Singapore’s waterways have seen a massive transformation over the past few decades. From being highly polluted, filled with trash and sewage as the Singapore River was in the late 1970s, Singapore’s waters have never been cleaner after the launch of the Clean River Campaign in 1977 (Xu, 2019). Since then, ecological conditions have improved, making urban waterways habitable  for otters, semi-aquatic mammals that have well-adapted to Singapore’s urban environment. Today, as many as 70 otters can be found in Singapore, thriving in the canals and rivers that link the country’s various water bodies, and are often sighted much to the surprise of members of the public (Turrell, 2020). In fact, these charismatic mammals have gained much popularity among local followers and even attracted fans across the globe (Ishak, 2020)!

The two main species of otters that can be found in Singapore (Xu, 2019)

So how did these otters get here and settle in Singapore’s urban environment? Were they originally in Singapore or did they immigrate from elsewhere? 

Historically, otters used to be found in Singapore in the 1960s. However, due to habitat disruption and water pollution from land reclamation and urban development, otter populations declined and eventually disappeared sometime between 1970 to 1980 (Sivasothi & Nor, 1994). As water quality improved after 1977, otters began to return to the waterways of Singapore possibly when a population swam across the Johor Straits from Malaysia to the North side of Singapore. Thereafter, sightings have been noted in Sungei Buloh Wetland Nature Reserve, Ang Mo Kio (AMK)-Bishan Park and even Marina Bay (Xu, 2019)!

Otters spotted along a path in Marina Bay (Photo credits: Bernard “Ottergrapher” Seah)

Why are otters so successful in Singapore’s urban environment?

There are three main reasons why otters have been able to adapt and establish populations successfully in Singapore.

1. Otters mainly eat fish (piscivorous), but they are also able to accommodate a wide diet which includes prawns, crabs and even amphibians (Theng et al., 2016). As urban waterways are abundant with fish, particular exotic fish species such as Tilapia, they have been able to support the local otter populations that we see today (AMK-Bishan population, Marina Bay population, etc). In addition, most of the waterways in Singapore are connected, allowing otters to swim from one place to another in search for more food!
2. Otters are semi-aquatic and thus they require dry land for grooming (rolling on grass/sand/soil), resting, sleeping and even seeking refuge from disturbances in vegetation (Theng & Sivasothi, 2016). As such, riparian zones are highly important for the survival of otters. Since the landscape of most urban waterways are gently sloping, such as that of AMK-Bishan Park and Marina Bay, as opposed to being vertical concrete walls, they allow for otters to access land from the waterways easily. Additionally, otters have been noted to exploit urban sites such as canals as holts (resting sites), which are normally holes dug in the ground by otters in the wild (Turrell, 2020). This level of adaptability to utilise urban structures and waterways has therefore enabled them to be successful in Singapore.
3. Lastly, there are no natural predators in urban waterways that threaten their survival such as wild/stray dogs. Otters are hence the apex predators in urban waterway habitats (Theng et al., 2016). Plus, humans love otters – who would want to remove them from our waterways? (Except for several occasions when otters sneaked into a residential area and devoured $80,000 worth of koi fish, but that is another topic for discussion in itself. More about it here)

A young otter pup with its catch of the day: a crayfish (Photo credits:  Bernard “Ottergrapher” Seah)

As such, these are the reasons why otters are able to make a comeback in Singapore and adapt to the country’s urban waterways so well. Otter populations have been doing so well that recently, the AMK-Bishan family has clashed with the Marina Bay family in Kallang Basin to expand their territory! (video of their ‘violent’ gang fight below)

Hopefully, the otter population will continue to grow bigger in future and bring more joy to Singaporeans as humans and otters co-exist together.

Cheers,

Keith

 

References

Ishak, N. S. (2019, January 14). Singapore otters a hit overseas. Retrieved on 18 April 2020, from: https://www.tnp.sg/news/singapore/singapore-otters-hit-overseas

Sivasothi, N. & B. H. M. Nor (1994). A review of otters (Carnivora: Mustelidae: Lutrinae) in Malaysia and Singapore. Hydrobiologia, 285: 151-170.

Theng, M. & N., Sivasothi & Tan, H. (2016). Diet of the smooth-coated otter Lutrogale perspicillata (Geoffroy, 1826) at natural and modified sites in Singapore. The Raffles Bulletin of Zoology. 64. 290-301.

Theng, M. & N., Sivasothi (2016). The Smooth-Coated Otter Lutrogale perspicillata (Mammalia: Mustelidae) in Singapore: Establishment and Expansion in Natural and Semi-Urban Environments. IUCN/SCC Otter Specialist Group Bulletin. 33. 37-49.

Turrell, C. (2020, March 10). Cheeky otters are thriving in Singapore-and adapting quickly to big city life. Retrieved on 18 April 2020, from: https://www.nationalgeographic.com/animals/2020/03/urban-otters-singapore-wildlife/

Xu, K. (2019, March 8). The otter side of Singapore. Retrieved on 18 April 2020, from: https://kontinentalist.com/stories/the-otter-side-of-singapore