediately preceding Sus barbatus. S. cebifrons was until recently treated as a race of S. barbatus. Oliver 1992.

Sus celebensis [Sulawesi Wild Boar]
× Sus scrofa [Domestic Pig] The common pigs of New Guinea and parts of the Moluccas group are hybrids between S. celebensis and the common pig. Indeed, Groves showed that the second member of Sus to be described as a species, Sus papuensis of New Guinea, is almost certainly a hybrid of S. scrofa and S. celebensis. The pigs on which S. papuensis is based either arose through hybridization after the parental types were introduced to New Guinea or arose elsewhere and were themselves introduced. Similar hybrids also occur in the Moluccas, on Seram, Flores, Timor, and some nearby small islands (Nowak 1999, p. 1057). An IUCN website says, “there are other populations of hybrid feral pigs in the Moluccas which are practically indistinguishable from the New Guinea pigs, as well as apparently pure-bred derivatives of each of these species [i.e., S. celebensis and S. scrofa] on some other islands in this group, and in the Lesser Sunda chain of islands.” “Similarly,” says another IUCN site “the so-called ‘S. timoriensis’ of Timor and 'S. mimus’ of Simeulue Island (off N. W. Sumatra) are both highly modified introduced forms of S. celebensis, whereas ‘S. andamanensis’ and ‘S. nicobaricus’ of the nearby Andaman and Nicobar Islands (Bay of Bengal) are both highly modified forms of S. scrofa.” Until recently, S. celebensis was treated as a race of S. barbatus. Groves 1981.

Sus oliveri [Mindoro Warty Pig]
× Sus scrofa [Domestic Pig] NHR. CON: Mindoro Island in the central Philippines. The Wild Pig Specialist Group states that "Hybridization [of Sus oliveri] with free-ranging domestic pigs introduced and maintained by hinterland communities is an additional and likely serious threat" (accessed 6/29/2013). See also Melletti and Meijaard (2017, p. 163)

Sus papuensis [Papuan Pig] See: Sus celebensis × S. scrofa.

Sus philippensis [Philippine Warty Pig]
× Sus scrofa [Domestic Pig] CHR. CON: Philippines. The IUCN says hybridization with feral domestic pigs threatens the genetic integrity of Sus philippensis. See note immediately preceding Sus barbatus.

WILD BOAR X DOMESTIC HYBRIDA hybrid between a wild boar and a domestic pig (Wikimedia, public domain).

Domestic pigs vs. wild boars: Duff and Lawson treat domestic pigs and Eurasian wild boars as separate species, Sus domesticus and S. scrofa. And the two do differ in chromosome counts (the domestic pig has 2n=38 and wild boars have 2n=36). On this page, however, the name Sus scrofa refers to the domestic pig. Domestic pigs and wild boars produce partially fertile hybrids together. Andersson (1997) used crosses between wild boar and domestic pig to map phenotypic trait loci. Wikipedia has the following to say about an unually large wild hybrid of this type:

Hogzilla was a male hybrid of wild hog and domestic pig that was shot and killed by Chris Griffin in Alapaha, Georgia, United States, on June 17, 2004 on Ken Holyoak’s fish farm and hunting reserve. It was alleged to be 12 feet (3.7 m) long and to have weighed over 1,000 pounds (450 kg). Originally, it was widely considered a hoax. However, the animal’s remains were exhumed in early 2005 and studied by Dr. Oz Katz and his father, Dr. Eliahu Katz. The latter coined the name "Hogzilla". In March 2005, these scientists confirmed that Hogzilla actually weighed 800 pounds (360 kg) and was between 6.9 feet (2.1 m) and 8.6 feet (2.6 m) long, diminishing the previous claim. DNA testing was performed, revealing that Hogzilla was a hybrid of wild boar and domestic pig (Hampshire breed). However, compared to most wild boars and domestics, Hogzilla is still quite an extraordinary specimen. His tusks, which were asymmetric in length, measured nearly 28 inches (71 cm) and 19 inches (48 cm), respectively.

Note: An old news report describes an interesting hybrid between pig breeds. It resembled one breed with respect to the anterior portion of its body, while closely resembling the other with respect to its posterior. The report appeared in the Crawfordsville, Indiana, Review (May 26, 1894, p. 8, cols. 5 & 6):

There is a freak of nature at the stock yards in the shape of a hog. The head and front quarters are of the black Berkshire breed, while the remainder of the porker is that of a Poland China. Immediately behind the shoulders and extending around the entire body is a deep ridge fully three inches in depth which almost divides the front from the hindquarters of the hog and which at the same time divides the two different breeds of the animal. It is the strangest freak ever seen at the stock yards. The front quarters do not resemble the hindquarters in any particular, the hair being of a different quality as well as entirely different in color. It is a pet animal and very gentle. It is owned by Rabenstein & Harris, the commission merchants. It is visited daily by numerous sightseers. Cin. Enquirer.

Sus scrofa [Domestic Pig]
See also: Babyrousa babyrussa; Potamochoerus larvatus; P. porcus; Phacochoerus africanus; Sus barbatus; S. cebifrons; S. celebensis; S. oliveri; S. papuensis; S. philippensis. Also see the separate article entitled "Human Origins: Are we hybrids?"
× Bos taurus [European Domestic Cattle] See the separate article "Cow-pig Hybrids."
×Camelus dromedarius [Dromedary] Giambattista della Porta (Natural Magick, p. 41), the Renaissance scholar, polymath and playwright, citing Didymus Chalcenterus (c. 63 BC – c. AD 10), claimed that Bactrian camels were originally produced by hybridizing boars with dromedaries. There seems to be no modern evidence that such a cross is possible, so Porta's assertion is included here only as a historical note.
× Canis familiaris [Domestic Dog] See the separate article "Dog-pig Hybrids."
× Capra hircus [Domestic Goat] See the separate article "Cow-pig Hybrids."
× Equus caballus [Domestic Horse] See the separate article "Pig-horse Hybrids."
× Homo sapiens [Human] See the separate article "Pig-human Hybrids."
× Ovis aries [Domestic Sheep] See the separate article "Pig-sheep Hybrids."
× Sus verrucosus [Javan Pig] NHR(Indonesia). A probable hybrid was killed in 1982 in East Java (about 150 km southeast of Surabaya). Blouch and Groves mention two other unconfirmed reports of wild hybrids in East Java. Blouch and Groves 1990.
× Ursus americanus [Black Bear] See the separate article "A Bear-pig Hybrid?".

Sus timoriensis [Timor Wild Boar] See: Sus celebensis × S. scrofa.

Sus verrucosus [Javan Pig] See: Sus scrofa.

Table of contents >>

Bibliography >>

Biology Dictionary >>

By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).


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