http___en.wikipedia.org_wiki_African_clawless_otter_3.xml
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Капска видра Капската видра[2] (Aonyx capensis) е вид хищен африкански бозайник от семейство Порови. Това е втората по големина на тялото сладководна видра. Характеризира се с частично лопатковидна форма на безноктестата ръка откъдето идва и другото име, с което е наричан вида - Африканска безнокта видра. Съдържание Разпространение и местообитание[редактиране | edit source] Капската видра обитава постоянни водоеми, разположени в близост до саваната, както равнинни и горски местности в Субсахарска Африка, с изключение на басейна на река Конго и сухите райони.[1] Класификация[редактиране | edit source] Капската видра еволюира през плейстоцен[3]. Изследнавията сочат, че видът е родствен с изчезналата Сардинска видра - Megalenhydris. Mammal Species of the World описва шест подвида на капската видра Aonyx capensis:[2] - Aonyx capensis capensis (Schinz, 1821) - Aonyx capensis hindei (Thomas, 1905) - Aonyx capensis meneleki (Thomas, 1903) - Aonyx capensis congica, Камерунска безнокта видра (Lönnberg, 1910) - Aonyx capensis microdon (Pohle, 1920) - Aonyx capensis philippsi (Hinton, 1921) Други автори[1][3] отделят Камерунската безнокта видра в отделен вид (Aonyx congicus). Според същите източници подвидовете на капската видра са три - първите от списъка. Морфологични особености[редактиране | edit source] Африканската безнокта видра има дебела кожа и гладка козина, която в областта на корема е копринена при допир. Цветът на козината е кафяв като муцуната, врата и гръдния кош е бяла. При младите екземпляри и коремът е бял. Косъмът е с дължина 5 - 6 mm като в областта на гърба достига до 1 cm.[4]. Дължината на тялото варира от 70 до 100 cm, а опашката е с размери 40 - 70 сантиметра. Средното тегло на животното е 12 - 21 kg. Ушите са малки и кръгли, около 3cm. Лапите имат лопатковидна форма, с пет пръста като палецът не се противопоставя на останалите. Нокти липсват на предните крайници, а при задните е възможно да има на средните пръсти. Те обаче са малки и наподобяват на човешки. Предните лапи са много чувствителни и пръстите са много мобилни. Черепът е голям и просък със сравнително малки орбити и широка муцуна. Зъбите са големи и плоски като се използват за раздробяване на плячката. Начин на живот и хранене[редактиране | edit source] Капските видри се хранят основно с водни видове животни - раци, риби, жаби и червеи. Те се гмуркат във водата като преследват плячката. След като я уловят я изнасят на брега за да я изядат. Ръцете им са приспособени за копаене в тинестото дъно и откриване на плячката. Мустаците им са изключително чувствителни и случат като сензори улавящи движението на плячката. Размножаване[редактиране | edit source] Чифтосването се извършва през дъждовния сезон през декември. След това двойките се развалят и всеки заживява поединично. Женските раждат рано напролет по 2 - 5 малки. Младите се отглеждат изцяло от женските. Бременността продължава около 2 месеца (63 дни). Отбиването на малките става на 45 – 60 ден, а половата зрялост настъпва на около 1 година след раждането. Източници[редактиране | edit source] - ↑ а б в ((en)) Hoffmann, M.. Aonyx capensis. // IUCN Red List of Threatened Species. International Union for Conservation of Nature, 2008. Посетен на 2 Aug 2010. - ↑ а б Wozencraft, W. Mammal Species of the World. 3rd edition. Johns Hopkins University Press, 16 November 2005. - ↑ а б Larivière, Serge. Aonyx Capensis. // Mammalian Species 671. 5 June 2001. с. 1–6. - ↑ Animal diversity 2006
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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 species of otter. African clawless otters are found near permanent bodies of water in savannah and lowland forest areas. They range through most of sub-Saharan Africa, except for the Congo basin and arid areas.[2] They are characterized by partly webbed and clawless feet, from which their name is derived. [edit] Taxonomy 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.[3] Aonyx is closely related to the extinct giant Sardinian otter, Megalenhydris. [edit] Subspecies Mammal Species of the World lists six subspecies of Aonyx capensis:[1] - Aonyx capensis capensis (Schinz, 1821) - Aonyx capensis hindei (Thomas, 1905) - Aonyx capensis meneleki (Thomas, 1903) - Aonyx capensis congica (sic) (Lönnberg, 1910) - Aonyx capensis microdon (Pohle, 1920) - Aonyx capensis philippsi (Hinton, 1921) However some authorities[2][3] consider the Congo/Cameroon clawless otter to be a separate species (A. congicus). Under this view, only the first three of the above list would be subspecies of A.capensis. [edit] Description African clawless otters have thick, smooth fur with an almost silky underbelly. Chestnut in color, they are characterized by white facial markings that extend downward towards their throat and chest areas. Paws are partially webbed with five fingers, and no opposable thumbs. All lack claws except for digits 2, 3, and 4 of the hind feet. Their large skulls are broad and flat, with relatively small orbits and short rostra. Molars are large and flat, used for crushing of prey. Male otters are slightly larger than females on average. Adults are 113–163 cm (45–64 in) in length, including their tails that comprised about a third of their length. Weights can range from 10–36 kg (22-80 lbs), with most otters averaging between 12 and 21 kg (26-46 lbs).[4][5] Despite being closely related to the oriental small-clawed otter, the African clawless otter is often twice as massive as that relatively diminutive mustelid. [edit] Habitat 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. [edit] Reproduction 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. [edit] Diet 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. [edit] Behavior 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. Awkward on land but acrobats in the water, these animals spend their days swimming and catching food. They return to underground 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. [edit] Predation Quick in the water and burrowing on land, A. capensis does not have many predators. Its greatest threat comes from the python, which will often lay in wait near or in the water. Other predators would include the crocodile and fish eagles. If threatened, a high-pitched scream is emitted to warn neighboring otters and confuse a predator. [edit] Thermoregulation Living in Africa, environments can become very hot. Staying cool means spending time in the water, and also 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. [edit] Economic impact 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 the trail falls within the Tsitsikamma National Park. [edit] References - ^ a b Wozencraft, W. C. (2005). "Aonyx capensis". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. http://www.bucknell.edu/msw3/browse.asp?id=14001078. - ^ a b c Hoffmann, M. (2008). "Aonyx capensis". IUCN Red List of Threatened Species. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/1793. Retrieved 2 Aug 2010. - ^ a b Larivière, Serge (5 June 2001). "Aonyx capensis". Mammalian Species 671: 1–6. http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/671_Aonyx_capensis.pdf. - Michael J. Somers and Jan A. J. Nel. Habitat selection by the Cape clawless otter (Aonyx capensis) in rivers in the Western Cape Province, South Africa, African Journal of Ecology 42: pg 298-305. - Michael J Somers. 2000 Foraging Behavior of Cape Clawless Otters (Aonyx capensis) in a marine habitat., Journal of Zoology, 252: pg 473-480.