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African clawless otter

The African clawless otter (Aonyx capensis), also known as the Cape clawless otter or groot otter, is the second-largest freshwater otter species. It inhabits permanent water bodies in savannah and lowland forest areas through most of sub-Saharan Africa.[2] It is characterised by partly webbed and clawless feet, from which their name is derived. The word 'aonyx' means clawless, derived from the prefix a- ("without") and onyx ("claw/hoof").

African clawless otter
On the banks of the Okavango River, Namibia
CITES Appendix II (CITES)[2]
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Aonyx
Lesson, 1827
Species:
A. capensis[1]
Binomial name
Aonyx capensis[1]
(Schinz, 1821)
African clawless otter range
Synonyms[3]
  • Anahyster calabaricus, Murray, 1860 Aonyx delalandi, Lesson, 1827
  • Lutra capensis, Schinz, 1821 Lutra inunguis, F. G. Cuvier, 1823
  • Lutra lenoiri, Rochebrune, 1888

Taxonomy edit

Aonyx capensis is a member of the weasel family (Mustelidae) and of the order Carnivora. The earliest known species of otter, Potamotherium valetoni, occurred in the upper Oligocene of Europe: A. capensis first appears in the fossil record during the Pleistocene.[4] Aonyx is closely related to the extinct giant Sardinian otter, Megalenhydris.[citation needed]

Subspecies edit

Mammal Species of the World lists six subspecies of the African clawless otter:[1]

  • A. c. capensis (Schinz, 1821)
  • A. c. hindei (Thomas, 1905)
  • A. c. meneleki (Thomas, 1903)
  • A. c. microdon (Pohle, 1920)
  • A. c. philippsi (Hinton, 1921)

Until recently the Congo clawless otter was considered a subspecies as well, but recent authorities treat it as a separate species A. congicus.[2][4]

Description edit

 
Skull of an African clawless otter

The African clawless otter has a chestnut-coloured thick, smooth fur with almost silky underbellies. It is characterized by white facial markings that extend downward towards its throat and chest areas. Paws are partially webbed with five fingers, but without opposable thumbs. All lack claws except for digits 2, 3, and 4 of the hind feet. Its large skull is broad and flat, with a relatively small orbit and a short snout. Molars are large and flat, used for crushing of prey. Male otters are slightly larger than females on average. Adults are 113–163 cm (44–64 in) in length, including their tails that comprised about a third of their length. Weights range from 10–36 kg (22–79 lb), with most otters averaging between 12 and 21 kg (26 and 46 lb). They are the third largest otter on average after the sea otter and giant otter and probably the third largest extant mustelid appearing to slightly outrival the wolverine, hog badger and European badger in mean body mass.[5][6] Despite being closely related to the Asian small-clawed otter, the African clawless otter is often twice as massive as that relatively diminutive mustelid.

Distribution and habitat edit

African clawless otters can be found anywhere from open coastal plains, to semiarid regions, to densely forested areas. Surviving mostly in southern Africa, the otters live in areas surrounding permanent bodies of water, usually surrounded by some form of foliage. Logs, branches, and loose foliage greatly appeal to the otter as this provides shelter, shade, and great rolling opportunities. Slow and rather clumsy on land, they build burrows in banks near water, allowing for easier food access and a quick escape from predators. In the False Bay area of the Cape Peninsula, they have been observed scavenging along beaches and rocks and hunting in shallow surf for mullet. They are mainly nocturnal in urban areas and lie up during the day in quiet, bushy areas.

Behaviour and ecology edit

 
African clawless otter in Toledo Zoo, Ohio
 
African Clawless Otter at a river mouth on the Southern African Coast

Though mostly solitary animals, African clawless otters will live in neighboring territories of family groups of up to five individuals. Each still having its own range within that territory, they mostly keep to themselves unless seeking a mate. Territories are marked using a pair of anal glands which secrete a particular scent. Each otter is very territorial over its particular range.

The African clawless otter spends its days swimming and catching food. They return to burrows (holts) for safety, cooling or a rubdown using grasses and leaves. Mainly aquatic creatures, their tails are used for locomotion and propel them through the water. They are also used for balance when walking or sitting upright.

Reproduction edit

Females give birth to litters containing two to five young around early spring. Mating takes place in short periods throughout the rainy season in December. Afterwards, both males and females go their separate ways and return to their solitary lives once more. Young are raised solely by the females. Gestation lasts around two months (63 days). Weaning takes place between 45 and 60 days, with the young reaching full maturity around one year of age.

Diet edit

The diet of Aonyx capensis primarily includes water-dwelling animals, such as crabs, fish, frogs and worms. They dive after prey to catch it, then swim to shore again, where they eat. Their fore paws come in handy as searching devices and are great tools for digging on the muddy bottoms of ponds and rivers, picking up rocks and looking under logs. Extremely sensitive whiskers (vibrissae) are used as sensors in the water to pick up the movements of potential prey.

Predation edit

Quick in the water and burrowing on land, the African clawless otter does not have many predators. Its greatest threat comes from the python, which will often lie in wait near or in the water. Other predators would include the crocodile and African fish eagle. If threatened, a high-pitched scream is emitted to warn neighboring otters and confuse a predator.

Thermoregulation edit

Living in Africa, environments can become very hot. Staying cool means spending time in the water, and using burrows as a way to escape the highest temperatures of the day. To stay warm, on the other hand, the otters depend solely on their thick fur. Guard hairs cover the body, acting as insulation. Since the otter lacks an insulating layer of body fat, its only means of warmth is provided by its thick coat of fur.

Threats edit

The biggest threat to African clawless otters comes from humans. Aonyx specimens will often forage in man-made fisheries and may be hunted or become entangled in nets. Overfishing by humans may reduce the food supply available to otters. They are sometimes hunted for their thick, soft pelts, which humans use in forms of clothing. In forested areas, logging may be a major threat, since erosion leads to greatly increased turbidity in rivers which can in turn greatly reduce the populations of fish on which the otters depend. This may well be a far greater threat to otters than hunting. The Otter Trail is a hiking trail in South Africa named after the African clawless otter, which is found in this area. Otters along the trail are protected, as it falls within the Tsitsikamma National Park.

References edit

  1. ^ a b Wozencraft, W. C. (2005). "Aonyx capensis". 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. 532–628. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ a b c d Jacques, H.; Reed-Smith, J. & Somers, M.J. (2021). "Aonyx capensis". IUCN Red List of Threatened Species. 2021: e.T1793A164575819. doi:10.2305/IUCN.UK.2021-3.RLTS.T1793A164575819.en. Retrieved 12 December 2022.
  3. ^ "Oldstyle id: 577b8ce82b7857d1ada9c14614d1240a". Catalogue of Life. Species 2000: Leiden, the Netherlands.
  4. ^ a b Larivière, S. (2001). "Aonyx capensis" (PDF). Mammalian Species (671): 1–6. doi:10.1644/1545-1410(2001)671<0001:ac>2.0.co;2. S2CID 198968982.
  5. ^ African Clawless Otter. 2011-08-30 at the Wayback Machine Arkive.org. 2011.
  6. ^ African Clawless Otter. The Animal Files. 2011.

Further reading edit

  • Somers, M. J. & Nel, J. A. J. (2000). "Habitat selection by the Cape clawless otter (Aonyx capensis) in rivers in the Western Cape Province, South Africa". African Journal of Ecology. 42 (4): 298–305. doi:10.1111/j.1365-2028.2004.00526.x.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • Somers, M. J. (2000). "Foraging behaviour of Cape clawless otters (Aonyx capensis) in a marine habitat". Journal of Zoology. 252 (4): 473–480. doi:10.1111/j.1469-7998.2000.tb01230.x.

External links edit

  • Animal Diversity Web
  • AmericaZoo

african, clawless, otter, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, a. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources African clawless otter news newspapers books scholar JSTOR August 2010 Learn how and when to remove this template message The African clawless otter Aonyx capensis also known as the Cape clawless otter or groot otter is the second largest freshwater otter species It inhabits permanent water bodies in savannah and lowland forest areas through most of sub Saharan Africa 2 It is characterised by partly webbed and clawless feet from which their name is derived The word aonyx means clawless derived from the prefix a without and onyx claw hoof African clawless otterOn the banks of the Okavango River NamibiaConservation statusNear Threatened IUCN 3 1 2 CITES Appendix II CITES 2 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaOrder CarnivoraFamily MustelidaeGenus AonyxLesson 1827Species A capensis 1 Binomial nameAonyx capensis 1 Schinz 1821 African clawless otter rangeSynonyms 3 Anahyster calabaricus Murray 1860 Aonyx delalandi Lesson 1827Lutra capensis Schinz 1821 Lutra inunguis F G Cuvier 1823Lutra lenoiri Rochebrune 1888 Contents 1 Taxonomy 1 1 Subspecies 2 Description 3 Distribution and habitat 4 Behaviour and ecology 4 1 Reproduction 4 2 Diet 4 3 Predation 4 4 Thermoregulation 5 Threats 6 References 7 Further reading 8 External linksTaxonomy editAonyx capensis is a member of the weasel family Mustelidae and of the order Carnivora The earliest known species of otter Potamotherium valetoni occurred in the upper Oligocene of Europe A capensis first appears in the fossil record during the Pleistocene 4 Aonyx is closely related to the extinct giant Sardinian otter Megalenhydris citation needed Subspecies edit Mammal Species of the World lists six subspecies of the African clawless otter 1 A c capensis Schinz 1821 A c hindei Thomas 1905 A c meneleki Thomas 1903 A c microdon Pohle 1920 A c philippsi Hinton 1921 Until recently the Congo clawless otter was considered a subspecies as well but recent authorities treat it as a separate species A congicus 2 4 Description edit nbsp Skull of an African clawless otterThe African clawless otter has a chestnut coloured thick smooth fur with almost silky underbellies It is characterized by white facial markings that extend downward towards its throat and chest areas Paws are partially webbed with five fingers but without opposable thumbs All lack claws except for digits 2 3 and 4 of the hind feet Its large skull is broad and flat with a relatively small orbit and a short snout Molars are large and flat used for crushing of prey Male otters are slightly larger than females on average Adults are 113 163 cm 44 64 in in length including their tails that comprised about a third of their length Weights range from 10 36 kg 22 79 lb with most otters averaging between 12 and 21 kg 26 and 46 lb They are the third largest otter on average after the sea otter and giant otter and probably the third largest extant mustelid appearing to slightly outrival the wolverine hog badger and European badger in mean body mass 5 6 Despite being closely related to the Asian small clawed otter the African clawless otter is often twice as massive as that relatively diminutive mustelid Distribution and habitat editAfrican clawless otters can be found anywhere from open coastal plains to semiarid regions to densely forested areas Surviving mostly in southern Africa the otters live in areas surrounding permanent bodies of water usually surrounded by some form of foliage Logs branches and loose foliage greatly appeal to the otter as this provides shelter shade and great rolling opportunities Slow and rather clumsy on land they build burrows in banks near water allowing for easier food access and a quick escape from predators In the False Bay area of the Cape Peninsula they have been observed scavenging along beaches and rocks and hunting in shallow surf for mullet They are mainly nocturnal in urban areas and lie up during the day in quiet bushy areas Behaviour and ecology edit nbsp African clawless otter in Toledo Zoo Ohio nbsp African Clawless Otter at a river mouth on the Southern African CoastThis section does not cite any sources Please help improve this section by adding citations to reliable sources Unsourced material may be challenged and removed November 2021 Learn how and when to remove this template message Though mostly solitary animals African clawless otters will live in neighboring territories of family groups of up to five individuals Each still having its own range within that territory they mostly keep to themselves unless seeking a mate Territories are marked using a pair of anal glands which secrete a particular scent Each otter is very territorial over its particular range The African clawless otter spends its days swimming and catching food They return to burrows holts for safety cooling or a rubdown using grasses and leaves Mainly aquatic creatures their tails are used for locomotion and propel them through the water They are also used for balance when walking or sitting upright Reproduction edit Females give birth to litters containing two to five young around early spring Mating takes place in short periods throughout the rainy season in December Afterwards both males and females go their separate ways and return to their solitary lives once more Young are raised solely by the females Gestation lasts around two months 63 days Weaning takes place between 45 and 60 days with the young reaching full maturity around one year of age Diet edit The diet of Aonyx capensis primarily includes water dwelling animals such as crabs fish frogs and worms They dive after prey to catch it then swim to shore again where they eat Their fore paws come in handy as searching devices and are great tools for digging on the muddy bottoms of ponds and rivers picking up rocks and looking under logs Extremely sensitive whiskers vibrissae are used as sensors in the water to pick up the movements of potential prey Predation edit Quick in the water and burrowing on land the African clawless otter does not have many predators Its greatest threat comes from the python which will often lie in wait near or in the water Other predators would include the crocodile and African fish eagle If threatened a high pitched scream is emitted to warn neighboring otters and confuse a predator Thermoregulation edit Living in Africa environments can become very hot Staying cool means spending time in the water and using burrows as a way to escape the highest temperatures of the day To stay warm on the other hand the otters depend solely on their thick fur Guard hairs cover the body acting as insulation Since the otter lacks an insulating layer of body fat its only means of warmth is provided by its thick coat of fur Threats editThe biggest threat to African clawless otters comes from humans Aonyx specimens will often forage in man made fisheries and may be hunted or become entangled in nets Overfishing by humans may reduce the food supply available to otters They are sometimes hunted for their thick soft pelts which humans use in forms of clothing In forested areas logging may be a major threat since erosion leads to greatly increased turbidity in rivers which can in turn greatly reduce the populations of fish on which the otters depend This may well be a far greater threat to otters than hunting The Otter Trail is a hiking trail in South Africa named after the African clawless otter which is found in this area Otters along the trail are protected as it falls within the Tsitsikamma National Park References edit a b Wozencraft W C 2005 Aonyx capensis 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 532 628 ISBN 978 0 8018 8221 0 OCLC 62265494 a b c d Jacques H Reed Smith J amp Somers M J 2021 Aonyx capensis IUCN Red List of Threatened Species 2021 e T1793A164575819 doi 10 2305 IUCN UK 2021 3 RLTS T1793A164575819 en Retrieved 12 December 2022 Oldstyle id 577b8ce82b7857d1ada9c14614d1240a Catalogue of Life Species 2000 Leiden the Netherlands a b Lariviere S 2001 Aonyx capensis PDF Mammalian Species 671 1 6 doi 10 1644 1545 1410 2001 671 lt 0001 ac gt 2 0 co 2 S2CID 198968982 African Clawless Otter Archived 2011 08 30 at the Wayback Machine Arkive org 2011 African Clawless Otter The Animal Files 2011 Further reading editSomers M J amp Nel J A J 2000 Habitat selection by the Cape clawless otter Aonyx capensis in rivers in the Western Cape Province South Africa African Journal of Ecology 42 4 298 305 doi 10 1111 j 1365 2028 2004 00526 x a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Somers M J 2000 Foraging behaviour of Cape clawless otters Aonyx capensis in a marine habitat Journal of Zoology 252 4 473 480 doi 10 1111 j 1469 7998 2000 tb01230 x External links editAnimal Diversity Web AmericaZoo Otternet Itech African Clawless Otter Retrieved from https en wikipedia org w index php title African clawless otter amp oldid 1189616980, wikipedia, wiki, book, books, library,

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