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This article focuses on some of the behavioural traits & quirks that I have observed over the last 18 months of keeping this species including hearing four of them when housed together make a sound not too dissimilar to a cat, as well as the general maintenance in captivity over this period from hatchling and a little natural history.
 


INTRODUCTION

In July 2007 I acquired 4.4 hatchlings from Crystal Palace Reptiles which were bred by Tula Exotarium in Russia. One pair went to a friend's collection. One of the females that I kept was hypermelanistic and the rest were the striped form. These were one of the first times, if not the first, that this species was available in the UK as captive bred; the same year several more from the same sources were offered for sale.

Natural History

Distribution for the nominate species is throughout the Lesser Sundra islands, Klaus Dieter-Shultz (1996) states the following islands being inhabited by Coelognathus s. subradiatus: (Lombok, Sumbawa, Komodo, Flores, Endeh, Alor, Wetar) Sumba, Rotti, Samao and Timor (= terra typica).

The subspecies C.s.enganensis occurs only on the Island of Engano off the south coast of Sumatra.

A eurytopic species that is found from 0-1200m. above sea level, it is found in tropical forests, steppe like landscapes along the coastal regions and in coconut plantations with its preferred habitat being noted as open brush areas. In the wild they eat mainly rodents and birds as adults, but young snakes have a preference for lizards.

Patterns and colour vary from island to island and also within populations as does size. Schulz divided them into two groups, those from the Indonesian Islands of Roti, Semau and Timor reaching no more than 120 - 160cm, whereas those from the Lesser Sunda islands (Adonara, Alor, Endeh, Flores, Lombok, Rintj, Sumba, Sumbawa and Wetar) grow larger up to 170cm with some individuals obtaining 220cm.


CAPTIVE CARE

The first six months.

Each hatchling was initially set up individually in small ventilated 5L tubs with a substrate of aspen a water bowl and a humid hide. They were housed on shelves which were heated from behind by a Jemp (heat) cable. The hot end was regulated to 84F with the use of a thermostat and the cooler end dropped to room temperature (approx 74-76F). The sides of the container were sprayed daily to keep humidity above 70%. After a few months I changed the substrate to kitchen towel as it was easier to feed them. Food had been placed on kitchen paper so that the snakes could not ingest any substrate, but, occasionally, they would flee with their meal into the aspen so I decided kitchen roll was the safer option.

All but one fed for the first few months every three to four days on defrosted pinky mice which were left at the entrance to their hide later progressing to fuzzy mice by their 7th meal and later small mice. The hatchling that refused initially defrosted pinkies was coaxed into eating by scenting a washed defrosted pinkie with T Rex Lizard Maker. After a few scented meals it started to accept regular unscented prey. Most would eat even when in slough; feeding presented little problems as long as the humidity was over 70%.

They seem to be very prone to dehydration at this age and will refuse food if humidity levels are not maintained. Their metabolism is very fast and pinkies could be digested as quickly as one day; even now on furred prey they defecate after approximately 48 hours.

They were very shy and handling was kept to a minimum. On the occasions that they were handled they were quite defensive and often inflated the first third of their body and took on the typical 'S' pose associated with other snakes of the genus Coelognathus . This defensive pose is nowhere as impressive as that of C. radiatus . Quite often though, they would flee rather than stand their ground.

At approximately 6 months of age they measured on average 26 inches
(66cm).

Six months to one year.

I moved them into 9L tubs at approximately 6 months of age and changed the substrate to Sphagnum peat moss. I used damp loose sphagnum moss on one side of the enclosure. This created a very humid atmosphere, often condensation formed on the lid on the cooler end. They were placed on a rack which was heated from below by a heat strip. As for hatchlings, the temperature in the hot end was 84F.

Now they have some length to them, they have started to lose their shyness, and will take food off the tongs. They started to get a really good feeding response and would often fly out the tub and constrict the mouse. Some would even catch the mouse mid air if it were thrown into the tub. They grew quickly, putting on length rather than girth in the first six months. Once taking large mice at the age of approx 10 months, two of them (male & female) really stated to bulk out, whilst the others still looked like juvenile snakes. This one pair by one year were beginning to look like adults. Their feeding regime was no different to the others but their colouration is with the larger pair being dark brown, the others, apart from the hypermelanistic which sadly for no apparent reason died, have a lot of yellow colouration to them.

At approximately 10 months of age the average length was 35 inches (89cm).

One to Two Years.

The larger pair mentioned above were moved to 33L enclosures at approximately 10 months of age; the others didn't get upgraded until they were approximately 14 months old. By this time the pair was moved into 50L enclosures.

The set up is the same as above with sphagnum peat moss used as a substrate, damp loose moss and a dry hide. They love to burrow and quite often are found under the earth on the bottom of the container. They continue to be flighty and defensive if cornered but are handleable when out with only the occasional nip given. Like C. radiatus they are very aware of their surroundings and if they are in their hide will stick their head out to see what’s going on when you approach the rack.

Two of the smaller subradiatus went on a fast for approximately 4 weeks after being moved to the larger tub; they were coaxed back into eating by offering them defrosted fuzzies. They quite happily ate 4 or five of these at a sitting and after a couple of weeks started taking adult mice again.

At 18 months of age the largest pair were just shy of four foot (122cm) and the smallest 35 inches (90cm).

At just under two years of age they now take a variety of prey items, including adult mice, weaner rats and day old chicks which they adore. Recently I tried one with a quails egg which it ate after a moment or two hesitation and lots of tongue flicking.

They are now all over the four foot mark although the thickness of their bodies varies, the darker specimens being more heavily built. Schulz mentions in his monograph a difference in body size and thickness between the different island forms. I was under the impression that all mine originated from Timor Island but it could be that the darker ones are and the more yellowy are from one of the Lesser Sundra Islands where C. subradiatus is of a smaller and more slender build.


Some noteworthy behavioural traits and quirks

The gurgling tummy

I first noticed this when they were hatchlings. When you picked them up their stomach region would feel all soft. As they got older this phenomenon became more and more pronounced and by a year old a distinct gurgling sound can be heard when picking them up. At first I thought this was my imagination and a subconscious reaction to the spongy feeling stomach,. I was showing them to a friend and asked them if they could hear the noise, to which they replied yes. I've talked to another owner of C. subradiatus and he reports the same thing. My theory is that it is some kind of defence mechanism designed to make you put the snake down. It certainly is a strange feeling to hold one whilst it’s acting this way and, accompanied by the gurgling, makes you want to put it down.

I want to suck your fingers

A friend who also keeps this species, asked me whether my Timor Ratsnakes ever sucked my fingers whilst out to which I replied with a laugh, NO. I haven't experienced this behaviour recently but after he mentioned it I remembered one of my hatchlings at approximately 3 months of age began to do it. Whenever you had him out handling him he would press into your hand like he was sizing you up for dinner then work his way to your fingers and slowly and quite deliberately start to work his way down one of them. The amount of saliva that he produced was amazing. He'd work so far down the finger then back up again and nudge the next one and start on that. Now you might be thinking had he could smell food on the hand. The answer to which is no; with their feeding response this wouldn't have been a gentle chomp down, it would be a full on I'm going to kill your hand.

I was a cat in my former life.

This has only happened the once and was the most unbelievable thing that I've ever witnessed in all the time that I've kept snakes.

I decided I would like to try to breed them as both females were, I felt, big enough. I prepared a 4 foot (122cm) vivarium for them and the idea was to put them together as a 2.2 group. The hope was that the male competition would spur them into breeding mode.

I put each one into the vivarium and a lot of blind fleeing went on with the snakes hitting the back wall then rising up it. I was kneeling on the floor watching them when I heard a wheezing sound thinking it was perhaps me as I was just recovering from a lung infection I took no notice at first. The snakes calmed down after a few minutes and lay in the vivarium with their heads raised off the ground; the noise coming from them was just incredible. Imagine four hungry cats meowing at your feet, that was what was happening in the vivarium, four subradiatus making a raspy sounding meow. I was holding my breath, listening for my own chest to be the culprit, but no, it most definitely was coming from the vivarium. This chorus lasted for a good minute, they then seemed to relax and only the occasional noise could be heard as the males became aware of the females presence and a copulatory chase ensued. All became quiet except for the usual mating thrashing.

Good table manners

As they got older and more confident they began to take food from the tongs; I've already mentioned above about them constricting the food and also catching it mid air. I would now like to mention the chewing motion; they seem to chew into the mouse and have also at times headed off with it in their mouth, head held high, and shook it, smashing it into the substrate or the side of the vivarium. Another peculiarity witnessed at feeding time is the way they attack their food. When it is placed in the vivarium they will come out from the hide, head straight towards it then attack it as if it's alive and, more times than not, constrict it whilst chewing down on it. Like C. helena and C. radiatusthey will also multiple constrict food items if presented with two or more, feeding on one whilst the others are held firmly in the coils.

Conclusion

I find this species one of the most fascinating in my collection, behavioural wise, they are so quirky and never cease to amaze me. Intelligent and alert they make for a wonderful vivarium subject to observe. What they lack in the looks department, being quite drab in comparison to say the porphyraceus clan, they make up for with their personalities.

 



If your observations of this species match those of mine, so that I don’t think I’m going crazy, I would love to hear about them on the forums or drop me a PM. I'm also interested in hearing about other observations keepers have had that don’t reflect mine.

Thanks to Gidi Van de Belt and Rob Kool who both offered invaluable help in the early days of keeping these as I was struggling to find any information besides what was in the *'Bible'.
 


References

* Schulz, Klaus-Dieter. 1996. A monograph of the colubrid snakes of the genus Elaphe Fitzinger.

This site has information on the following genera of Ratsnakes ... Spilotes, Spalerosophis, Ptyas, Zamenis, Elaphe, Rhinechis, Senticolis, Pseudelaphe, Pantherophis, Bogertophis, Orthriophis, Gonyosoma, Oreocryptophis, Oocatochus, Euprepiophis, Coelognathus, Archelaphe