The purpose of this article is to re-assess the status of two of the established’ Asian Ratsnakes - Elaphe taeniura friesei and Elaphe helena - and to update enthusiasts regarding their progress. For those readers for whom they represent new species, I hope you enjoy being introduced to them. Perhaps you will view them as interesting and worthwhile additions to your collections.
I am pleased to find that the interest in Ratsnakes from S.E. Asia is continuing at present. Many hobbyists consider them to be exciting to the more familiar N. American and European species. This in turn has resulted in significant recent breakthroughs with certain Asian species. Each year there are more species which are becoming established as reliable captives and breeders, particularly by European herpetologists. Although there remain certain species which persist in frustrating all attempts to establish them, hopefully this list will continue to be reduced by the perseverance, dedication and skill of those who have been fatally smitten by the allure of these splendid animals.
Elaphe taeniura friesei (1926)
The Taiwan Beauty Snake or Stripe Tailed Racer (E. t. friesei) was among the first Asian ratsnakes to quicken my pulse. Some years later I gained tremendous pleasure and satisfaction from working with these spectacular colubrids. They appeared so exotic when compared with the Elaphe sp. which were commonly available. I resolved to acquire a group, which in turn resulted in a lengthy and frustrating search for breeders who could supply specimens.
My first specimen was secured in 1986 and shortly afterwards I was fortunate to acquire two more. In the years that followed small numbers regularly imported from the continent and more hatchlings were obtained. As a species, the hatchlings proved to be remarkably robust compared to the general reputation that Asian snakes have gained. They fed and grew at an astonishing rate; one male grew to nearly 2m in just twelve months.
However, acquiring true pairs proved difficult and this frustrated initial breeding attempts. The loss of a reliable, breeding female during hibernation also interrupted the breeding programme for this species. Happily, specimens are now easily obtained and these proved to be temporary setbacks.
Initially E. t. friesei was the only member of the Elaphe taeniura complex which was available as captive bred stock. It is now evident that most of the ssp. are being bred on a regular basis throughout Western Europe. E. t. taeniura, E. t. vaiilanti, and E. t. yunnanensis were all readily available at the recent European Snake Day (an annual event hosted by the European Snake Society in Holland). E .t. ridleyi, unfortunately remains a form which is desirable and elusive to the same degree. The best examples of the ssp. have clear blue/grey heads, pale yellow/brown bodies with black and white striped tails. They are rarely available and captive-raised specimens are at a premium.
The range of E. taeniura extends widely from northern China, southwards through Vietnam, Thailand and Malaysia and the Riukiu islands off Japan mark the extreme edges of its distribution.
The status of the subspecies within the complex is currently being reviewed. However, it seems possible that at least eight forms will be recognised, perhaps more. All are large, robust and attractive snakes. They are mainly differentiated by geographical distribution, scale counts, markings, colour, head shape and tongue colour.
E. t. friesei is the largest member of the complex, attaining lengths in excess of 2.5m and has the honour of being acredited as the largest member of the Elaphe genus. It is found exclusively on the island of Taiwan. It is a common and familiar snake, being found throughout the island and in a wide variety of habitats. It is often found close to human habitation and it is easy to imagine this species as a valuable controller of vermin. It is also a frequent item on local menus (don’t try Dragon and Tiger soup - snake and cat) and regularly contributes to the leather industry of the island.
My personal opinion is E. t. friesei, E. t. yunnanensis E. t. ridleyi represent the most attractive and desirable examples. However, beauty is in the eye beholder. E. t. friesei possesses a somewhat triangular head, with a blunt snout. A prominent black line passes through the eye, extending to the posterior temporal at the corner of the mouth. The head is coloured olive yellow/olive grey and the head shields are large, smooth and glossy. The supralabials are a distinctive pale cream and contrast sharply from the upper head. The tongue is a beautiful blue with black stripes, reminiscent of the Red Tailed Racer (Gonyosoma) Elaphe oxycephela.
The body is again olive yellow to olive grey with a smooth, glossy appearance. The dorsal markings start at one - one and a half head lengths from the neck. This distinguishes E. t. friesei from the superficially similar E. t. vaillanti as this ssp. has markings which begin at three head lengths from the neck. Certain scales have reddish tints if examined closely.
The markings of E. t. friesei are very complicated and difficult to describe. They consist of numerous black markings which modify and alter along the body length. Dorsally these assume “dumbell” or butterfly” shapes which gradually degenerate into a ladder” type of arrangement as the tail is approached. The tail is patterned in dramatic black and lemon yellow stripes. Laterally there is a complicated configuration of squarish blotches and spots. Some of these contain white or yellow centres, forming a series of ocelli. In the most spectacular specimens these ocelli are numerous and very pronounced.
The ventral surface is cream/white, becoming progressively more yellow as the tail is approached. There is also an increase in black/grey chequered markings. The anal scale is divided and the subcaudals number 104-118.
My specimens have displayed two colour phases. One is predominantly yellow with black markings; the second is more typical olive grey with black, white and yellow markings. Both phases are very attractive.
My specimens are housed in a vivarium measuring 1.9m/1.5m/lm (L/W/H). This unit can be divided to segregate the sexes. It features a concealed floor/drawer system which suits this secretive species ideally. The snakes spend most of their time in the drawers. The daytime temperature ranges between 25C and 28C, with a slight night time drop.
The hibernation regime for E. t. friesei is identical to that provided for other temperate Elaphe species in my collection. They receive a 3 months cooling period to 10-12C. In my experience, hibernation is essential for males, but less so for females, if breeding is to be successful.
Food is offered in the drawers and E. t. friesei are avid feeders. I generally maintain my specimens on one adult rat per 14 days, although gravid females are fed more extensively. Food fights are rarely witnessed, but caution should be used in this respect if specimens are housed together.
Breeding is not difficult to achieve with well conditioned adults. After hibernation specimens are warmed gradually and fed. After their first slough females are introduced to the males vivaria on a regular basis. Courtship and copulation follow the same pattern as other Elaphe sp. with males pursuing females until they successfully mate.
Matings typically occur throughout March - May, with eggs being laid 6 - 8 weeks later. Other breeders have recorded clutch sizes of 8 - 9, however I have received as many as 14 eggs, although some were infertile. The eggs are large - 47mm-6Omm by 32mm and weigh, on average 43.3g (heaviest personally recorded - 46.5g). Each egg had a slightly pink tint and a rather thick, tough shell.
An account of breeding E. t. friesei in my own collection conformed to the following pattern. After a three month hibernation period and a conditioning diet of young adult rats, the female was introduced to the males vivaria on a regular basis from May onwards. This is later than data from European breeders. Courtship and copulation were frequently witnessed and by July the female was displaying signs that she was gravid.
She continued to feed, but on smaller items and small faeces were frequently deposited in the vivarium. Her posterior section began to swell noticeably. Eventually all feeding ceased in August and her girth continued to expand. Following a post-coital slough the female began frantically to search the vivarium. At this time a nesting box was provided. This consisted of a large, lidded plastic bucket which was half filled with damp vermiculite.
This was visited more and more frequently until 13 eggs were laid on 5th September. Two of these were obviously infertile, and a further egg (the fourteenth) was retained and was clearly visible through the gaping cloaca. Warm water soaking and gentle manipulation did nothing to remedy this situation, therefore a small incision was made in the shell and the contents were gently expelled. The collapsed shell was then easily removed.
Throughout incubation, the eggs developed intricate crack lines. I have no explanation for this and no other species eggs were similarly affected, despite being incubated under identical circumstances. At 28C the first egg hatched on 8th November, 64 days after being laid, the others had all hatched within the next three days.
The hatchlings measured approximately 40cm and were identical, if somewhat darker, replicas of their parents. Their weights were between 22.9g and 31.4g. resumed feeding on mice appropriate size shortly shedding their neonatal skins presented no problems in rearing.
Elaphe helena (Daudin 1803).
The trinket snake (Elaphe helena) is another Asiatic ratsnake which I have enjoyed working with over recent years. Although not as “showy” as the previous species, it has a discrete beauty and displays some fascinating habits. Indian reptiles are seldom available to enthusiasts due to this continents strict conservation laws and E. helena constitutes an interesting and welcome representative from this fertile herpetological region.
E. helena ranges through much of India, particularly in coastal regions, as well as occurring in Bangladesh, Nepal, S. Pakistan and on Sri Lanka. Two forms are recognized which are often referred to as Eastern and Western phases. The Eastern’ phase is the most common and is characterized by four dark lines on the neck. In addition the anterior cross bands are incomplete, often forming a dorsal viperine stripe.
The “Western” phase (E. h. malabarica?) is characterised by complete, crossbands and possesses a distinctive light collar. This second form is extremely elusive and I am not aware of any living specimen currently maintained in captivity. This form is restricted to the Western Ghats.
My specimens are of the “Eastern” form. The head is brown, with an oblique black line from the eye to the 7/8th supralabial. The supralabials themselves and the chin are whitish. The body is attractively marked in various shades of brown, with black and white ocellated anterior crossbands which are most conspicuous on the sides. these resemble charm bracelets and it is easy to see how its common name was derived. These crossbands become less distinct as the tail is approached. The tail itself is patterned with black and brown longditudinal stripes. The scales are small, smooth and glossy, with a velvety sheen.
The ventral surface is clean white or ivory-coloured . Certain specimens, especially females, can develop a beautiful apricot or peach hue to the ventral scales which complements the rich brown dorsal tones perfectly. The anal scale is undivided. I have found that the subcaudal counts are extremely variable, numbering anything between 73 to 100+. Females tend to darken with age and the crossbands become less distinct, but they remain attractive animals, nonetheless.
There are many interesting features concerning E. helena. One of these is the pronounced sexual dimorphism which exists regarding size. Males are noticeably smaller than females, as well as being more brightly coloured. This difference is not evident as hatchlings, only as maturity is approached does it become apparent. Females reach lengths in excess off 150cm, males seldom exceed 90cm.
The body tone of E. helena is much stiffer than is normally associated with ratsnakes. They also have a tendency to rest bunched up into little curves. This gives them a rippled effect, which is also characteristic of other Asiatic ratsnakes, e.g. E. radiata, E. taeniura etc.
In its natural state E. helena will often enter houses and gardens also. It has a wide variety of prey items including mammals, birds, amphibians, lizards and snakes. Juveniles have even been observed to eat crickets in captivity.
E. helena is easily catered for in captivity, requiring similar conditions to most other colubrid species. They do not appreciate extremes of temperature and a thermal gradient within the vivarium is recommended, if sloughing is a problem, then increased humidity at this time is beneficial. I usually provide a box of damp sphagnum moss, or place the animal in a damp cloth bag overnight if pieces of sloughed skin are still attached.
The vivarium does not need to be large. My specimens are housed in a concealed floor/drawer designed unit, the overall dimensions being 60 by 40 by 45cm (L by w by h). E. helena can also be maintained successfully on a shelving/heating strip system. Wood shavings, newspaper and coconut compost have all been employed as substrates without problem.
Food is offered in the drawers and females are the more aggressive feeders. As they grow they prefer to accept food from tongs, juveniles are usually undemanding in this respect. Half-grown mice are the normal diet, but items which are too big may be refused.
E. helena is a tropical species and hibernation is not necessary to breed them successfully. I have heard that certain breeders have provided them with a slight cooling period without problem, however other breeders have experienced losses through hibernation.
As previously stated, it is not necessary to hibernate E. helena and multiple clutches are produced throughout the year. The average number of clutches per year is four, with 7 or 8 eggs in each clutch. Another fascinating trait of this species is it’s remarkable ability to store sperm (amphigonia retarda). The record breeding performance for one specimen is seven clutches is one year, five of which were the result of a single mating (J. Weir - personal communication).
Because breeding is continuous, gestation dates are difficult to assess. In addition, due to the “torpedo” shaped eggs females may not be obviously gravid. Feeding also continues throughout gestation. Therefore it is advisable to provide a nesting box as a semi-permanent feature of their vivarium. In this respect it is important to maintain standards of hygiene, particles of faeces or pieces of sloughed skin will quickly become a breeding ground for pathogens in the warm, damp medium.
Males commonly refuse all food in the presence of an ovulating female. In order to ensure that males receive sufficient nourishment, I separate them from the females on a regular basis, re-introducing them after the females slough.
Under these conditions, courtship was observed in March, with seven eggs being laid in April, 39 days later. The eggs were elongate, measuring 40mm by 18mm on average, and weighing between 9-l0g each (heaviest recorded - 10.7g). Clutches are particularly common in September and December. These hatched successfully between 70-72 days after being incubated at 28C.
The hatchlings measured around 25cm long and weighed between 7-9g each. They were beautiful, bright replicas of their parents, having soft yellow heads and large appealing eyes. The hatchlings of Asiatic Elaphe often resemble the adults in pattern and colour, this differs from European and American Elaphe where they undergo a change of colour as they mature.
Their neonatal skins were shed after 10 days and feeding resumed on pre-killed mice thereafter. Raising the hatchlings proved to be totally unproblematic.
Two further clutches of eggs were laid from a subsequent mating which occurred in early June. The eggs were laid on July 5th (7) and September 6th (7). The hatch rate for both these clutches was 100% and a good sex ratio for all three clutches was achieved. The incubation period for these two later clutches was slightly shorter, with all eggs hatching between 65-67 days.
It is worth noting that E. helena will attempt to mate at an early age - I had one male trying in earnest at just 9 months old.
CONCLUSION & SUMMARY
E. t. freisei and E. helena both represent rewarding and undemanding vivarium subjects. Breeding is easily accomplished with well conditioned adults in both species.
Hibernation is recommended as a pre-requisite for breeding E. t. friesei, although this practice is less critical for females, hibernation is not recommended for E. helena, where multiple clutches are produced throughout the year.
Both species are bred regularly in captivity and captive born specimens are readily available, particularly in Western Europe. Inbreeding may eventually become a cause for concern due to the small initial captive populations. Juveniles of both species are easy to cater for and rear to breeding size.
E. helena exhibits a pronounced sexual dimorphism and is represented by two distinct forms. E. t. freisei females also tend to be larger than males, but this trait is less obvious. E. taeniura is represented by a large number of sub-species, which range throughout much of S. E. Asia.
Both species represent a viable alternative to New World Elaphe species and can be warmly recommended to ratsnake enthusiasts.
Bibliography / Additional Reading
POPE, C.H. (1935) The Reptiles of China.
SMITH, M.A. (1931) The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo Chinese Subregion. Vol III: Reptilia and Amphibia: Serpentes.
KUNTZ, R.E. (1963) The Snakes of Taiwan. U.S. Naval Medical Research Unit, No. 2.
DANIELS, J.C. (1983) The Book of Indian Reptiles. Bombay Natural History Society.SCHULZ, K.D (1987) Elaphe taeniura (Cope 1861). Asiatic Ratsnakes of the Elaphe Genus - Part VIII. Sauna, W. Berlin. Also appears in Litteratura Serpentium (English Edition) Vol. 7, No.1 Feb 1987.
SCHULZ, K.D. & NIEHAUS, G. (1987) Elaphe helena (Daudin1803). Asiatic Ratsnakes of the Elaphe Genus - Part Xl. Sauna, W.Berlin.
BROER, W. & ENGLEHARDT,M. (1987) Haltung und Zucht Einer Selten Importen Schlange: Elaphe helena (Daudin 1803). Salamandria 17, 1/2. W. Germany.
De SILVA, A. (1990) A Colour Guide to the Snakes of Sri Lanka, R & A Publishing Ltd U.K.
STEEHOUDER, T. (1989) Breeding the Taiwan Ratsnake, Litteratura Serpentium (English Edition) Vol. 9 No. 6 Dec 1989.
SMITH, T. (1987) Asiatic Colubrids - Part 1. The Herptile, Vol 12 No. 4.
SMITH, T. (1988) Elaphe taeniura. The Herptile, Vol 13 No.
SMITH, T. (1990) Elaphe helena. The Herptile, Vol 15 No.1.
WEIR, J. Pers. Comm.
About the Author
Trevor Smith is an eminent herpetologist who has done much work in keeping and breeding snakes, with a particular emphasis on Asian Ratsnakes. He was the first person in the UK to breed both E. t. friesei and E. helena: He also worked on some of the illustrations for The Monagraph by Klaus-Dieter Schulz
Reproduced with the kind permission of Chris Newman, The Reptilian Magazine