Tuesday, 12 March 2013

Smooth-coated Otters


          Smooth-coated otters (Lutrogale perspicillata) is the only representative of the genus Lutrogale. It is classified as vulnerable as its natural habitats become degraded. The species is distributed form southern Pakistan, parts of India to South-East Asia. There is a disjunct population in Iraq.

The geographic range of Smooth-coated Otters

Smooth-coated Otters are relatively large for otters, weighing from 7 to 11 kilograms (15-24lb) and measuring 59-64 centimeters (23-25inches) in head-body length with a 37-43 centimeter tail (15-17in). Compared to other otters they have a more rounded head and a hairless nose in the shape of a distorted diamond. They have a flattened tail, strong short legs with large webbed feet and strong claws. The fur is dark to reddish brown.

Smooth-coated Otters are a large-sized otter species

They have hairless noses and rounded faces

......and short reddish brown fur

Smooth-coated Otters are found in areas where fresh water is plentiful….wetland, seasonal swamps, rivers, lakes and padi fields.  They are equally at home in the water or on land.

Smooth-coated Otters are excellent swimmers

............but are equally at home on the land

These otters are social and hunt in groups. They are mainly diurnal and rest up during the heat of the day. They spent the night in dens dug in dense vegetation, under tree roots or among boulders. They use scent to communicate both within their species and with other animals. Each possess a pair of scent glands at the base of the tail which are used to mark objects near feeding areas….called sprainting. They communicate through vocalizations such as whistles, chirps and wails. They eat mainly fish and can sometimes hunt cooperatively.

Smooth-coated Otters marking territory on a cleared patch of land

They have scent glands at the base of their flattened tails

Typical sprainting behavior

Smooth-coated Otters form small family groups of a mated pair with up to four offspring from pervious matings. Copulation occurs in water and lasts less than a minute. Up to five pups are born after a gestation period of 60-63 days. The pups are weaned at about three to five months and reach adult size after a year and sexual maturity at two to three years.
This otter species has a very careful approach to moving into new territories or keeping surveillance on perceived threats. There always appears to be one pair of eyes looking for possible danger or many pairs looking at every point of the compass.

Reconnaissance in the grass

.....or in every direction in the water

In Penang, Malaysia I was able to observe and photograph Smooth-coated Otters in two locations; in the estuarine area near Byram and in the coastal region near my home at Seri Tanjung Pinang. The former group seemed to number around nine individuals while the latter observations centered around 3-4 pairs mainly, although one morning in the pre-dawn I saw about nine individuals ranging from full size adults to four small pups. On a number of occasions  I have seen otters disappear in clefts between rocks on the breakwater adjacent to the promenade. Boating friends also report they are frequent visitors to the marina and possibly have a den with the infrastructure of the wall. The local Chinese call them 'sea dogs' and indeed there have been reports of them playing with domestic dogs in the shallows of a nearby popular dog-walking beach.

The Byram family were observed within the red lines around an estuary 

The mouth of the estuary at Byram (with rainbow)

Five of the nine members of the Byram family

The red line marks the area where the Straits Quay pairs were photographed

The land/sea interface where otter pairs make their dens (holts)

The breakwater rocks adjacent to the Promenade provide dens for otters.

The otters are also frequent visitors to the Marina

The pairs cooperate in hunting by herding fish into the shallows

Large fish are shared but they eat individually


               What is the most fascinating aspect of Smooth-coated Otter behavior is the closeness of their relationships. They are constantly looking out for each other and for any approaching danger. One pair had come separated and the female was particularly anxious to find the male who was about 70 meters away. When she sighted him she practically ran across the water to be near him. 

An excited female races towards her partner

Once united they embrace briefly

          They are consummate fishermen and seemingly need to just fall into the water catch somewhat large fish. On several occasions I have seen the Straits Quay Otters come up with large catfish and what looked like a small shark or dogfish. They do not immediately share their catch but will hand over half the catch to a partner. It would be too dangerous having two sets of those awesome teeth converging along the body of a fish. Several otters were also observed herding shoals of small fish until they all took a trophy. Local fishermen occasionally use long nets to catch fish and a man on each end of the net is up to his neck in water and his feet wedged into soft mud is not in a position to defend his catch. I have seen several opportunistic otters  to raid the middle  of the net for captured fish with the immobile net-holders managing to see the humorous side of things. 


Heads and tails are removed from the fish before eating

Smooth-coated Otters are adept fishermen coming up with fish in heavily fished waters

Large Catfish provide a good feast near Straits Quay

......and so do small sharks

Sometimes they gang together and herd the smaller fish before getting their rewards

 Like most animal young the immature otters appear to have a sense of fun. At low tide in the Byram estuary the flat banks are coated with a layer of oozing mud. The otters were observed to deliberately toboggan across the slight incline before retracing their steps to repeat the fun.

They younger otters seem to enjoy tobogganing in the mud at low tide
Dave Bakewell, a local bird and ecology expert indicated to me the he took a video in close proximity to Straits Quay showing an otter mud-sliding in order to catch mudskippers. The video can be seen  here ,
A local resident also indicated that otters has also been observed at a nearby beach interacting with dogs that are often walked on the beach. Shown at this link
There is also a second video of a dog swimming in the water and an otter popping up either side of him
The Smooth-coated Otters are essentially an estuarine species but seem to be adapting well to a salt water environment and to adapt to the local environment.

5 comments:

  1. Outstanding post, Graeme! You are just as good wiith mammals as you are with birds.

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  2. Agree with Mun - wonderful images and informative text Grame. Thanks! I took a video of one of the Tanjung Tokong otters mud-sledding some years back. The quality is not great, but the otter's antics are hilarious! It's here: http://www.youtube.com/watch?feature=player_embedded&v=Rx6fXDbMrMI Have you seen this behaviour?

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  3. Dr. Graeme, I'm a Korean writer, Ju Hee Lee. I'm writing a book about otter. I want to use your great pictures of smooth coated otter in my book. How can I get it? Please email me! superuomo@gmail.com

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  4. I was really pleased to see this page. The otters here resemble ones I saw at Kuantan. I'd appreciate very much if you could have a look at my video at http://youtu.be/NqekS0o3Bkw. to let me know if these are also smooth coated otters. I had a message saying they are not sea otters but no other comment. I watched these otters for at least 30 minutes.

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  5. Hi Grame, my name is Sadie Coles, I am a researcher for the BBBC Natural History Unit in Bristol, UK. I am currently working on a three part series about Thailand’s wildlife and culture. We are looking into filming smooth coated otters in the north of Thailand and I wondered if you could help me understand the behavior of the otters in March? my email is sadie.coles@bbc.co.uk feel free to drop me an email if you can help, thank you, Sadie

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