of Wagler's Vipers in captivity is possible and not too difficult
once the animals are healthy and stress (induced by cagemates or otherwise) is avoided.
The image below depicts an adult Sumatran female copulating with
an adult male. This behavior can be stimulated in captivity by simulating
heavy rainfall during certain months of the year, for instance during
October to December in the case of southern Thai or western Malaysian
can occur at any time of the year if male and females are kept together
in a container. However, keeping several snakes permanently together
can only be recommended in a large container, providing
enough resting and hiding places for each individual snake. These
vipers are solitary animals. Especially females do not tolerate each
other very well, and they do not tolerate males during certain periods.
This may be become obvious by an inferior animal losing appetite in
presence of a superior, but can also result in open aggression involving
If cages are small (e.g. 60x90x40, LxHxD[cm]), males are kept solitary and separate from
females for most of the time. In case of Thai and western Malaysian
animals, August to February is suitable period to try breeding.
A male that has been kept solitary for a while usually mounts a female
immediately once placed into a container together with her. It starts
to make jerky movements and tries to get a grip of the female's tail
in order to position its cloaca close to hers (see photo above). The
copula may last many hours, and can be repeated various times in the
weeks to follow. Females are usually quite lethargic and tolerate
all of the male's attempts. Should there be signs, however, that the
female rejects the male, the latter should be removed immediately.
are some climate charts of various locations in Southeast Asia that
could be helpful for designing the right climatic conditions in a
container throughout the year.
length of the gestation period is difficult to determine exactly,
because not every copulation will result in fertilization. Furthermore,
a single insemination by a male viper may be sufficient to induce
offspring for two consecutive years. We have observed this especially
with females from the Philippines. Usually the gestation period of
Thai, Western Malaysian and Bornean females lasts 6 to 8 months.
table below summarizes our experiences with breeding of temple pit
vipers in captivity as well as some of our observations in the wild.
snakes and gravid females observed in the wild and in captivity,
including data on mating and litter size (in parenthesis)
- April, May (Penang)
gravid females - December to
March, also July
- May to June (Germany)
- April (Phuket)
(6-12) - March, April (Germany)
newborn (7) from 3-yr-old female end of January, mating in July of previous yr (Thailand)
gravid females - February-April
N-Sum: birth - mid April (18)
(7-20) - July to September (Germany)
newborn (8-16) - February to April (North Sumatra)
(7-10) - January (Germany)
||gravid females - February
- November (Germany)
- September (Luzon)
(2-5) - May to August, also January (Germany)
© 2003-2008 Thomas Jaekel & Ewald Toenjes
one assumes a 6-months gestation period, and compares the data in
the table with the corresponding climate charts above, it is probable
that mating in Thai and western Malaysian populations occurs around
October to November, during the rainy season. However, I also observed
gravid females on Penang island in July, meaning that mating in the
wild may take place also during other periods of the year. Northern
Philippine populations (Luzon) may mate during the dry season, provided
that the Manila chart is some kind of representative for other locations
in the northern Philippines.
young in captivity
females usually give birth during the night. The tiny newborn vipers
(around 20 cm) are quite agile and can climb vertically sticking to
the wall of the container after spraying with water. Young Wagleris
look very similar, regardless of their geographic origin. We have
developed some kind of sense to distinguish them, however, coloration
can be misleading. The juveniles displayed in the 'Biology' section
are typical for populations in Thailand and western Malaysia. Sumatran
newborn tend to show a stronger uniform green coloration, with a green
or yellow venter and strongly contrasting red-white marks on the back.
However, blue forms also exist. Usually, all of them are quite docile and do not readily accept baby-mice.
Female Sumatran Wagleri and her offspring.
Newborn T. wagleri from northern Sumatra. Out of 18 young, the 9 seen in this picture were born dead. In this case, it was probably due to rough handling (physical impact or stress) of the gravid mother. Another reason for potential complications before and during birth are infectious diseases: infections with Pseudomonas aeruginosa, for example, can be detrimental to the young.
Note that here males as well as females exhibit either a basic green or blue tone. This is quite predictive for the coloration of the adults later on. As mentioned above, there also exist Sumatran populations which are more uniformly green.
newborns have a fairly different temper. They are similar in size
like young of the other populations, although the parents are relatively
smaller (females, 60-90 g, 40-50 cm; males around 30 g, 40-45 cm)
than their Sumatran or Malaysian counterparts. They are quite agressive
and immediately accept newborn mice, dead or alive. This holds true
also for young of some populations from Borneo.
Wagler's vipers bred and born in captivity:
panel: Newborn female and male of Kalimantan form, Borneo (F1)
Two newborn males from Sumatra (F2), the left one has a malformed head.
Newborn female from northern Philippines (F1) in the terrarium of Ewald Toenjes. This is probably the first successful breeding of that kind in Germany.
vipers that do not accept newborn mice either have to be force-fed (see page 'Wagler's viper in captivity') or offered small lizards,
especially geckos. As geckos are usually not readily available, forced
or assisted feeding is the only choice. Even if lizards were available,
one has to consider that once the snakes get used to this prey item,
it might be difficult to change the diet later. So, better start with
mice right from the beginning. A leg or tail of a newborn mouse given
every 2 weeks is sufficient at the beginning. At a later state, attempts
should be made in stimulating the young vipers to take a complete newborn mouse.
This can be best achieved by heating a food item under a lamp (about
40° C) and moving it in front of the young. Touching its
back or tail also provokes bites, and finally takes.
juveniles accept newborn mice or parts of it, things are going to
be easy. Then, it is very important not to overfeed the young. This
means practically, a next feeding session is scheduled only, after
the animal has completely defecated (urid acid and fecal pellet).
Father and son: 1.5 year-old Kalimantan male (F1), below, and his father. We think he got his father's nose and chin !