Giant eland
Giant eland | |
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T. d. derbianus Senegal | |
T. d. gigas at the Cincinnati Zoo
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Artiodactyla |
Family: | Bovidae |
Subfamily: | Bovinae |
Genus: | Taurotragus |
Species: | T. derbianus
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Binomial name | |
Taurotragus derbianus (J.E. Gray, 1847)
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Subspecies | |
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Distribution of giant eland subspecies: Western giant eland Eastern giant eland | |
Synonyms | |
Species synonymy[2]
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The giant eland (Taurotragus derbianus), also known as the Lord Derby's eland and greater eland, is an open-forest and savanna antelope. A species of the family Bovidae and genus Taurotragus, it was described in 1847 by John Edward Gray. The giant eland is the largest species of antelope, with a body length ranging from 220–290 cm (87–114 in). There are two subspecies: T. d. derbianus and T. d. gigas.
The giant eland is a herbivore, eating grasses, foliage and branches. They usually form small herds consisting of 15–25 members, both males and females. Giant elands are not territorial, and have large home ranges. They are naturally alert and wary, which makes them difficult to approach and observe. They can run at up to 70 km/h (43 mph) and use this speed as a defence against predators. Mating occurs throughout the year but peaks in the wet season. They mostly inhabit broad-leafed savannas, woodlands and glades.
The giant eland is native to Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Guinea, Mali, Senegal, and South Sudan. It is no longer present in The Gambia, Ghana, Ivory Coast, and Togo. It can also be found in the Jos wildlife park in Nigeria, Guinea-Bissau, and Uganda. The subspecies have been listed with different conservation statuses by the International Union for Conservation of Nature (IUCN).
Etymology
The scientific name of the giant eland is Taurotragus derbianus, derived from three words: tauros, tragos, and derbianus. Tauros is Greek for a bull or bullock.[3][4] Tragos is Greek for a male goat, and refers to the tuft of hair that grows in the eland's ear which resembles a goat's beard.[5]
The giant eland is also called "Lord Derby's eland" in honour of Edward Smith-Stanley, 13th Earl of Derby. It was due to his efforts that the giant eland was first introduced to England between 1835 and 1851. Lord Derby sent botanist Joseph Burke to collect animals, either alive or dead, from South Africa for his museum and menagerie. The first elands introduced in England were a pair of common elands, and what would later be identified as a giant eland bull.[6] The details were recorded in Smith-Stanley's privately printed work, Gleanings from the Menagerie at Knowsley Hall.[7] The Latin name indicates that it "belonged to" (given by the suffix -anus) Derby, hence derbianus.[8]
Although the giant eland is somewhat larger than the common eland, the epithet 'giant' actually refers to its large horns.[8][9] The name 'eland' is Dutch for "elk" or "moose". It has a Baltic source similar to the Lithuanian élnis, which means "deer". It was borrowed earlier as ellan (French) in the 1610s or elend (German).[10][11][12]
Taxonomy
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Phylogenetic relationships of the mountain nyala from combined analysis of all molecular data (Willows-Munro et.al. 2005) |
The giant eland was first described in 1847 by John Edward Gray, a British zoologist, who called it Boselaphus derbianus.[2] At that time, it was also called the 'black-necked eland' and Gingi-ganga.[13]
Giant eland is placed in the genus
Two subspecies of giant eland have been recognized:[1][15][16]
Image | Name | Distribution |
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T. d. derbianus J. E. Gray, 1847 – western giant eland | found in western Africa, particularly Senegal to Mali | |
T. d. gigas Heuglin, 1863 – eastern giant eland | found in central to eastern Africa, particularly Cameroon to South Sudan |
Description
The giant elands are spiral-horned antelopes. Despite its common name, this species broadly overlaps in size with the common eland (Taurotragus oryx). However, the giant eland is somewhat larger on average than the common eland and is thus the largest species of antelope in the world.[17][18][19][20] They are typically between 219 and 291 cm (7.19 and 9.55 ft) in head-and-body length and stand approximately 128 to 181 cm (4.20 to 5.94 ft) at the shoulder. Giant elands exhibit sexual dimorphism, as males are larger than females. The males weigh 400 to 1,200 kg (880 to 2,650 lb) and females weigh 300 to 600 kg (660 to 1,320 lb).[21] The tail is long, having a dark tuft of hair, and averages 91 cm (36 in) in length.[8] The life expectancy of giant elands is up to 25 years.[21]
The smooth
A crest of short black hair extends down the neck to the middle of the back, and is particularly prominent on the shoulders. The slender legs are slightly lighter on their inner surfaces, with black and white markings just above the
Both sexes have tightly spiraled, V-shaped horns.[25] They can be up to 124 cm (4.07 ft) long on males and 67 cm (2.20 ft) on females.[21] Males have horns that are thicker at the ends, longer, and more divergent than those of females.[9] These features of the horns suggest that the giant eland evolved from an ancestor with true display horns.[23]
Parasites
Fecal studies of the western giant eland revealed the presence of a newly found species
Genetics and evolution
The giant eland has 31 male
An accidental mating between a male giant eland and a female kudu produced a male offspring, but it was
Previous genetic studies of African savanna ungulates revealed the presence of a long-standing Pleistocene refugium in eastern and southern Africa, which also includes the giant eland. The common eland and giant eland have been estimated to have diverged about 1.6 million years ago.[30]
Habitat and distribution
Giant elands live in the broad-leafed savanna, woodlands, and glades of central and western Africa, which correspond to the two subspecies. They also live in forests as well as on the fringes of deserts. The giant elands can also live in deserts, as they produce very dry dung.[31] They are found in South Sudan and Central African Republic into northern Cameroon and southern Chad.[15]
They inhabit places near hilly or rocky landscapes and those with water sources nearby. Science author Jonathan Kingdon had thought the giant elands lived only in woodlands of Isoberlinia doka, an African hardwood tree.[1] The giant eland is adapted to these broad-leafed, deciduous Isoberlinia woodlands.[24] Recent studies proved that they also inhabit woodlands with trees of the genera Terminalia, Combretum, and Afzelia.[1]
In the past, giant elands occurred throughout the relatively narrow belt of savanna woodland that extends across West and Central Africa from Senegal to the Nile. Today they are conserved in national parks and reserves, and occur mostly in Senegal. The western giant eland is largely restricted to Niokolo-Koba National Park in Senegal. The eastern giant eland is found in several reserves, for example in Bénoué National Park, Faro National Park and Bouba Njida National Park in Cameroon and in Manovo-Gounda St. Floris National Park in the Central African Republic. They are also kept in captivity.[1]
Ecology and behaviour
Primarily
Giant elands are alert and wary, making them difficult to approach and observe or to hunt.[15][34] If a bull senses danger, he will give deep-throated barks while leaving the herd, repeating the process until the whole herd is aware of the danger. Giant elands can move quickly, running at over 70 km/h (43 mph), and despite their size are exceptional jumpers, easily clearing heights of 1.5 m (4.9 ft).[31] Their primary predators are the lion, nile crocodile and spotted hyena, while young, sickly and a rare adult may be vulnerable to leopards, cheetahs and African wild dogs.[8] Due to their large size, they prove a good meal for the predators.[15] However, they are not easily taken by any predator, especially the heavier and larger horned bulls which can be a dangerous adversary even for a lion pride.[35][36][37]
Diet
Primarily a herbivore, the giant eland eats grasses and foliage, as well as other parts of a plant.
As they need a regular intake of water in their diet, they prefer living in places with a nearby water source.[8] However, some adaptations they possess help them to survive even in the lack of water by maintaining a sufficient quantity of it in their body. They produce very dry dung compared to domestic cattle. In deserts, they can get their required water from the moisture of succulent plants. Another way in which they conserve water is by resting in the day and feeding at night, so that they minimize the water quantity required to cool themselves.[31]
Several studies have investigated the eland's diet. A study of giant elands in the Bandia Natural reserve in Senegal revealed that the most important and most preferred plants were various species of
In 2010, histological analysis of the feces of South African western giant elands was done in the Niokolo-Koba National Park and in the Bandia National Reserve. In both studies leaves, shoots of woody plants, and fruits were found to be the three major components. The other components that appeared in minor proportions were forbs and grasses, generally below five percent of the mean fecal volume. They were seen eating most foliage from Boscia angustifolia, Grewia bicolor, Hymenocardia acida, and Ziziphus mauritiana, and the fruits of Acacia and Strychnos spinosa. In the Bandia Reserve, differences in diet were marked among age classes. The conclusions were that in the dry season the eland was a pure browser, consuming grasses in small amounts.[39][40]
Reproduction
Mating occurs throughout the year, but peaks in the wet season. Females reach sexual maturity at about two years, and males at four to five years. A female can remain in
Fights occur for
After the courtship, the
A Senegalese study focused on the
Populations
The eastern giant eland ranged from Nigeria, through Cameroon, Chad, the Central African Republic, and the Democratic Republic of the Congo (formerly Zaire) to Sudan and Uganda in 1980.[44] But the rinderpest outbreak (1983–1984) caused a devastating 60–80% decline in the populations.[1] The eastern giant eland is still found in extensive areas, though it has a decreasing population trend. Because of this, it is listed as 'Vulnerable' by the IUCN. It has many uninhabited habitats that are not expected to be occupied for human settlement, particularly in northern and eastern Central African Republic and south-western Sudan, where their population has notably increased.[44] According to Rod East, 15,000 eastern giant elands existed as of 1999, of which 12,500 are in Central African Republic. The remaining areas are often disturbed by wars and conflicts—activities that can lead to a rapid decline in the eastern giant eland's numbers if not controlled.[1]
The western giant eland is in a more dangerous situation, being listed as 'Critically Endangered' by the IUCN. Today they mostly occur in Senegal. In 1990, populations were about 1000, of which 700 to 800 were found in the Niokolo-Koba National Park and the rest in the region around the Falémé River.[15][44] As of 2008, a population of less than 200 individuals occur there, and only a few elands exist in neighboring countries.[1]
A study of the long-term conservation strategy of the western giant eland was done in the Bandia and Fathala reserves, using demographic and pedigree data based on continuous monitoring of reproduction during 2000 to 2009. In 2009, the semi-captive population was 54 individuals (26 males, 28 females). The female breeding probability was 84%, and the annual population growth was 1.36. With more population, the elands were divided into five groups for observation. Although the mean interbreeding level became 0.119, a potential gene diversity (GD) of 92% was retained. The authors concluded that with the introduction of new founders, the GD could be greatly improved in the next 100 years, and suggested that with proper management of the semi-captive population, the numbers of the western giant eland could be increased.[45]
Interaction with humans
Threats and conservation
The major threats to the western giant eland population are overhunting for its rich meat and habitat destruction caused by the expansion of human and livestock populations.[1] The eastern giant eland is also depleting for similar reasons, and natural causes like continued droughts and competition from domestic animals are contributing to the reduction in numbers. Populations of the eastern giant eland had already gone down due to the rinderpest attacks. The situation was worse during World War II and other civil wars and political conflicts that harmed their natural habitats.[15]
The giant eland is already extirpated in The Gambia, Ghana, Ivory Coast, and Togo. The western giant eland was once reported in Togo, but is believed to have been confused with the bongo (Tragalephaus eurycerus).[1] In 1970, it was reported eliminated in Uganda, during military operations.[23] Its presence is uncertain in Guinea-Bissau[46] and Nigeria.[1]
Today the western giant eland is conserved in the Niokolo-Koba National Park and the Faheme Hunting Zone in Senegal. Field studies have proved that the Niokolo-Koba National Park is ecologically suitable for the giant eland. As observed in the 2000 census of the park, the number of deaths in a decade were only 90 to 150.[47]
The eastern giant eland is conserved in the
Uses
Giant elands give large quantities of tender meat and high-quality hides even if fed a low-quality diet. These are game animals and are also hunted for trophies. Their milk is comparatively richer in
Many people prefer to tame and raise eland rather than cattle due to their numerous benefits. Elands can survive on scarce water, which is a great advantage over domestic cattle. They can also eat coarse grasses, and can even manage to ingest some poisonous plants that can prove fatal for cattle. They are also immune to some diseases to which cattle may succumb.[31]
References
- ^ . Retrieved 12 January 2018. Database entry includes a brief justification of why this species is of vulnerable.
- ^ OCLC 62265494.
- ^ "Taurus". Encyclopædia Britannica. Merriam-Webster. Retrieved 29 July 2012.
- ^ Harper, Douglas. "Taurus". Online Etymology Dictionary. Retrieved 29 July 2012.
- ^ "Tragos". Online Etymology Dictionary. Retrieved 29 July 2012.
- doi:10.7202/030791ar.
- ^ Cook, John Douglas; Harwood, Philip; Pollock, Walter Herries; Harris, Frank; Hodge, Harold (February 12, 1859). "The New Venison". The Saturday Review of Politics, Literature, Science and Art. Vol. 7. John W Parker and Sons. p. 183.
- ^ a b c d e f g h Huffman, B. "Giant eland, Derby eland". Ultimate Ungulate. Archived from the original on 11 September 2012. Retrieved 29 July 2012.
- ^ ISBN 978-1-4214-0093-8.
- ^ "Eland". Oxford Dictionaries. Oxford University Press. Retrieved 29 July 2012.[dead link]
- ^ "Eland". Encyclopædia Britannica. Merriam-Webster. Retrieved 29 July 2012.
- ^ Douglas, Harper. "Eland". Online Etymology Dictionary. Retrieved 7 August 2012.
- .
- S2CID 198968884. Archived from the original(PDF) on 2011-12-23.
- ^ ISBN 978-0-7614-7198-1.
- ISBN 978-2-8317-0477-7.
- ^ a b c "Ecology". Czech University of Life Sciences. Giant eland conservation. Retrieved 29 July 2012.
- ISBN 978-0-8018-7135-1.
- ISBN 978-1-86872-921-0.
- ISBN 978-1-4027-5623-8.
- ^ a b c d e f g Atlan, B. "Taurotragus derbianus". University of Michigan Museum of Zoology. Animal Diversity Web. Retrieved 29 July 2012.
- ^ a b "Biological characteristics". Czech University of Life Sciences. Giant eland conservation. Retrieved 29 July 2012.
- ^ ISBN 978-0-226-43724-8.
- ^ ISBN 978-0-520-08085-0.
- ^ a b c "Western giant eland". Animal Planet. Archived from the original on 18 February 2011. Retrieved 29 July 2012.
- S2CID 7960679.
- ^ "Taurotragus derbianus". Myers Enterprises. Global Species. Archived from the original on 24 February 2015. Retrieved 29 July 2012.
- S2CID 23066105.
- PMID 944778.
- S2CID 85986567.
- ^ ISBN 978-0-7614-7266-7.
- ISBN 978-0-9805048-0-4.
- .
- ISBN 978-2-8317-0016-8.
- ^ Angwafo, T. E. (2006). Status of Wildlife and its Utilisation in Faro and Benoué National Parks North Cameroon: Case study of the Derby Eland (Taurotragus derbianus gigas Gray, 1947) and the African Wild Dog (Lycaon pictus Temminck, 1840) (Doctoral dissertation, Universitätsbibliothek).
- ^ Silvestre, I., Novelli, O., & Bogliani, G. (2000). Feeding habits of the spotted hyaena in the Niokolo Koba National Park, Senegal. African Journal of Ecology, 38(2), 102-107.
- ^ Ruggiero, R. G. (1991). Prey selection of the lion (Panthera leo L.) in the Manovo-Gounda-St. Floris National Park, Central African Republic. Mammalia, 55(1), 23-34.
- .
- ISBN 978-1-4649-6576-0.
- S2CID 84533849.
- ^ ISBN 978-0-8018-5789-8.
- ^ ISBN 978-1-890132-44-6.
- S2CID 26067910.
- ^ a b c "Status". Czech University of Life Sciences, Institute of Tropics and Subtropics. Giant Eland Conservation. Retrieved 29 July 2012.
- S2CID 84816996.
- ISBN 978-2-8317-0016-8.)
{{cite book}}
: CS1 maint: others (link - ISSN 0231-5742.
- ^ "Eastern Giant Eland". Archived from the original on 4 May 2013. Retrieved 21 June 2013.
External links
- Information at ITIS