Eurasian otter

The Eurasian otter (Lutra lutra), also known as the European otter, Eurasian river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia. The most widely distributed member of the otter subfamily (Lutrinae) of the weasel family (Mustelidae), it is found in the waterways and coasts of Europe, many parts of Asia, and parts of northern Africa. The Eurasian otter has a diet mainly of fish, and is strongly territorial. It is endangered in parts of its range, but recovering in others.

Description

The Eurasian otter is a typical species of the otter subfamily. Brown above and cream below, these long, slender creatures are well-equipped for their aquatic habits. Their bones show osteosclerosis, increasing their density to reduce buoyancy.[2] This otter differs from the North American river otter by its shorter neck, broader visage, the greater space between the ears and its longer tail.[3] However, the Eurasian otter is the only otter in much of its range, so it is rarely confused for any other animal. Normally, this species is 57 to 95 cm (22.5 to 37.5 in) long, not counting a tail of 35–45 cm (14–17.5 in). The female is shorter than the male.[4] The otter's average body weight is 7 to 12 kg (15 to 26 lb), although occasionally a large old male may reach up to 17 kg (37 lb).[5][6] The record-sized specimen, reported by a reliable source but not verified, weighed over 24 kg (53 lb).[7]

Range and habitat

The Eurasian otter is the most widely distributed otter species, its range including parts of Asia and Africa, as well as being spread across Europe, south to Israel. Though currently believed to be extinct in Liechtenstein and Switzerland, they are now very common in Latvia, along the coast of Norway, in the western regions of Spain and Portugal and across Great Britain, especially Shetland, where 12% of the UK breeding population exists.[8]Ireland's otters are geographically widespread and believed to be the most stable population in Europe.[9] In Italy, they can be found in southern parts of the peninsula. The South Korean population is endangered. In India, the species is distributed in the Himalayan foothills, southern Western Ghats and the central Indian landscape.[10]

In general, their varied and adaptable diets mean they may inhabit any unpolluted body of fresh water, including lakes, streams, rivers, and ponds, as long as the food supply is adequate. In Andalusia the golf courses became part of their habitat.[11] Eurasian otters may also live along the coast, in salt water, but require regular access to fresh water to clean their fur. When living in the sea, individuals of this species are sometimes referred to as "sea otters", but they should not be confused with the true sea otter, a North Pacific species much more strongly adapted to a marine existence.

Diet

Otter feeding on fish

Video of otters eating frozen fish in the Aquarium of Gijón, Spain

The Eurasian otter's diet mainly consists of fish.[12] Fish is their most preferred choice of food in Mediterranean and temperate freshwater habitats.[13] During the winter and in colder environments, though, fish consumption is significantly lower, and the otters use other sources of food, including amphibians,[14][15]crustaceans, insects, birds and sometimes small mammals, including young beavers.[16]

Behaviour and reproduction

Skull

Eurasian otters are strongly territorial, living alone for the most part. An individual's territory may vary between about 1 and 40 km (1–25 mi) long, with about 18 km (11 mi) being usual. The length of the territory depends on the density of food available and the width of the water suitable for hunting (it is shorter on coasts, where the available width is much wider, and longer on narrower rivers).The Eurasian otter uses its feces, spraints, to mark its territory and prioritize the use of resources to other group members.[17] The territories are only held against members of the same sex, so those of males and females may overlap.[18]Mating takes place in water. Eurasian otters are nonseasonal breeders (males and females will breed at any time of the year) and it has been found that their mating season is most likely determined simply by the otters' reproductive maturity and physiological state. Female otters become sexually mature between 18 and 24 months old and the average age of first breeding is found to be ​21⁄2 years. Gestation for the Eurasian otter is 60–64 days, the litter weighing about 10% of the female body mass. After the gestation period, one to four pups are born, which remain dependent on the mother for about 13 months.[19] The male plays no direct role in parental care, although the territory of a female with her pups is usually entirely within that of the male.[18] Hunting mainly takes place at night, while the day is usually spent in the Eurasian otter's holt (den) – usually a burrow or hollow tree on the riverbank which can sometimes only be entered from underwater. Though long thought to hunt using sight and touch only, evidence is emerging that they may also be able to smell underwater – possibly in a similar manner to the star-nosed mole.[20][21]

Conservation

A Eurasian otter skeleton

The Eurasian otter declined across its range in the second half of the 20th century[22] primarily due to pollution from pesticides such as organochlorine and polychlorinated biphenyls. Other threats included habitat loss and hunting, both legal and illegal.[23] Eurasian otter populations are now recovering in many parts of Europe. In the United Kingdom, the number of sites with an otter presence increased by 55% between 1994 and 2002. In August, 2011, the Environment Agency announced that otters had returned to every county in England since vanishing from every county except the West Country and parts of Northern England.[24] Recovery is partly due to a ban on the most harmful pesticides that has been in place across Europe since 1979,[25] partly to improvements in water quality leading to increases in prey populations, and partly to direct legal protection under the European Union Habitats Directive[26] and national legislation in several European countries.[27][28][29] In Hong Kong, it is a protected species under Wild Animals Protection Ordinance Cap 170. It is listed as Near Threatened by the IUCN Red List.[1]

Most species that are victims of population decline or a loss of habitat tend to eventually lose their genetic difference due to inbreeding from small populations. A study conducted in 2001, examined whether or not the populations of Eurasian otters suffered from a lack of genetic variability. In the study, they examined teeth of otter skulls at the Zoological Museum, Copenhagen and the Natural History Museum, Aarhus. The samples were collected between 1883 and 1963 in Denmark (Funen, Zealand, and Jutland). The study examined the tissue on the teeth of the skulls and determined the genetic variability based on DNA analysis. In conclusion, the study discovered that despite the population declines, the Eurasian otter was not a victim of declining genetic variability.[30]

^Alleyne, Richard (2010-06-05). "Can otters smell underwater?". Daily Telegraph. London. Archived from the original on 2010-06-06. Retrieved 2010-06-06. Hamilton James said: “I always had an inkling that otters could smell under water and I wanted to prove it. As it was dark and the fish was fully submerged, it proved that the otters had to be using a sense other than sight or touch to locate it. After reviewing the footage I noticed a tiny bubble which hit the fish and was sniffed back in by the otter.”

External links

Drawa National Park (Polish: Drawieński Park Narodowy) is located in north-western Poland, on the border of Greater Poland, Lubusz and West Pomeranian Voivodeships. The park is a part of the huge Drawsko Forest (Puszcza Drawska), which lies on the vast Drawsko Plain. It takes its name from the River Drawa. It was created in 1990 and initially covered 86.91 km². Later, it was enlarged to 113.42 square kilometres (43.79 sq mi) of which forests account for 96.14 km² (3.68 km² is designated as a strictly protected area), and water bodies cover 9.37 km².

The Fir of Hotovë-Dangelli National Park (Albanian: Parku Kombëtar "Bredhi i Hotovës-Dangëlli") is the largest national park in Albania located in Gjirokastër County with a surface area of 34,361 ha (343.61 km2). The park takes its name from the Hotova Fir, which is considered one of the most important Mediterranean plant relics of the country. Although, it encompasses of hilly and mountainous terrain composed of limestone and sandstone deposits, with numerous valleys, canyons, gorges, rivers and dense deciduous and coniferous forests. The International Union for Conservation of Nature (IUCN) has listed the park as Category II. The park also includes 11 natural monuments.

The park rises over a very remote mountainous region of Nemërçka and Tomorr between the Vjosa Valley in the west, Leskovik in the south, Erseka in the southeast and the Osum Valley in the northeast. Close to Petran is the narrow and deep Lengarica Canyon with numerous caves and thermal springs such as Banjat e Bënjës. Within the boundaries of the park there are numerous villages including Frashër, which is well known located in the heart of the park. In terms of hydrology, Vjosa is the main river forming the western bound of the park, flowing through Përmet until discharging into the Adriatic Sea.The park experiences mediterranean climate with moderate rainy winters and dry, warm to hot summers. During winter, visitors can appreciate the snow blanket covering the firs, and in the summer the abundance of fresh air away as an escape from the Albanian summer heat. Its mean monthly temperature ranges between 3 °C (37 °F) in January and 30 °C (86 °F) in August with annual precipitation ranging between 500 millimetres (20 inches) and 1,800 millimetres (71 inches) depending on geographic region and prevailing climate type.Due to its favorable ecological conditions and the mosaic distribution of various types of habitats, it is characterized by exceptionally rich and varied fauna. The forests are the most important habitats for mammals like wild cat, roe deer, wild boar, red squirrel, eurasian otter and badger. Brown bear, gray wolf and red fox can also be seen on the pastures deep inside the forest. The old growing trees throughout the park preserves a wide variety of bird species. Most notable amongst them are the golden eagle, eagle owl, barn owl, sparrowhawk, egyptian vulture, kestrel, lanner falcon and so on.

Some of the park’s main attractions include:

Frasheri Brothers Tower House and Museum in Frasher reconstructed in the 1970s by the Albanian government. The museum features documents, photographs, and sculptures on Frasheri Brothers origins and their contribution to the Albanian Renaissance.

Langarica Canyon perfect for rafting

Katiu Ottoman Bridge and Benja Thermal Waters

Variety of trails around the area are marked and can be found HEREAs elsewhere in Albania, this national park is being threatened by the construction of hydroelectric dams along the Langarica Canyon. Environmentalists are challenging such activity by holding protests in Tirana as works are underway in the affected area which could damage ecosystems and the livelihood of those catering to the tourism industry.

The Gashi River (Albanian: Lumi i Gashit) is a 27 km (17 mi) long river located in Tropojë, northern Albania.

It is a nature reserve, spanning an area of 3,000 ha (7,400 acres). The nature reserve forms a part of the European Green Belt and has been declared a UNESCO World Heritage Site within the Primeval Beech Forests of the Carpathians and Other Regions of Europe.The river is located in the eastern part of the Albanian Alps at 2,175 m (7,136 ft) above sea level. It originates at the Dobërdol Pass 2,238 m (7,343 ft) and flows through numerous peaks including the Trekufiri 2,354 m (7,723 ft) in the north, Maja Bogiçaj 2,405 m (7,890 ft) in the northeast, and Maja e Shpatit 21,995 m (72,162 ft) in the northwest. The various streams, flowing first to the north and northwest, merge with the Dobërdol pasture in the northwest, than leaving the basin westward. Few kilometres further the river changes its course southwards and stops the direction in the sequence. It passes the Maja e Shkëlzenit 2,405 m (7,890 ft) on its western side. Further south, the river passes through a narrow gorge and valley to the Tropoja basin, where the river below flows into the Valbonë river.

The climate is subarctic and oceanic, having cool summers and generally cold winters. Forests occupy the majority of the region's area. The region falls within the Balkan mixed forests and Dinaric mixed forests terrestrial ecoregion of the Palearctic Temperate broadleaf and mixed forest. The river is particularly known for the diversity of flora and fauna and is surrounded by swamps and canals that drain the whole local basin such as the region of Malësia e Gashit within the Albanian Alps into the Adriatic sea. Forests occupy the majority of the total area.

The flora of the region is diverse and is characterized with high endemism due to the combination of southern geographic latitude and high altitude variation. The forests are host to several plants such as beech, macedonian pine, bosnian pine, norway spruce, and silver fir. The fauna is represented by 64 species of mammals, such as the brown bear, gray wolf, chamois, lynx, roe deer, wild boar, western capercaillie, golden eagle, eurasian otter and 14 species of amphibians.

Ghodaghodi Tal is a Ramsar site in western Nepal. Established in August 2003 it covers an area of 2,563 ha (6,330 acres) in Kailali District at an altitude of 205 m (673 ft) on the

lower slopes of the Siwalik Hills. This Ramsar site consists of a system of around 13 large and shallow oxbow lakes and ponds with associated marshes and meadows. It is surrounded by tropical deciduous forest and some streams along the periphery, which are separated by hillocks.

Kobuleti Strict Nature Reserve (Georgian: ქობულეთი) is a protected area in Kobuleti Municipality, Adjara region of Georgia along the Black Sea coast in the northern part of the resort town Kobuleti.Kobuleti Protected Areas were established in 1998 to preserve unique wetland ecosystems recognized by the Ramsar Convention.

Kobuleti Protected Areas include Kobuleti Strict Nature Reserve and Kobuleti Managed Reserve located on left and right banks of Shavi Ghele (black creek) river respectively.Kobuleti Strict Nature Reserve occupies territory bordered by the Togoni river on the north, the Kobuleti—Ozurgeti highway on the east, Shavi Ghele river on the south and Kobuleti suburbs on the west.

Lake Koman (Albanian: Liqeni i Komanit) is a reservoir on the Drin River in northern Albania. Lake Koman is surrounded by dense forested hills, vertical slopes, deep gorges, and a narrow valley, completely taken up by the river. Besides the Drin, it is fed by the Shala and Valbona Rivers. The lake stretches in an area of 34 km2 (13 sq mi), its width being 400 m (0.25 mi). The narrowest gorge, which is surrounded by vertical canyon walls, is more than 50 m (0.031 mi) wide. The reservoir was constructed between 1979 and 1988 near the village of Koman with a height of 115 m (377 ft).The combination of specific topography and hydrological conditions, have contributed to the formation of different habitats. The golden jackal, red fox, european badger, eurasian otter, beech marten, european polecat are the primary predatory mammals. A high number of bird species have been observed in the region, including the common kingfisher, common quail, grey heron, eurasian wryneck, great spotted woodpecker and black-headed gull.The Lake Koman Ferry operates daily on the lake from Koman to Fierza. The ferry connects the city of Bajram Curri to the region of Tropojë. The journey takes about two and a half hours and is also popular with the foreign tourists. Smaller boats bring people and goods to remote villages, which are often far away from the lake, but can only be reached by water.

The Mesopotamian Marshes or Iraqi Marshes are a wetland area located in southern Iraq and partially in southwestern Iran and Kuwait. Historically the marshlands, mainly composed of the separate but adjacent Central, Hawizeh and Hammar Marshes, used to be the largest wetland ecosystem of Western Eurasia. It is a rare aquatic landscape in the desert, providing habitat for the Marsh Arabs and important populations of wildlife. Draining of portions of the marshes began in the 1950s and continued through the 1970s to reclaim land for agriculture and oil exploration. However, in the late 1980s and 1990s, during the presidency of Saddam Hussein, this work was expanded and accelerated to evict Shia Muslims from the marshes. Before 2003, the marshes were drained to 10% of their original size. After the fall of Hussein's regime in 2003, the marshes have partially recovered but drought along with upstream dam construction and operation in Turkey, Syria and Iran have hindered the process. Since 2016 the mesopotamian marshes are listed as an UNESCO Heritage Site.

The Mustelidae (; from Latin mustela, weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, mink, and wolverines, among others. Mustelids are diverse and the largest family in the order Carnivora, suborder Caniformia. Mustelidae comprises about 56-60 species across eight subfamilies.

Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the weasel family Mustelidae, which also includes badgers, honey badgers, martens, minks, polecats, and wolverines.

Reed beds are natural habitats found in floodplains, waterlogged depressions, and

estuaries. Reed beds are part of a succession from young reeds colonising open water or wet ground through a gradation of increasingly dry ground. As reed beds age, they build up a considerable litter layer that eventually rises above the water level and that ultimately provides opportunities for scrub or woodland invasion. Artificial reed beds are used to remove pollutants from grey water.

The smooth-coated otter (Lutrogale perspicillata) is an otter species occurring in most of the Indian subcontinent and Southeast Asia, with a disjunct population in Iraq. As its name indicates, the fur of this species is smoother and shorter than that of other otter species.

The Sri Lanka tree crab, (Perbrinckia scansor), is a species of freshwater crabs of the family Gecarcinucidae that is endemic to Sri Lanka. It is the only known tree climbing freshwater crab found in the country. The crab is discovered from 11 localities from Sri Lanka throughout Kalu River, Walawe River and Gin River basins. Adult are known to survive well in rainwater-filled tree hollows of trees such as Shorea sp., Artocarpus sp., Dillenia sp., Garcinia sp., Myristica sp., and Gyrinops walla. Females with youngs can be seen during February and March on the ground, never within tree hollows. The known predators are Greater coucal, White-throated kingfisher, Sri Lanka grey hornbill and Eurasian otter.The species is categorized as least concern by IUCN, but the habitats are gradually declining. The water bodies of central hills are invaded by exotic species of fish and other aquatic flora and usage of many areas for human habitations are known to harm the animal. They are also collected illegally and used for many purposes local and overseas.

The Water of Aven (or A'an) (Scottish Gaelic: an t-Uisge Bàn) is a tributary of the Water of Feugh, itself the largest tributary of the River Dee, Aberdeenshire, Scotland. The Water of Aven rises at Loch Tennet, where the historic counties of Aberdeenshire, Angus and Kincardineshire meet and flows for approximately 15 km to its confluence with the Feugh near Whitestone. The Water of Aven forms the historic boundary between Aberdeenshire and Kincardineshire for its entire length and the lower 4.5 km are designated as part of the River Dee Special Area of Conservation, due to its importance for Atlantic salmon and Eurasian otter.

The wildlife of Sweden includes the diverse flora and fauna of Sweden. The native plants and animals are adapted to the geography and climate of this country in northwestern Europe. The country has a long coastline and the habitats include mountains, hills, tundras, forests, rivers, lakes and cultivated land. The climate is in general very mild for a country at this latitude, because of the significant maritime influence.

This page is based on a Wikipedia article written by authors
(here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.