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Lutra lutra

(Eurasian river otter)

Overview

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Near Threatened

Threat status

Interesting Facts

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Common Names

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Click on the language to view common names.

Common Names in Chinese:

shui-ta

Common Names in Dutch:

Euraziatische otter of visotter, Otter

Common Names in English:

Eurasian river otter, Common otter, Eurasian otter, European otter, European Otter;european River Otter;otter, European river otter, Old world otter

Common Names in French:

Loutre commune, Loutre d'europe, Loutre De Rivi?re, loutre de rivière

Common Names in Russian:

Выдра обыкновенная

Common Names in Spanish:

NUTRIA, Nutria Com?n, Nutria común

Description

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Habitat

Typically found at an altitude of 0 to 4,400 meters (0 to 14,436 feet).[1]

Ecology: The Eurasian otter live in a wide variety of aquatic habitats , including highland and lowland lakes , rivers , streams , marshes, swamp forests and coastal areas independent of their size, origin or latitude (Mason and Macdonald 1986). In Europe they are found in the brackish waters from the sea level up to 1,000 m in the Alps (Ruiz-Olmo and Gosalbez 1997) and above 3,500 m in the Himalayas (Prater 1971) or 4,120 m in Tibet (Mason and Macdonald 1986). In the Indian sub-continent, the Eurasian otters occur in cold hill and mountain streams. During summer (April - June) in the Himalayas they may ascend up to 3,660 m. These upward movements probably coincide with the upward migration of the carp and other fish for spawning. With the advent of winter the otters come down to lower altitudes (Prater 1971). In a study conducted in Thailand in Huai Kha Khaeng where the Eurasian, smooth-coated and small-clawed otters live sympatrically, Kruuk et al. (1994) found that the Eurasian otters used rapidly flowing upper parts of the river. In Sri Lanka the Eurasian otter was live in the headwaters of all the five river systems but not in the estuaries (de Silva 1996).

In most parts of its range , its occurrence is correlated with bank side vegetation showing importance of vegetation to otters (Mason and Macdonald 1986). Otters in different regions may depend upon differing features of the habitat , but to breed , they need holes in the river bank, cavities among tree roots , piles of rock, wood or debris . The Eurasian otters are closely connected to a linear living space. Most portion of their activity is concentrated to a narrow strip on either side of the interface between water and land (Kruuk 1995). Otter distribution in coastal areas especially the location of holts, is strongly correlated with the presence of freshwater (Kruuk et al. 1989, Beja 1992).

Within the group home range , shared by resident adult females, each had her own core area . Resident males had larger home ranges in more exposed parts of the coast which overlapped with other males and with at least two female group ranges. Male and female transients moved through group ranges, relegated to less favoured holts, habitat and food. In freshwater home ranges are longer for both sexes (Kruuk 1995). Erlinge (1969) suggested that males were hierarchical and territorial , influenced by sexual factors , while female ranges were influenced by food and shelter requirements of the family group. Green et al. (1984) and Kruuk (1995) found that adult males spent most of their time along the main rivers , whereas adult females occupied tributaries or lakes, as they did in Austria (Kranz 1995). Rosoux (1995) found no sexual differences in habitat utilization and considerable overlaps in range. Young animals usually occupied peripheral habitat, but Green and Green (1983) found differences between immature and mature young males, the later having access to all available habitat and the other restricted to marginal habitat , supplemented by visits to the main river when vacant, temporally or spatially. While males generally have larger ranges than females in the same habitat, sizes vary according to the type and productivity of the habitat, and methods of measuring ranges vary from study to study.

Like most Lutra species, fish is the major prey of Eurasian otters sometimes exceeding more than 80% of their diet (Erlinge 1969, Webb 1975, Ruiz-Olmo and Palazon 1997). In addition to fish a whole range of other prey items have been recorded in their diet in variable proportions. These include aquatic insects, reptiles , amphibians , birds, small mammals, and crustaceans (Jenkins et al. 1980, Adrian and Delibes 1987, Skaren 1993). In a study conducted in Sri Lanka, Silva (1996) reported that the overall diet of the Eurasian otters consisted of 81.2% of crab, 37.5% fish and 8.7% frog . In addition to these the diet also included small quantities of water snakes , birds, small mammals and insects.

The percentage of crab in the diet of the Eurasian otters in Sri Lanka varied from 72% to 85%, and fish from 25-31%. There was significant seasonal variation in the diet in different habitats. The relative importance of fish in the diet was significantly higher in the reservoirs and lakes than the rivers and streams. Crabs were more important to otters inhabiting streams than those inhabiting rivers and lakes. Crabs were eaten more than fish during the monsoon (de Silva, 1997). However, in Huai Kha Kheng, Thailand 76% of the spraint had fish, 64% amphibians and 7% crab (Kruuk et al. 1994). The Eurasian otter is capable of taking fish as large as 9 kg (Chanin 1985), however, many studies in Europe have revealed that the fish consumed by the Eurasian otters are relatively small with a median length of 13 cm (Kruuk 1995).

The Eurasian otter is largely solitary and the adult otters tend not to associate with other adults except for reproduction . The family group of mother and offspring is the most important unit of otter society. In Shetland, where several adult animals used the same stretch of coast, encounters between adults were rare (Kruuk 1995) and the species was strikingly non-social. Kranz (1995) found evidence of social group formation beyond the occasional associations of two or more family groups, which suggests that under some circumstances otters of all ages and sexes may form temporary mutually tolerant gatherings.

In most of its range the Eurasian otter is predominantly nocturnal (Green et al. 1984). The exception is Shetland, where otters were entirely diurnal (Kruuk 1995). Green et al. (1984) found that activity was largely circumscribed by the solar rhythm so that the duration of activity varied through the year with night length . The reverse situation was found in Shetland with activity restricted by the day length (Kruuk 1995). Some workers have found a break in activity in the middle of longer nights or days and single peak around midnight or midday in shorter nights or days, although up to four activity periods per night has been recorded. Kruuk (1995) links otter activity to that of prey species, with the favoured marine species more vulnerable in daylight and those in freshwater easier to catch at night. In coastal habitats, tidal patterns influence otter activity, with significant preference shown for feeding at low tide , both in Shetland and on the Scottish west coast (Kruuk 1995).

The Eurasian otter attains sexual maturity at around 18 months in males and 24 months in the case of females, but in captivity it is usually 3 to 4 years (Reuther 1991). They are non-seasonally polyoestrous (Trowbridge 1983), mating in captivity has been observed at all times of the year (Reuther 1999). The gestation period is approximately 63-65 days, the litter size varies from 1 to 5, and the life expectancy is around 17 years (Acharjyo and Mishra 1983).[2].

List of Habitats:

Taxonomy

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Synonyms

Encentrum lutra Wulfert • Lutra nippon

Notes

Name Status: Accepted Name .

Last scrutiny: 15-Aug-2007

Seven subspecies were reported by Pocock (1941) (1) L. l. lutra in Europe and northern Africa; (2) L. l. nair in southern India and Sri Lanka; (3) L. l. monticola in northern India (Himachal Pradesh, Sikkim and Assam) Nepal, Bhutan and Myanmar; (4) L. l. kutab in northern India - Kashmir; (5) L. l. aurobrunnea in Garhwal Himalayas in northern India and higher altitudes in Nepal; (6) L. l. barang in southeast Asia (Thailand, Indonesia and Malaysia); and (7) L. l. chiensis in southern China and Taiwan. Imaizumi and Yoshiyuki (1989) considered Japanese otters a distinct species (L. nippon). It is treated separately by Wozencraft in Wilson and Reeder (2005), but that approach is not followed here pending further review.[2].

Similar Species

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Members of the genus Lutra

ZipcodeZoo has pages for 7 species and subspecies in this genus:

L. canadensis (Canadian Otter;river Otter) · L. canadensis canadensis (River Otter) · L. lutra (Eurasian River Otter) · L. lutra lutra (European Otter) · L. maculicollis (Speckle-Throated Otter) · L. nippon (Blacksaddle Goatfish) · L. sumatrana (Hairy-Nosed Otter)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal November 18, 2007:

Identifiers

Footnotes

  1. Mean = 328.820 meters (1,078.806 feet), Standard Deviation = 779.030 based on 6,945 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
  2. Ruiz-Olmo, J., Loy, A., Cianfrani, C., Yoxon, P., Yoxon, G., de Silva, P.K., Roos, A., Bisther, M., Hajkova, P. & Zemanova, B. 2008. Lutra lutra. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 01 February 2012. [back]
Last Revised: 7/15/2012