Otters



Singapore Infopedia

Background

Otters are from the Lutrinae subfamily, a branch of the Mustelidae family whose other branches include weasels, badgers and minks.1 Otters have long sleek bodies suited for hunting fish, crustaceans and shellfish along the coast and in rivers and other water bodies.2 The two otter species found in Singapore – the small-clawed otter (Aonyx cinerea) and the smooth-coated otter (Lutrogale perspicillata) – have crossbred.3 Since the late 1990s, smooth-coated otters have been increasingly sighted along the northern coast of Singapore and in canals and rivers.4

Description
Medium-sized mammals, otters have adapted to hunting in water, resulting in long sleek bodies suitable for diving and swimming. They have webbed feet, small ears, short but broad muzzles, and tails that are shorter than their bodies.5 Living in family groups of up to a dozen individuals, otters hunt in and protect their territory.6

The commonly seen smooth-coated otters have head-body lengths of up to 75 cm and tail lengths of up to 45 cm.7 The lower half of their tails are a little flattened.8 Their fur is short, smooth and brown on the underside, and their throats and cheeks are pale yellowish-brown.9 Their clawed feet are webbed between the digits.10

Their more petite relative, the small-clawed otter, has head-body lengths of up to 50 cm and tails of up to 33 cm.11 Their fur is light brown on the underside, while their throat and sides of the neck are pale.12 Their feet are only partially webbed, with claws not extending beyond the digits.13

Diet and habitat
Otters are carnivorous. The larger smooth-coated otters subsist mainly on fish, and small-clawed otters feed more on crustaceans and molluscs. This may be why the former is mostly found along the coast and in larger rivers, while the latter forages within forested mangroves, ponds and streams.14 Both have regular spraint sites to mark their territory.15

Reproduction
Otters have a gestation period of about 60 days.16 Just before giving birth, the smooth-coated otter mother retreats into a suitable den or holt where it will give birth to up to five babies and suckle them.17 Small-clawed otters may have up to two litters of one to two pups a year.18

Otter sightings
In the colonial times, small-clawed otters were found inland and in the mangroves, while the larger Lutra otters (both the smooth-coated otter and the Lutra sumatrana or hairy-nosed otter) were spotted only occasionally along the coast and thought to be visitors.19 By the 1970s, it was thought that there were no resident otters in Singapore.20 From the 1990s, when Sungei Buloh was established, regular otter sightings were reported there, as well as along the northern coastline, and in Pulau Ubin and Pulau Tekong.21 Eventually the otter families spread south, and by 2017, Singapore had an estimated population of 80 otters living along the coast and in the river-reservoir system.22 Small-clawed otters have been sighted on Pulau Tekong, but it is uncertain whether their habitats are in Singapore or Johor.23

Human interactions
Since the establishment of otter families in the Bishan-Ang Mo Kio Park and Marina Bay areas, otters have been regularly reported in the press and social media.24 Groups like OtterWatch also regularly report on the different otter families.25 The Otter Working Group has representatives from various organisations such as Public Utilities Board, National Parks Board, the National University of Singapore and the otter-watching community.26 There has been the occasional negative incident involving otters, for instance, in 2015 when ponds of expensive ornamental koi at Sentosa Cove were decimated by otters.27

Otters have also been used as mascots. The Agri-Food & Veterinary Authority of Singapore introduced Oscar the Food Safety Otter in 2002, “because it is a clean animal that has a habit of washing its food before eating”.28 In 2016, the People's Association made Ottie the Otter the mascot of its Project Blue WaVe environmental conservation programme.29

Variant names
Smooth-coated otter
Scientific names: Lutrogale perspicillata, Lutra perspicillata30
Malay names: Berang-berang, Memerang, Bulu Lichin31
Chinese name: hua bi ta (滑鼻獭)32

Small-clawed otter
Scientific names: Aonyx cinerea, Amblonyx cinerea33
English name: Oriental Small-clawed Otter
Malay names: Berang-berang Kechil, Memerang Kechil34
Chinese name: xiao zhao ta (小爪獭)35



Author
Timothy Pwee



References
1. Charles M. Francis, A Field Guide to the Mammals of South-East Asia (London: New Holland, 2008), 281. (Call no. RSEA 599.0959 FRA)
2. Francis, A Field Guide to the Mammals of South-east Asia, 281; Nick Baker and Kelvin K. P. Lim (co-ordinators), Wild Animals of Singapore: A Photographic Guide to Mammals, Reptiles, Amphibians and Freshwater Fishes (Singapore: Draco Publishing & Nature Society (Singapore), 2012), 131. (Call no. RSING 591.95957 WIL)
3. Baker and Lim, Wild Animals of Singapore, 163; M. Guerrini et al., “Spatial Genetic Structure in the Vulnerable Smooth-coated Otter (Lutrogale perspicillata, Mustelidae): Towards an Adaptive Conservation Management of the Species,” Raffles Bulletin of Zoology 68 (17 August 2020): 719–34.
4. N. Sivasothi and Burhanuddin Hj. Md. Nor, “A Review of Otters (Carnivora: Mustelidae: Lutrinae) in Malaysia and Singapore,” Hydrobiologia 285: 151; Lea Wee, “Mad about Otters,” Sunday Times, 24 July 2016, 6. (From NewspaperSG)
5. Francis, A Field Guide to the Mammals of South-east Asia, 281; Baker and Lim, Wild Animals of Singapore, 131.
6. Sivasothi and Nor, “Review of Otters,” 157–58.
7. Baker and Lim, Wild Animals of Singapore, 153.
8. Sivasothi and Nor, “Review of Otters,” 155.
9. Baker and Lim, Wild Animals of Singapore, 153.
10. Sivasothi and Nor, “Review of Otters,” 154.
11. Baker and Lim, Wild Animals of Singapore, 154.
12. Baker and Lim, Wild Animals of Singapore, 154.
13. Boonsong Lekagul and Jeffrey A. McNeely, Mammals of Thailand (Bangkok: Association for the Conservation of Wildlife, 1977), 561. (Call no. RSEA 599.09593 BUN)
14. Lekagul and McNeely, Mammals of Thailand, 533, 556, 561.
15. Syed Ainul Hussain and Binod Chandra Choudhury, “Distribution and Status of the smooth-coated Otter, Lutra Perspicillata in National Chambal Sanctuary, India,” Biological Conservation 80, no. 2 (1997): 199–206. (From NLB’s Web Archive Singapore)
16. Serge Larivière, “Amblonyx Cinereus,” Mammalian Species, no. 720 (30 July 2003):1–5; Yeen Ten Hwang and Serge Larivière, “Lutrogale Perspicillata,” Mammalian Species, no. 786 (20 December 2005):1–4. (From JSTOR via NLB’s eResources website)
17. Lekagul and McNeely, Mammals of Thailand, 556; Yeen and Larivière, “Lutrogale Perspicillata,” 1–4.
18. Lekagul and McNeely, Mammals of Thailand, 561.
19. Sivasothi and Nor, “Review of Otters,” 155.
20. Heeeun Monica Kim, “Lovable Lutrines: Curated Nature and Environmental Migrants in the Ottercity,” in Eating Chilli Crab in the Anthropocene: Environmental Perspectives on Life in Singapore, ed. M. Schneider-Mayerson (Singapore: Ethos Books, 2020), 42. (Call no. RSING 304.2095957 EAT)
21. Kim, “Lovable Lutrines,” 43; Goh Sui Noi, “Going, Going… the Oriental Small-clawed Otter,” Straits Times, 16 May 1994, 3. (From NewspaperSG)
22. Kim, “Lovable Lutrines,” 43–44; Goh, “Oriental Small-clawed Otter.”
23. Goh, “Oriental Small-clawed Otter.”
24. Kim, “Lovable Lutrines,” 43–44; Goh, “Oriental Small-clawed Otter.”
25. Wee, “Mad about Otters.”
26. Toh Ee Ming, “Native Fauna in an Urban Jungle,” Today, 9 August 2016, 12. (From NewspaperSG)
27. Samantha Boh, “Did Otters Eat Koi Worth $80,000?Straits Times, 9 July 2015, 1. (From NewspaperSG)
28. Agri-food & Veterinary Authority of Singapore, FY2002/03 Annual Report (Singapore: Agri-Food & Veterinary Authority of Singapore, 2003), 13–14 (Call no. RCLOS 338.1095957 AVASAA-[AR]); Lynn Seah, “Keeping Food Safe and Good,” Straits Times, 31 July 2009, 64. (From NewspaperSG)
29. Janice Tai, “Cleaner Water Bodies Drawing More Otters Here,” Straits Times, 27 June 2016, 7. (From NewspaperSG)
30. Baker and Lim, Wild Animals of Singapore, 153.
31. Gathorne Gathorne-Hardy (Earl of Cranbrook), The Wild Mammals of Malaya: And Offshore Islands Including Singapore. Singapore: Oxford University Press, 1969), 86. (Call no. RCLOS 599.09595 CRA)
32. J. L. Harrison, An Introduction to Mammals of Singapore and Malaya (Singapore: Malayan Nature Society, 1966), 223. (Call no. RCLOS 599.095957 HAR)
33. Baker and Lim, Wild Animals of Singapore, 154.
34. Gathorne-Hardy, Wild Mammals of Malaya, 87.
35. Harrison, Mammals of Singapore and Malaya, 224.



Further resource
B Moretti. et al., “Phylogeography of the Smooth-coated Otter (Lutrogale perspicillata): Distinct Evolutionary Lineages and Hybridization with the Asian Small-clawed Otter (Aonyx Cinereus),” Scientific Reports 7 (2017): 3–10.



The information in this article is valid as of September 2021 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.


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