Bluebuck

Bluebuck
Temporal range: Late Pleistocene–recent
↓
One of four existing bluebuck skins, Vienna Museum of Natural History

Extinct  (c. 1800)  (IUCN 3.1)[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Hippotraginae
Genus: Hippotragus
Species: † H. leucophaeus
Binomial name
Hippotragus leucophaeus
(Pallas, 1766)
Former range in red
Synonyms[2]

The bluebuck or blue antelope (Hippotragus leucophaeus), sometimes called blaubok, is an extinct species of antelope, the first large African mammal to disappear in historic times. It is related to the roan antelope and sable antelope, but slightly smaller than either. It lived in the southwestern coastal region of South Africa savannas, but was more widespread during the last glacial. It was probably a selective feeder, preferring high-quality grasses.

Europeans encountered the bluebuck in the 17th century, but it was already uncommon by then. European settlers hunted it avidly, despite its flesh being distasteful, while converting its habitat to agriculture. The bluebuck became extinct around 1800. Only four mounted specimens remain, in museums in Vienna, Stockholm, Paris, and Leiden, along with some bones and horns elsewhere. None of the museum specimens shows a blue colour, which may have derived from a mixture of black and yellow hairs.

Taxonomy

Illustration by Robert Jacob Gordon, late 1700s

The common name "bluebuck" or "blue antelope" is English for the original Afrikaans name "blaubok" or "blauwbok" (pronounced /\ˈblau̇ˌbäk\/). The name is the fusion of two words: blauw ("blue", from the Middle Dutch blā) and bok ("male antelope" or "male goat", from the Middle Dutch boc). The scientific name of the bluebuck is Hippotragus leucophaeus. The generic name Hippotragus means "he-goat" in Greek,[3] while the specific name leucophaeus is a compound of two Greek words: leukos ("white") and phaios ("dusky").[4]

In her 1967 book Der Blaubock Hippotragus leucophaeus ("The Bluebuck, Hippotragus leucophaeus"), German zoologist Erna Mohr pointed out that the 1719 account of the Cape of Good Hope published by traveller Peter Kolbe is the first publication dealing with the bluebuck. He added an illustration, which Mohr believed was based on memory and notes. Kolbe's account was apparently erroneous in many aspects, yet Mohr was positive that the described animal is a bluebuck.[5][6][7] The next to illustrate the bluebuck was Welsh naturalist Thomas Pennant, who added an account of the antelope, calling it the "blue goat", in his 1771 Synopsis of Quadrupeds on the basis of a skin from the Cape of Good Hope and purchased from Amsterdam.[8]

In 1778, a drawing by the Swiss-Dutch natural philosopher Jean-Nicolas-Sébastien Allamand found place in Histoire Naturelle;[9] however, he called the antelope tzeiran, the Siberian name for the goitered gazelle.[10] The illustration is widely believed to be based on the same animal that is the type specimen at the National Museum of Natural History, Leiden (Netherlands). This drawing has been republished a number of times; German naturalist Johann Christian Daniel von Schreber in 1785, by English naturalist George Shaw in 1801, by Mohr in 1967 and by Dutch zoologists A. M. Husson and Lipke Holthuis in 1969.[5] Another record of the bluebuck appears in the travel memoirs of French explorer François Levaillant, published in the 1780s. The bluebuck appears less frequently in later literature.[10]

Today five mounted skins of the bluebuck are in existence: one each in Leiden, Paris, Stockholm, Uppsala and Vienna.[11] The only other historical remains are a skull at the Hunterian Museum and a pair of horns at the Natural History Museum, London, though it has been suggested the skull may instead belong to a sable antelope. In addition, skeletal remains have been found in both archaeological and palaeontological contexts.[12]

Evolution

Based on studies of morphology, the bluebuck has historically been classified as either a distinct species or as a subspecies of roan antelope (H. equinus). In 1974, Richard G. Klein showed that the bluebuck and roan antelope occurred sympatrically on the coastal plain of the southwestern Cape from Oakhurst to Uniondale during the early Holocene, supporting their separate status.[12][13]

In 1996, an analysis of mitochondrial DNA extracted from the bluebuck specimen in Vienna showed that it is outside the clade containing the roan and sable antelopes. The study therefore concluded that the bluebuck is a distinct species, and not merely a subspecies of the roan antelope as was supposed. The cladogram below shows the position of the bluebuck among its relatives, following the 1996 analysis:[13]


Blesbok (Damaliscus pygargus phillipsi)

Bontebok (Damaliscus pygargus pygarus)



Hippotragus

Bluebuck (Hippotragus leucophaeus)

Roan antelope ((Hippotragus equinus)

Sable antelope (Hippotragus niger)





Description

Illustration of a male and female (background), Joseph Wolf, 1884

British zoologists Philip Sclater and Oldfield Thomas give a comprehensive description of the bluebuck in their Book of Antelopes (1894). According to this account, the tallest specimen is the one at Paris, a male that stands 45 centimetres (18 in) at the shoulder; the specimen at Vienna is the shortest, a female 40 centimetres (16 in) tall. The bluebuck was notably smaller than the roan and the sable antelopes.[10] According to zoologists Colin Groves and Peter Grubb, the bluebuck was the smallest in its genus.[14] Moreover, its horns were significantly shorter and thinner than those of the roan antelope.[10] A study of rock paintings in the Caledon river valley in southeast Africa concluded that they represent bluebuck; it was deduced that bluebuck had similar proportions as the reedbuck.[15] Adult bluebuck probably rarely exceeded 160 kg (350 lb).

The coat was a uniform bluish-grey, with a pale whitish belly and similar flanks. Its mane was not as developed as in these two roan and sable antelopes. The forehead was brown, darker than the face.[10] Kolbe described the bluebuck as strange and uniformly gray throughout, with a pale snout, a beard like a goat's, a short bushy tail, and divergent horns as slender as those of the east African oryx or the gemsbok. However, some of the details were in strong conflict with subsequent accounts; the beard was apparently an exaggeration of the short mane, and the description of the tail did not agree with observations from procured specimens. Pennant observed that the eyes have white patches below them, and the underbelly is white; the coat was a "fine blue" in living specimens, while it changed to "bluish grey, with a mixture of white" in dead animals. He made an interesting observation that the length of the bluebuck's hair and the morphology of its horns formed a link between antelopes and goat.[8] None of the four museum specimens shows any sheen of blue. The dark skin showing through the thinning fur of older animals, or the mix of black and yellow hairs, may have caused the blue colours described by several authors.

Head of the bluebuck (2, top middle) and other antelopes, 1890—1907

The specimen at Paris has the longest horns, measuring 21.5 inches (55 cm). The horns at the Hunterian Museum are spaced 3.85 metres (152 in) apart, and are nearly 20 inches (51 cm) long with a basal circumference of nearly 6 centimetres (2.4 in). Other points of difference between the bluebuck and its extant relatives include its shorter and blunter ears that are not tipped with black and a darker tail tuft.[10] Pennant gave the horn length as 20 inches (51 cm). He added that the horns, sharp and curving backward, consist of twenty rings. He went on to describe the ears as pointed and over 9 inches (23 cm) long, and the tail as 7 inches (18 cm) long with a 6 centimetres (2.4 in) long tuft.[8] The horns of the bluebuck appear to have hollow pedicels (bony structures from which horns emerge).[16]

The teeth were smaller than in the roan and the sable antelopes.[17]

The total length of the bluebuck was 250–300 cm (8.2–9.8 ft) for the male, and 230–280 cm (7.5–9.2 ft) for the female. The shoulder height was 100–120 cm (3.3–3.9 ft). The skull length was 396 mm (15.6 in). Horn length was 50–61 cm (20–24 in). It weighed 160 kg (350 lb).

Like most antelopes, the bluebuck had six teeth along the cheek in each half of the upper and lower jaws. These formed two distinct series, three premolars immediately followed by three molars. Its remains can be distinguished from those of the roan by smaller molars and premolars, and from the sable by larger premolars, and a higher ratio of premolar row length to molar row length.

It had a relatively long, strong neck with a very short, underdeveloped mane,[18] long white legs with dark bands on the anterior, and a long tail, up to the hock, with a dark, horse-like whisk. It had a long muzzle. Its ears were long and donkey-like, rufous and narrow-pointed, without the black tufts of hair found in the roan.

The long, scimitar-shaped horns inserted directly above the orbits, extending upwards at almost right angles to the skull, and then curving back gently, without any torsion, towards the shoulders.[19] These horns were heavily ridged, with 20-35 rings up to the tip of the horn, comparable to the roan (20-50 rings). Its horns were more lightly built than those of the roan and sable, though, and slightly transversely compressed to the inside. The back-curved horns reminded Jan van Riebeeck of the European ibex, and he called it the steinbok. It remains uncertain how long this name was used, or when it was changed to blaauwbok or bluebuck.

Its hair was short and glossy. Its forehead and the upper muzzle were brown, becoming lighter towards the cheeks and upper lips.

The bulls resembled the cows up to the age of three years, after which they became paler (almost white) and developed larger, more curved horns; the horns of the cows were more or less of the same length, although thinner and 10-20% smaller. The calves younger than two months were light tan, with no or very indistinct markings.

Habitat and distribution

Illustration of a bluebuck and a klipspringer from 1851

Endemic to South Africa, the historical range of the bluebuck was confined to the southwestern Cape.[1] A 2003 study estimated the expanse of the historic range of the bluebuck at 4,300 square kilometres (1,700 sq mi), mainly along the southern coast of South Africa.[20] Historical records give a rough estimate of its range. On 20 January 1774, Swedish naturalist Carl Peter Thunberg recorded a sighting in Tigerhoek, Mpumalanga. In March or April 1783, Le Valliant claimed having witnessed two specimens in Soetemelksvlei, Western Cape. Based on these notes, the range of the bluebuck was estimated to be limited within a triangular area in he Western Cape. bounded by Caledon to the west, Swellendam to the northeast and Bredasdorp to the south by a 2009 study.[21] The bluebuck frequented grasslands and shunned wooded areas and thickets.[21] In a 1976 study of fossils in the Southern Cape, palaeoanthropologist Richard Klein observed that the blue antelope showed similar habitat preferences as did the Cape buffalo and reedbuck.[22]

In 1974, Klein studied the fossils of Hippotragus species in South Africa. Most of these were found to represent the bluebuck and the roan antelope. The fossil record suggested that the bluebuck occurred in large numbers during the last glacial period (nearly 0.1 million year ago), and was commoner than sympatric antelopes. The bluebuck occurred in the Klaises River and the Nelson Bay Caves (near Plettenberg Bay) and Swartklip (to the west of the Hottentots Holland Mountains). Its range seemed to have widened as the Holocene began (nearly 20,000 years ago), extending westward up to the Eland Bay and eastward up to the Uniondale Rock Shelter (Albany). The roan antelope seems to have appeared in the Nelson Bay Cave following climatic changes. The bluebuck could adapt to more open habitats than could the roan antelope, a notable point of difference between these sympatric species. The causes of the drastic fall in bluebuck populations before the 15th and 16th centuries have not been investigated; competition with livestock and habitat deterioration could have been major factors in the bluebuck's depletion.[12]

The early travellers found the bluebuck only in rolling grasslands with extensive marshes and open areas with perennial tuft grasses and little hillside scrub. It was also at home at higher elevations, up to 2,400 m above sea level. It was susceptible to droughts, and water was a necessary habitat requirement.

When the Europeans settled in the Cape Colony in the 17th and 18th centuries, they found the bluebuck on the coastal plains of the southwestern Cape Province,[23] east of the Hottentots Holland mountains. Lieutenant W.J. St. John also recorded 'roans' of a bluish grey colour at Liebenbergsvlei (28º15’S, 28º29’E) near Bethlehem in the Free State Province on 28–29 July 1853, and it is now thought that he actually saw the last remnants of a relict population of bluebuck.

Researchers of the National Museum in Bloemfontein have found San (Bushman) rock paintings near Ficksburg and Golden Gate Highlands National Park,[24][25] while Pleistocene deposits (100 000 to 10 000 years ago) confirm its existence at Rose Cottage cave near Ladybrand.[26]

Behaviour and ecology

Head of the specimen in Vienna

The bluebuck formed groups each comprising as many as 20 individuals.[17]

Most of its activities took place during the day, especially early in the morning and late in the afternoon.

Bluebucks followed the conventional territorial system among the Hippotragini or 'horse antelopes': territorial bulls, herds of cows and calves, and bachelor herds which were kept segregated by the territorial bulls.

Bluebuck cows and calves lived in small to medium-sized herds of five to 20 individuals, but herds of 35 to 80 were not unusual. They normally occurred at a low density of about 4/km2. Cows shared a traditional home range, which included the territories of several bulls, and occupied it for up to 30 years. At very low densities in substandard habitats, the cows ranged across larger areas, and were accompanied by the same bull, which in the absence of resistance by territorial neighbours, defended a movable space around his own private harem.

Because they had long, dangerous horns, cows tended to be more aggressive than those antelopes whose females are hornless. Dominance hierarchies based on age and individual prowess were vigorously maintained by both sexes. Maternal herds, composed of animals with the same home range, were closed to outsiders. Herd members kept out of range of each other's horns, by increasing the individual space between them.

Herd composition changed daily and seasonally; members split into small groups during the rainy season, and concentrated into larger groups on the best available grazing near water during the dry season. The most cohesive groups were maintained by calves of different ages, which clustered around the youngest calf and usually lagged behind the herd.

Drawing of a bluebuck from 1778 by Allamand, based on the stuffed type specimen

Bulls were accepted in the natal herd up to the age of 15–18 months, which was unusually long. Until then, their similarity to cows suppressed the aggression of the territorial bulls. Subadult bulls were driven from the herd, and if they did not escape quickly enough, they were killed. They then joined bachelor herds, where they stayed until they reached five or six years of age, when they would be strong enough to defend their own territories.

The adult bull would advertise his presence and high social status by standing or lying alone or away from the herd, at a conspicuous place. The bull stood erect as a sign of high status, and it was self-advertising if it was not directed. When another bull approached his herd, the dominant bull would stand with his neck arched, head high, and ears turned sideways. Unless the intruder showed submission by lowering his head, the bull kept his ears erect, and waved his tail or tucked it between his legs, and a clash of horns and head-butting would take place. Its sound was a blowing snort.

Diet

Similarities to the roan and the sable antelopes in terms of dental morphology makes it highly probable that the bluebuck was predominantly a selective grazer.[27][20] Its diet comprised mainly grasses; the row of premolars was longer than in others of the genus, implying the presence dicots in the diet.[28]

Like the roan and sable, it had to drink daily. Many other antelopes can obtain the moisture they need from the plants they eat and can go for long periods without drinking.

The bluebuck fed on medium to long (0.5- to 1.5-m), perennial tuft grasses, such as high-quality red grass (Themeda triandra), spear grass (Heteropogon contortus), buffalo grass (Panicum spp.) and love grass (Eragrostis spp.). Unlike most other antelope, it was not particularly attracted to fresh grass, except during the dry season, when it would graze for short periods along drainage lines and on floodplains on the fresh growth following the yearly fires. However, like most grazers, it would probably browse during the dry season.

Reproduction

One calf, with a birth mass of 12–14 kg, was dropped after a gestation period of 268–281 days at any time of the year, with a peak during late summer. Bluebuck are thought to have lived for up to 18 years.

Predators

The calves were vulnerable to attacks from spotted hyenas (Crocuta crocuta), leopards (Panthera pardus) and wild dogs (Lycaon pictus). The adults were large and formidable, and resistant to predation in areas with low predator densities. They did sometimes fall prey to lions (Panthera leo), but were attacked with caution. Normally, they would flee from predators, but when wounded, a bluebuck would lie down, preferably in a marsh, and defended itself with its razor-sharp horns - the angle-horn threat display indicating it intended to stab sideways or over its shoulder.

Decline and extinction

Drawing from 1781, by Le Vaillant

Due to the small range of the bluebuck at the time of European settlement of the Cape region compared to the much wider area evidenced by fossil remains, it is thought the species was already in decline before this time. The bluebuck was the sole species of Hippotragus in the region until 70,000-35,000 years ago, but the roan antelope appears to have become predominant about 11,000 years ago. This may have coincided with grasslands being replaced by for example brush and forest, thereby reducing the presumably preferred habitat of the bluebuck.[13]

According to the International Union for the Conservation of Nature and Natural Resources (IUCN), the last bluebuck specimen was shot around 1800. The bluebuck is the first large African mammal to have faced extinction,[29][13] followed by the quagga that died out in the late 19th century.[30] The numbers of the bluebuck had already declined significantly and its range had contracted when Europeans who settled in the Cape Colony in the 17th and 18th centuries first came across this antelope. Around the time of its extinction, the bluebuck occurred what would be known as the Overberg region (Western Cape), probably concentrated in Swellendam.[31]

European hunters and farmers hunted it mainly for its skin. Its meat was not fatty, and generally fed to the dogs, although it was just as tasty as that of deer. According to German zoologist Martin Lichtenstein, the last bluebuck in the Cape Province was killed in 1799/1800 in the Swellendam district.[32] However,evidence suggests an isolated remnant population still existed further north in the 18th century, and the last bluebuck died in the eastern Free State more than 50 years later.

Cultivation of the Cape Colony and hunting with firearms quickly destroyed the last small herds. The bluebuck disappeared before the early natural history cabinets and museums had a chance to obtain a fair number of specimens.

See also

References

  1. 1 2 IUCN SSC Antelope Specialist Group (2008). Hippotragus leucophaeus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 5 January 2009.
  2. ↑ Wilson, D.E.; Reeder, D.M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 718. ISBN 978-0-8018-8221-0. OCLC 62265494.
  3. ↑ "Hippotragus". Merriam-Webster Dictionary. Retrieved 1 April 2016.
  4. ↑ Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names from Aalge to Zusii. London, UK: Christopher Helm. p. 224. ISBN 978-1408-133-262.
  5. 1 2 Husson, A.M.; Holthuis, L.B. (1975). "The earliest figures of the blaauwbok, Hippotragus leucophaeus (Pallas, 1766) and of the greater kudu, Tragelaphus strepsiceros (Pallas, 1766)". Zoologische Mededelingen 49 (5): 57–63. ISSN 0024-0672.
  6. ↑ Smithers, R.H.N. 1983. Die soogdiere van die Suider-Afrikaanse substreek. Universiteit van Pretoria, Pretoria.
  7. ↑ Stuart, C. & Stuart, T. 1996. Africa’s vanishing wildlife. Southern Book Publishers, Halfway House.
  8. 1 2 3 Pennant, T. (1771). Synopsis of Quadrupeds. London, UK: B. & J. White. p. 24.
  9. ↑ de Buffon, C. (1778). Histoire naturelle, générale et particulière. Servant de suite à l'histoire des animaux Quadrupèdes (Supplement 4). Amsterdam, Netherlands: Chez J.H. Schneider. pp. 151–3; one plate.
  10. 1 2 3 4 5 6 Sclater, P.; Thomas, O. (1899). The Book of Antelopes IV. London, UK: R. H. Porter. pp. 4–12.
  11. ↑ van Broggen, A.C. (1959). "Illustrated notes on some extinct South African ungulates" (PDF). South African Journal of Science: 197–200.
  12. 1 2 3 Klein, R.G. (1974). "On the taxonomic status, distribution and ecology of the blue antelope, Hippotragus leucophaeus". Annals of the South African Museum 65 (4): 99–143.
  13. 1 2 3 4 Robinson, T.J.; Bastos, A.D.; Halanych, K.M.; Herzig, B. (1996). "Mitochondrial DNA sequence relationships of the extinct blue antelope Hippotragus leucophaeus". Die Naturwissenschaften 83 (4): 178–82. PMID 8643125.
  14. ↑ Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. Baltimore, Maryland (USA): Johns Hopkins University Press. p. 198. ISBN 978-1421-400-938.
  15. ↑ Loubser, J.; Brink, J.; Laurens, G. (1990). "Paintings of the extinct blue antelope, Hippotragus leucophaeus, in the eastern Orange Free State". The South African Archaeological Bulletin 45 (152): 106–11. JSTOR 3887969.
  16. ↑ Vrba, E.S. (1987). "New species and a new genus of Hippotragini (Bovidae) from Makapansgat limeworks" (PDF). Palaentologica Africana 26 (5): 47–58.
  17. 1 2 Rookmaaker, L. (1992). "Additions and revisions to the list of specimens of the extinct blue antelope (Hippotragus leucophaeus)" (PDF). Annals of the South African Museum 102 (3): 131–41.
  18. ↑ Zaloumis, E.A. & Cross, R. 1987. A field guide to the antelope of Southern Africa. Natal Branch of the Wildlife Society of Southern Africa, Durban.
  19. ↑ Colahan, B.D. 1990. "Did the last blue antelope Hippotragus leucophaeus die in the Eastern Orange Free State, South Africa?" Mirafra 7 (2): 51-52.
  20. 1 2 Kerley, G.I.H.; Pressey, R.L.; Cowling, R.M.; Boshoff, A.F; Sims-Castley, R. (2003). "Options for the conservation of large and medium-sized mammals in the Cape Floristic Region hotspot, South Africa" (PDF). Biological Conservation 112 (1-2): 169–90. doi:10.1016/S0006-3207(02)00426-3.
  21. 1 2 Kerley, G.I.H.; Sims-Castley, R.; Boshoff, A.F.; Cowling, R.M. (2009). "Extinction of the blue antelope Hippotragus leucophaeus: modeling predicts non-viable global population size as the primary driver". Biodiversity and Conservation 18 (12): 3235–42. doi:10.1007/s10531-009-9639-x.
  22. ↑ Klein, R.G. (1976). "The mammalian fauna of the Klasies River mouth sites, Southern Cape Province, South Africa" (PDF). The South African Archaeological Bulletin 31 (123-4): 75–98. doi:10.2307/3887730.
  23. ↑ Comrie-Greig, J. 1992. Vrae en antwoorde - Bedreigde natuurlewe van Suider-Afrika. Struik Uitgewers, Kaapstad.
  24. ↑ Woodhouse, B. 1996. The rock art of the Golden Gate and Clarens districts. William Waterman Publications, Rivonia.
  25. ↑ Smith, M. 10 Januarie 2001. Boesmantekeninge van uitgestorwe kwagga gekry. Volksblad: 5.
  26. ↑ De la Harpe, R. 2002. Puik vakansieplekke in Suid-Afrika. Sunbird Publishing, Kaapstad.
  27. ↑ Stynder, D.D. (2009). "The diets of ungulates from the hominid fossil-bearing site of Elandsfontein, Western Cape, South Africa". Quaternary Research 71 (1): 62–70. doi:10.1016/j.yqres.2008.06.003.
  28. ↑ Faith, J.T.; Thompson, J.C.; McGeoch, M. (2013). "Fossil evidence for seasonal calving and migration of extinct blue antelope (Hippotragus leucophaeus) in southern Africa" (PDF). Journal of Biogeography 40 (11): 2108–18. doi:10.1111/jbi.12154.
  29. ↑ Dolan Jr., J. (1964). "Notes on Hippotragus niger roosevelti" (PDF). Zeitschrift Saugetierkundliche 29 (5): 309–12.
  30. ↑ IUCN SSC Antelope Specialist Group (2008). Equus quagga ssp. quagga. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 12 April 2016.
  31. ↑ Stuart, C.; Stuart, T. (2001). Field Guide to Mammals of Southern Africa (3rd ed.). Cape Town, South Africa: Struik Publishers. p. 14. ISBN 978-1-86872-537-3.
  32. ↑ Skead, C.J. 1987. Historical mammal incidence in the Cape Province. Volume 1 – The Western and Northern Cape. The Department of Nature and Environmental Conservation of the Provincial Administration of the Cape of Good Hope, Cape Town.

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