Hyrax

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Hyraxes
Temporal range: Eocene–Recent 55.8–0 Ma
Rock hyrax (Procavia capensis).jpg
Rock hyrax (Procavia capensis)
Erongo, Namibia
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Placentalia
Superorder: Afrotheria
Clade: Paenungulata
Order: Hyracoidea
Huxley, 1869
Families

Hyraxes (from the Greek ὕραξ, hýrax, "shrewmouse"), also called dassies,[1][2] are small, thickset, herbivorous mammals in the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Typically, they measure between 30 and 70 cm (12 and 28 in) long and weigh between 2 and 5 kg (4.4 and 11 lb). They are also superficially similar to pikas or marmots, but surprisingly are more closely related to elephants and manatees.

Five extant species are recognised; the rock hyrax (Procavia capensis) and the yellow-spotted rock hyrax (Heterohyrax brucei), which both live on rock outcrops, including cliffs in Ethiopia[3] and isolated granite outcrops called kopjes in southern Africa,[4] the western tree hyrax (Dendrohyrax dorsalis), southern tree hyrax (D. arboreus), and eastern tree hyrax (D. validus).[5] Their distribution is limited to Africa, except for Procavia capensis which is also found in the Middle East.

Characteristics[edit]

Hyraxes retain or have re-developed a number of primitive mammalian characteristics; in particular, they have poorly developed internal temperature regulation,[6] for which they compensate by behavioural thermoregulation, such as huddling together and basking in the sun.

Unlike most other browsing and grazing animals, they do not use the incisors at the front of the jaw for slicing off leaves and grass; rather, they use the molar teeth at the side of the jaw. The two upper incisors are large and tusk-like, and grow continuously through life, similar to rodents. The four lower incisors are deeply grooved 'comb teeth'. A diastema occurs between the incisors and the cheek teeth. The dental formula for hyraxes is 1.0.4.32.0.4.3.

A hyrax showing the characteristic chewing/grunting behavior: Note the incisor tusks.

Although not ruminants, hyraxes have complex, multichambered stomachs that allow symbiotic bacteria to break down tough plant materials, but their overall ability to digest fibre is lower than that of the ungulates.[7] Their mandibular motions (see video) are deceptively similar to chewing cud,[8] but the hyrax is physically incapable of regurgitation[9][10] as in the even-toed ungulates and the merycism of some of the macropods. This behaviour is referred to in a passage in the Bible which describes hyraxes as “chewing the cud”.[11] This chewing behaviour may be a form of agonistic behaviour when the animal feels threatened.[12]

Hyraxes inhabit rocky terrain across sub-Saharan Africa and the Middle East. Their feet have rubbery pads with numerous sweat glands, which may help the animal maintain its grip when quickly moving up steep, rocky surfaces. Hyraxes have stumpy toes with hoof-like nails; there are four toes on each front foot and three on each back foot.[13] They also have efficient kidneys, retaining water so that they can better survive in arid environments.

Female hyraxes give birth to up to four young after a gestation period between seven and eight months, depending on the species. The young are weaned at one to five months of age, and reach sexual maturity at 16 to 17 months.

Hyraxes live in small family groups, with a single male that aggressively defends the territory from rivals. Where living space is abundant, the male may have sole access to multiple groups of females, each with their own range. The remaining males live solitary lives, often on the periphery of areas controlled by larger males, and mate only with younger females.[14]

Hyraxes have highly charged myoglobin, which has been inferred to reflect an aquatic ancestry.[15]

Similarities with Proboscidea and Sirenia[edit]

Hyraxes share several unusual characteristics with mammalian orders Proboscidea (elephants and their extinct relatives) and Sirenia (manatees and dugongs), which have resulted in their all being placed in the taxon Paenungulata. Male hyraxes lack a scrotum and their testicles remain tucked up in their abdominal cavity next to the kidneys,[16][17] the same as in elephants, manatees, and dugongs.[18] Female hyraxes have a pair of teats near their armpits (axilla), as well as four teats in their groin (inguinal area); elephants have a pair of teats near their axillae, and dugongs and manatees have a pair of teats, one located close to each of the front flippers.[19][20] The tusks of hyraxes develop from the incisor teeth as do the tusks of elephants; most mammalian tusks develop from the canines. Hyraxes, like elephants, have flattened nails on the tips of their digits, rather than curved, elongated claws which are usually seen on mammals.[21]

Evolution[edit]

Pachyhyrax championi, a large fossil hyrax from the Miocene of Rusinga, Kenya (Natural History Museum collection)

All modern hyraxes are members of the family Procaviidae (the only living family within Hyracoidea) and are found only in Africa and the Middle East. In the past, however, hyraxes were more diverse, and widespread. The order first appears in the fossil record at a site in the Middle East in the form of Dimaitherium, 37 million years ago.[22] For many millions of years, hyraxes, proboscideans, and other afrotherian mammals were the primary terrestrial herbivores in Africa, just as odd-toed ungulates were in North America.

Through the middle to late Eocene, many different species existed,[23] the largest of them weighing the same as a small horse and the smallest the size of a mouse. During the Miocene, however, competition from the newly developed bovids, which were very efficient grazers and browsers, displaced the hyraxes into marginal niches. Nevertheless, the order remained widespread and diverse as late as the end of the Pliocene (about two million years ago) with representatives throughout most of Africa, Europe, and Asia.

The descendants of the giant 'hyracoids' (common ancestors to the hyraxes, elephants, and sirenians) evolved in different ways. Some became smaller, and evolved to become the modern hyrax family. Others appear to have taken to the water (perhaps like the modern capybara), ultimately giving rise to the elephant family and perhaps also the sirenians. DNA evidence supports this hypothesis, and the small modern hyraxes share numerous features with elephants, such as toenails, excellent hearing, sensitive pads on their feet, small tusks, good memory, higher brain functions compared with other similar mammals, and the shape of some of their bones.[24]

Hyraxes are sometimes described as being the closest living relative of the elephant,[25] although whether this is so is disputed. Recent morphological- and molecular-based classifications reveal the sirenians to be the closest living relatives of elephants. While hyraxes are closely related, they form a taxonomic outgroup to the assemblage of elephants, sirenians, and the extinct orders Embrithopoda and Desmostylia.[26]

The extinct meridiungulate family Archaeohyracidae, consisting of four genera of notoungulate mammals known from the Paleocene through the Oligocene of South America,[27] is a group unrelated to the true hyraxes.

List of genera[edit]

Phylogeny of early hyracoids
Eutheria
Afrotheria
Hyracoidea

Seggeurius

Microhyrax

Saghatheriinae [A]

Bunohyrax

Pachyhyrax

Thyrohyrax

Selenohyrax

Saghatherium

Titanohyrax

Antilohyrax

Megalohyrax

Geniohyiinae

Geniohyus

Proboscidea (elephants)

Perissodactyla [B]

Phenacodontidae

A phylogeny of hyracoids known from the early Eocene through the middle Oligocene epoch.[28]
  1. ^ Modern day hyrax species (Procaviidae) may have evolved from smaller members of one of the Saghatheriinae.
  2. ^ The relationship of hyracoids and Perissodactlya is controversial, and not supported by molecular data.

Extant species[edit]

In the 2000s taxonomists reduced the number of recognized species of hyrax. In 1995 they recognized 11 species or more; as of 2013 only four are recognized, with the others now all considered as a subspecies of one of the recognized four. Over 50 subspecies and species are described, many of which are considered highly endangered.[29]


Hyracoidea
Procaviidae
  Dendrohyrax  

Southern tree hyrax, D. arboreus arboreus

Eastern tree hyrax, D. arboreus validus[5]


Western tree hyrax, D. dorsalis
 

(genus)
Heterohyrax

Yellow-spotted rock hyrax, H. brucei

 

(genus)

 
Procavia

Rock hyrax, P. capensis

(genus)
(family)
(order)

Human interactions[edit]

Local and indigenous names[edit]

In Hebrew שָּׁפָן (shafan)[30]

In Tigrinya: ጊሐ (gihè)[3]

Biblical references[edit]

Young hyrax on Mount Kenya

References are made to hyraxes in the Old Testament (Leviticus 11:5; Deuteronomy 14:7; Psalm 104:18; Proverbs 30:26). In Leviticus they are described as lacking a split hoof and therefore not being kosher. It also describes the hyrax as chewing its cud; this is technically inaccurate as the hyrax does not regurgitate its food to chew it again. The Hebrew phrase in question (מַעֲלֵה גֵרָה) means "bringing up cud". Some of the modern translations refer to them as rock hyraxes.[citation needed]

... hyraxes are creatures of little power, yet they make their home in the crags; ...

The words "rabbit", "hare", "coney" or "daman" appear as terms for the hyrax in some English translations of the Bible.[citation needed] Early English translators had no knowledge of the hyrax and therefore no name for them, though "badger" or "rock-badger" has also been used more recently in new translations, especially in "common language" translations such as the Common English Bible (2011).

"Spain"[edit]

One of the proposed etymologies for "Spain" is that it may be a derivation of the Phoenician I-Shpania, meaning "island of rabbits", "land of rabbits"; Roman coins struck in the region from the reign of Hadrian show a female figure with a rabbit at her feet,[31] and Strabo called it the "land of the rabbits".[32] The word in question (compare modern Hebrew Shafan) actually means "Hyrax", possibly due to Phoenicians confusing the two animals.[33]

See also[edit]

Notes[edit]

References[edit]

  1. ^ "Hyracoidea" in Grzimek's Animal Life Encyclopedia, Vol. 15: Mammals. Gale Publishing. Online version accessed April 2014.
  2. ^ "Dassie, n." Dictionary of South African English. Dictionary Unit for South African English, 2018. Web. 25 February 2019.
  3. ^ a b Aerts, Raf (2019). Forest and woodland vegetation in the highlands of Dogu'a Tembien. In: Nyssen J., Jacob, M., Frankl, A. (Eds.). Geo-trekking in Ethiopia's Tropical Mountains - The Dogu'a Tembien District. SpringerNature. ISBN 978-3-030-04954-6. Retrieved 18 June 2019.
  4. ^ Encyclopedia of Deserts
  5. ^ a b "Eastern Tree Hyrax". IUCN red list. International Union for Conservation of Nature and Natural Resources. Retrieved 17 December 2018.
  6. ^ Brown, Kelly Joanne (2003). "SEASONAL VARIATION IN THE THERMAL BIOLOGY OF THE ROCK HYRAX (PROCA VIA CAPENSIS)" (PDF). School of Botany and Zoology / University of KwaZulu-Natal.
  7. ^ von Engelhardt, W; Wolter, S; Lawrenz, H; Hemsley, J.A. (1978). "Production of methane in two non-ruminant herbivores". Comparative Biochemistry and Physiology A. 60 (3): 309–11. doi:10.1016/0300-9629(78)90254-2.
  8. ^ Hendrichs, Hubert (1966). "Vergleichende Untersuchung des Wiederkauverhaltens" [Comparative investigation of cud retainers]. Biologisches Zentralblatt (dissertation) (in German). 84 (6): 671–751. OCLC 251821046. All artiodactyl families and about 80% of the spp. were investigated. Chewing regurgitated fodder is an idle pastime as well as an instinct associated with appetite. Characteristic movements were analyzed for undisturbed samples of animals maintained on preserves. Group specific differences are reported in form, rhythm, frequency and side of chewing motion. The ungulate type is characterized as a specialization. The operation is described for the first time for the order Hyracoidea. On the basis of 12 spp. of the marsupial subfamily Macropodinae rumination is inferred for the whole category. Advantages of the process are debated[verification needed]
  9. ^ Björnhag, G.; Becker, G.; Buchholz, C.; W. von Engelhardt, W. (1994). "The gastrointestinal tract of the rock hyrax (Procavia habessinica). 1. Morphology and motility patterns of the tract". Comparative Biochemistry and Physiology A. 109 (3): 649–53. doi:10.1016/0300-9629(94)90205-4. PMID 8529006.
  10. ^ Sale, J. B. (1966). "Daily food consumption and mode of ingestion in the Hyrax". Journal of the East African Natural History Society. XXV (3): 219.
  11. ^ "Leviticus 11:5". Bible Gateway. Zondervan. Retrieved 8 April 2016.
  12. ^ Natan Slifkin (11 March 2004). "Chapter Six – Shafan the Hyrax" (PDF). The Camel, the Hare, and the Hyrax. Archived from the original (PDF) on 16 June 2012. Retrieved 25 April 2012.
  13. ^ "Hyrax". wildlife conservation. awf.org.[full citation needed]
  14. ^ Hoeck, Hendrik (1984). Macdonald, D. (ed.). The Encyclopedia of Mammals. New York: Facts on File. pp. 462–5. ISBN 978-0-87196-871-5.
  15. ^ "One Protein Shows Elephants and Moles Had Aquatic Ancestors".
  16. ^ Trevor Carnaby (1 January 2008). Beat about the Bush: Mammals. Jacana Media. p. 293. ISBN 978-1-77009-240-2.
  17. ^ Septimus Sisson (1914). The anatomy of the domestic animals. W.B. Saunders Company. p. 577.
  18. ^ Marshall Cavendish Corporation (1 September 2010). Mammal Anatomy: An Illustrated Guide. Marshall Cavendish. p. 63. ISBN 978-0-7614-7882-9.
  19. ^ "Dugong". Australian Government / Great Barrer Reef Marine Park Authority.
  20. ^ Schrichte, David. "Reproduction". Save the Manatee org.
  21. ^ "Picture of hyrax feet".[dead link]
  22. ^ Eugenie Barrow; Erik R. Seiffert; Elwyn L. Simons (2010). "A primitive hyracoid (Mammalia, Paenungulata) from the early Priabonian (Late Eocene) of Egypt". Journal of Systematic Palaeontology. 8 (2): 213–244. doi:10.1080/14772010903450407.
  23. ^ Prothero, Donald R. (2006). After the Dinosaurs: The Age of Mammals. Bloomington, Indiana: Indiana University Press. p. 132. ISBN 978-0-253-34733-6.
  24. ^ "Hyrax: The Little Brother of the Elephant". Wildlife on One. BBC TV.
  25. ^ "Hirax song is a menu for mating". The Economist. 15 January 2009. Retrieved 15 January 2009.
  26. ^ Asher, R.J.; Novacek, M.J.; Geisher, J.H. (2003). "Relationships of endemic African mammals and their fossil relatives based on morphological and molecular evidence". Journal of Mammalian Evolution. 10: 131–194. doi:10.1023/A:1025504124129.
  27. ^ McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8
  28. ^ Gheerbrant, E.; Donming, D.; Tassy, P. (2005). "Paenungulata (Sirenia, Proboscidea, Hyracoidea, and Relatives)". In Rose, Kenneth D.; Archibald, J. David (eds.). The Rise of Placental Mammals: Origins and relationships of the major extant clades. Baltimore: Johns Hopkins University Press. pp. 84–105. ISBN 978-0801880223.
  29. ^ Shoshani, J. (2005). Wilson, D.E.; Reeder, D.M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 87–89. ISBN 978-0-8018-8221-0. OCLC 62265494.
  30. ^ ""Shaphan" in Strong's Concordance".
  31. ^ Burke, Ulick Ralph (1895). A History of Spain from the Earliest Times to the Death of Ferdinand the Catholic, Volume 1. London: Longmans, Green & Co. p. 12.
  32. ^ Wikisource-logo.svg Herbermann, Charles, ed. (1913). "Spain" . Catholic Encyclopedia. New York: Robert Appleton Company.
  33. ^ "Rabbits, fish and mice, but no rock hyrax". Understanding Animal Research.

External links[edit]

  • Data related to Procaviidae at Wikispecies
  • Media related to Hyrax at Wikimedia Commons