|Subtribes and genera|
The tribe Bovini, or wild cattle, are medium to massive bovines that are native to North America, Eurasia, and Africa. These include the enigmatic, antelope-like saola, the African and Asiatic buffalos, and a clade that consists of bison and the wild cattle of the genus Bos. Not only are they the largest members of the subfamily Bovinae, they are the largest species of their family Bovidae. The largest species is the gaur (Bos gaurus), weighing up to 1,500 kg (3,300 lb).
Bovins and humans have had a long and complex relationship. Five of seven species have been successfully domesticated, with one species (cattle) being the most successful member of their lineage. Domesticated shortly after the last ice age, there are at least 1.4 billion cattle in the world. Domestic bovins have been selectively bred for beef, dairy products and leather, and serve as working animals. However, many species of wild cattle are threatened by extinction due to habitat loss to make room for cattle farming as well as unregulated hunting. Some are already extinct like the aurochs, two subspecies of European bison and perhaps the kouprey.
In 1821 British zoologist John Edward Gray described the family, subfamily and tribe Bovidae, Bovinae, and Bovini respectively. The word "Bovini" is the combination of the Latin prefix bos (written as bov-, which is Late Latin from bovinus) and the suffix -ini refers to their ranking as a tribe.
Placement within Bovinae
|Phylogenetic relationships of the Bovinae (Bibi et al., 2013)|
The wild cattle belong to the subfamily Bovinae, which also includes spiral-horned antelope of the tribe Tragelaphini and two aberrant species of Asian antelope, four-horned antelope and nilgai, which belong to the tribe Boselaphini. The relationship between the tribes varies in research concerning their phylogeny. Most molecular research supports a Bovini and Tragelaphini subclade of Bovinae. There are also some morphological support for this, most notably both groups have horn cores with a pedicle.
The fossil record
The earliest known wild cattle originated from Asia south of the Himalayas during the Late Miocene. This is not only supported by the fossil record but also the fact that south Asia has the highest diversity of wild cattle on planet, as well as the fact the southeast Asian saola is the basal most of the living species. At some point after the divergence of the three subtribes around 13.7 million years ago, bovins migrated into Africa from Asia where they have diversified into many species. During the Pliocene epoch some bovins left Africa and entered Europe, where they have evolved into hardy, cold-adapted species. During the Ice Age ancestors of the bison had colonized North America from Eurasia over the Bering Land Bridge in two waves, the first being 135,000 to 195,000 years ago and the second being 21,000 to 45,000 years ago.
Below is the list of fossil species that have been described so far listed in alphabetical order that currently do not fit in any of the existing subtribes:
- Tribe Bovini (Gray, 1821)
- Genus †Alephis (Gromolard, 1980)
- †Alephis lyrix (Gromolard, 1980)
- †Alephis tigneresi (Michaux et al., 1991)
- Genus †Eosyncerus (Vekua, 1972)
- †Eosyncerus ivericus (Vekua, 1972)
- Genus †Jamous (Geraads et al., 2008)
- †Jamous kolleensis (Geraads et al., 2008)
- Genus †Probison (Sahni & Khan, 1968)
- †Probison dehmi (Sahni & Khan, 1968)
- Genus †Simatherium (Dietrich, 1941)
- †Simatherium kohllarseni (Dietrich, 1941)
- †Simatherium shungurense (Geraads, 1995)
- Genus †Udabnocerus (Burchak-Abramovich & Gabashvili, 1969)
- †Udabnocerus georgicus (Burchak-Abramovich & Gabashvili, 1969)
- Genus †Alephis (Gromolard, 1980)
|Phylogenetic relationships of the tribe Bovini (Hassanin et al., 2013)|
Majority of phylogenetic work based on ribosomal DNA, chromosomal analysis, autosomal introns and mitochondrial DNA has recovered three distinctive subtribes of Bovini: Pseudorygina (represented solely by the saola), Bubalina (represented today by the genera Syncerus and Bubalus), and Bovina (represented today by the genera Bison and Bos). According to the fossil record and the molecular work, Bubalina and Bovina have diverged from one and another from a common ancestor around 13.7 million years ago in the Late Miocene.
The number of taxa and their evolutionary relationships with each other has been debated, mainly as there is several evidence of ancient hybridization events that occurred among the various species of wild cattle, obstructing any evidence of their relationships.
Below is the taxonomy of extant genera that are classified as members of the tribe Bovini (more information regarding the species taxonomy is explained more in-depth in their respective subtribe articles):
- Tribe Bovini (Gray, 1821)
- Subtribe Pseudorygina (Hassanin & Douzery, 1999)
- Subtribe Bubalina (Rütimeyer, 1865)
- Subtribe Bovina (Gray, 1821)
Wild cattle are usually massive bovids that are stout-bodied with thick, short legs. Some species can reach impressive body-sizes such as wild water buffalo, wild yak, American bison, and European bison, which can weigh between 700 and 1,200 kilograms and these species can attain a shoulder height more than 1.9 meters. The gaur can weigh up to 1,500 kilograms and attain a shoulder height up to 2.2 meters. There are some breeds of domestic cattle that can be even larger than both wild species, one of them being the Chianina, bulls of which can weigh from 1,200 to 1,500 kilograms and reach a similar height to the gaur. There are, however, several species of buffalo that live on the various islands in Indonesia are dwarf species, such as the tamaraw and the anoa, that weigh between 200 and 300 kilograms. Furthermore, not all species of bovin look like cattle, such as the saola which looks more like antelope (a fact that caused some confusion among bovid biologists). What all bovins or wild cattle do have in common is both sexes have the presence of smooth horns, instead of annulated horns seen in most other bovids. In bovinans the horns are round, while in bubalinans they are flattened. Like the spiral-horned antelopes there is extreme sexual dimorphism in bovins, though it is emphasis on the body size and the size of the horns. Males are significantly larger than the females, which most of their features are exaggerated with massive humps, large necks, and in some species the presence of a dewlap. Males and females exhibit sexual monochromatism (with the exception of the banteng, where males are a dark chestnut while females are just chestnut), though the male coloration hues are darker than the females. Coloration can be uniform or with some white markings, from black to brown.
Distribution and ecology
The wild species of bovins are found in North America, Eurasia and sub-Saharan Africa, though domesticated species or variants have a global cosmopolitan range with the help of humans. With the exception of the open-plains dwelling American bison and the montane-dwelling wild yak, all species of wild cattle inhabit wooded or forested areas with some clearings. The reason is that most species require much roughage (often tall grass) in their diet and much water to drink. In addition they are less efficient eaters than smaller herbivores, as they cannot selectively forage on relatively short grass due their stiff, immobile upperlips. They commonly wallow in mud and water in swamps, especially with water buffalo. Forest-dwelling live in deciduous and tropical forests. With their large body-size, wild cattle have few natural predators aside from humans. Still they are often prey to crocodiles, big cats, spotted hyenas, dholes, and wolves. It is often the young and the weak that are commonly selected by these predators.
Behavior and reproduction
Wild cattle are very social animals, which they accumulate into large herds, with some individual sizes that can go into the hundreds. Usually these herds consisted of females and their young, although in some species there are occasionally bachelor males among them. Generally the larger and more experienced males tend to be solitary, though in the breeding season mixed-herds occur. There is a strict hierarchy among males based on size dominance.
All species of bovin are polyandrous. During the rutting period males engage in ramming against each other in order to obtain the breeding rights for females as well as territory. The gestation period occurs once the female has been inseminated from the male successfully. In most species it lasts approximately nine to ten months. They only give birth to a single calf. Once the young are born, they won't wean until they are around six to 10 months depending on the species. Females of most species sexually mature by four years while for males it is seven years.
Genetics and hybridization
The chromosome number varies by species, and sometimes even by subspecies, which warrants further research for taxonomic purposes. The ancestral Y chromosome was probably a small acrocentric, but evolved into several distinct characteristics. The subtribe Bubalina have the acquisition of X-specific repetitive DNA sequence on their Y chromosomes; Bos has derivative metacentric Y chromosomes, and share the presence of shared derivative submetacentric X chromosomes with Bison. Below is a listing of the diploid number 2n of selected species as follows:
- Saola: 2n = 50
- Forest buffalo: 2n = 54
- Cape buffalo: 2n = 52
- Lowland anoa: 2n = 48
- Water buffalo: 2n = 48
- Gaur: 2n = 58
- Banteng: 2n = 60
- Yak: 2n = 60
- European bison: 2n = 60
- American bison: 2n = 60
- Cattle: 2n = 60
Bovin hybridization is most common in the subtribe Bovina, the most well known of these is the beefalo (a cross between cattle and American bison). Most of these hybrids are deliberate from humans wanting to improve the quality of various cattle breeds (in particular for beef production). All bovinan hybrids produce sterile males and fertile females following Haldane's rule. In addition for the agricultural purposes, bovin hybridization was used in the past to save several species such as the American bison in the past. This has caused problems for wild cattle conservation as hybrids pollute the genetic diversity of genetically-pure animals. Bovin hybridization was also a major factor behind the evolution of Bovini, as some species have evidence of ancient hybridization in their genome.
- Kingdon, J. (2015). The Kingdon Field Guide to African Mammals. Princeton University Press.
- Hassanin, A.; Ropiquet, A. (2004). "Molecular phylogeny of the tribe Bovini (Bovidae, Bovinae) and the taxonomic status of the Kouprey, Bos sauveli Urbain 1937". Molecular Phylogenetics and Evolution. 33 (3): 896–907. doi:10.1016/j.ympev.2004.08.009. PMID 15522811.[dead link]
- Bibi, F. (2013). "Phylogenetic relationships in the subfamily Bovinae (Mammalia: Artiodactyla) based on ribosomal DNA". BMC Evolutionary Biology. 13 (166): 166. doi:10.1186/1471-2148-13-166. PMC 3751017. PMID 23927069.
- Hassanin, A.; An, J.; Ropiquet, A.; Nguyen, T. T.; Couloux, A. (2013). "Combining multiple autosomal introns for studying shallow phylogeny and taxonomy of Laurasiatherian mammals: Application to the tribe Bovini (Cetartiodactyla, Bovidae)". Molecular Phylogenetics and Evolution. 63 (3): 766–775. doi:10.1016/j.ympev.2012.11.003. PMID 23159894.
- Hassanin, A. (2015). "Systematics and Phylogeny of Cattle". In Garrick, D.; Ruvinsky, A. (eds.). The Genetics of Cattle (Second ed.). Oxfordshire, Boston: Cabi. pp. 1–18. ISBN 9781780642215.
- Bollongino, R.; Burger, J.; Powell, A.; Mashkour, M.; Vigne, J.-D.; Thomas, M. G. (2012). "Modern taurine cattle descended from small number of Near-Eastern founders". Molecular Biology and Evolution. 29 (9): 2101–2104. doi:10.1093/molbev/mss092. PMID 22422765. Op. cit. in Wilkins, Alasdair (28 March 2012). "DNA reveals that cows were almost impossible to domesticate". io9. Retrieved 2 April 2012.
- "Counting Chickens". The Economist. 27 July 2011. Retrieved 6 July 2016.
- Castelló, J. R. (2016). Bovids of the Word. Princeton University Press.
- Timmins, R.J.; Burton, J.; Hedges, S. (2016). "Bos sauveli". IUCN Red List of Threatened Species. 2016: e.T2890A46363360. doi:10.2305/IUCN.UK.2016-2.RLTS.T2890A46363360.en. Retrieved 12 November 2021. Database entry includes a brief justification of why this species is critically endangered.
- Grubb, P. (2005). "Family Bovidae". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 637–722. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Marcot, J. D. (2007). "Molecular Phylogeny of Terrestrial Aritiodactyls: Conflicts and Resolutions". In Prothero, D. R.; Foss, S. E. (eds.). The Evolution of Artiodactyls. The Johns Hopkins University Press. pp. 4–18.
- Solounias, N. (2007). "Family Bovidae". In Prothero, D.R.; Foss, S. E. (eds.). The Evolution of Artiodactyls. The Johns Hopkins University Press. pp. 278–291.
- Bibi, F. (2007). "Origin, paleoecology, and paleobiogeography of early Bovini". Palaeogeography, Palaeoclimatology, Palaeoecology. 248 (1): 60–72. Bibcode:2007PPP...248...60B. doi:10.1016/j.palaeo.2006.11.009.
- Bibi, F. (2009). "The fossil record and evolution of Bovidae" (PDF). Palaeontologia Electronica. 12 (3): 1–11.
- Hassanin, A. (2014). "Systematic and evolution of Bovini". In Melletti, D. R.; Burton, J. (eds.). Ecology, Evolution and Behaviour of Wild Cattle: Implications for Conservation. Cambridge University Press. pp. 7–20.
- Bienvenido Martínez-Navarro, Juan Antonio Pérez-Claros, Maria Rita Palombo, Lorenzo Rook, and Paul Palmqvist: "The Olduvai buffalo Pelorovis and the origin of Bos". Quaternary Research Volume 68, Issue 2, September 2007, Pages 220–226. online
- Haile-Selassie, Yohannes; Vrba, Elizabeth S.; Bibi, Faysal (2009). "Bovidae". In Haile-Selassie, Yohannes; WoldeGabriel, Giday (eds.). Ardipithecus Kadabba: Late Miocene Evidence from the Middle Awash, Ethiopia. University of California Press. p. 295. ISBN 978-0-520-25440-4.
- An Alaska volcano and DNA reveal the timing of bison's arrival in North America, Alaska Dispatch News, Yereth Rosen, March 27, 2017. Retrieved 28 March 2017.
- Fossil and genomic evidence constrains the timing of bison arrival in North America, Proceedings of the National Academy of Sciences of the United States of America, Duane Froese et al, December 20, 2017. Retrieved 28 March 2017.
- Tanaka, K.; Solis, C. D.; Masangkay, J. S.; Maeda, K. L.; Kawamoto, Y.; Namikawa, T. (1996). "Phylogenetic relationship among all living species of the genus Bubalus based on DNA sequences of the cytochrome b gene". Biochemical Genetics. 34 (11): 443–452. doi:10.1007/bf00570125. PMID 9126673. S2CID 22075565.
- Hassanin, A.; Douzery, E. J. P. (1999). "Evolutionary affinities of the enigmatic saola (Pseudoryx nghetinhensis) in the context of the molecular phylogeny of Bovidae". Proceedings of the Royal Society B: Biological Sciences. 266 (1422): 893–900. doi:10.1098/rspb.1999.0720. PMC 1689916. PMID 10380679.
- Maceachern, S.; McEwan, J.; Goddard, M. (2009). "Phylogenetic reconstruction and the identification of ancient polymorphism in the Bovini tribe (Bovidae, Bovinae)". BMC Genomics. 10 (1): 177. doi:10.1186/1471-2164-10-177. PMC 2694835. PMID 19393045.
- Lenstra, J. A.; Bradley, D. G. (1999). "Systematics and phylogeny of cattle". The Genetics of Cattle: 1–14.
- Wilson, W. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference. The Johns Hopkins University Press.
- Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. The Johns Hopkins University Press.
- Estes, R. D. (1991). The Behaviour Guide to African Mammals: Including Hoofed Mammals, Carnivores, Primates. Johannesburg: Russell Friedman Books CC.
- Prothero, D. R. (2002). Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals. Johns Hopkins University Press.
- Chianina (in Italian). Atlante delle razze bovine – Razze da carne. Accessed November 2017.
- Daniele Bigi, Alessio Zanon (2008). Atlante delle razze autoctone: Bovini, equini, ovicaprini, suini allevati in Italia (in Italian). Milan: Edagricole. ISBN 9788850652594. p. 18–20.
- Gallagher, D. S.; Davis, S. K.; De Donato, M.; Burzlaff, J.D.; Womack, J. E.; Taylor, J. F.; Kumamoto, A. T. (1999). "A Molecular Cytogenetic Analysis of the Tribe Bovini (Artiodactyla: Bovidae: Bovinae) with an Emphasis on Sex Shromosome Morphology and NOR Distribution". Chromosome Research. 7 (6): 481–492. doi:10.1023/A:1009254014526. PMID 10560971. S2CID 12293611.
- Nguyen, T. T.; Aniskin, V. M.; Gerbault-Seureau, M.; Planton, J. P.; Renard, B. X.; Nguyen, A.; Hassanin, A.; Volobouev, V. T. (2008). "Phylogenetic position of the saola (Pseudoryx nghetinhensis) inferred from cytogenetic analysis of eleven species of Bovidae". Cytogenetic and Genome Research. 122 (1): 41–54. doi:10.1159/000151315. PMID 18931485. S2CID 20910793.
- Staff (November 7, 2017). "Restoring a Prairie Icon". National Wildlife. 50 (1): 20–25.
- Soubrier, J.; Gower, G.; Chen, K.; Richards, S. M.; Llamas, B.; Mitchell, K. J.; Ho, S. Y. W.; Kosintsev, P.; Lee, M. S. Y.; Baryshnikov, G.; Bollongino, R.; Bover, P.; Burger, J.; Chivall, D.; Crégut-Bonnoure, E.; Decker, J. E.; Doronichev, V. B.; Douka, K.; Fordham, D. A.; Fontana, F.; Fritz, C.; Glimmerveen, J.; Golovanova, L. V.; Groves, C.; Guerreschi, A.; Haak, W.; Higham, T.; Hofman-Kamińska, E.; Immel, A.; Julien, M.-A.; Krause, J.; Krotova, O.; Langbein, F.; Larson, G.; Rohrlach, A.; Scheu, A.; Schnabel, R. D.; Taylor, J. F.; Tokarska, M.; Tosello, G.; van der Plicht, J.; van Loenen, A.; Vigne, J.-D.; Wooley, O.; Orlando, L.; Kowalczyk, R.; Shapiro, B.; Cooper, A. (18 October 2016). "Early cave art and ancient DNA record the origin of European bison". Nature Communications. 7 (13158): 13158. Bibcode:2016NatCo...713158S. doi:10.1038/ncomms13158. PMC 5071849. PMID 27754477.