Captive
breeding and a novel egg incubation technique of the Childrens Python (Liasis
childreni)
By Brian Barnett, 16 Suspension
Street, Ardeer, Victoria, 3022, Australia
(Originally
Published with 4 b/w illustrations in Herpetofauna 11 (2), 28 February
1980, pp. 15-18)
My Childrens Pythons are not housed
individually but kept together throughout the year in one community cage.
As L. childreni have a good record of breeding under these
conditions I have never worried about the separation of sexes prior to
planned matings.
On the 15th June 1979 two of the pythons
were observed mating. They were not disturbed and were connected for a
minimum of 50 minutes. This female failed to produce eggs. No other matings
were observed (the cage is equipped with hide-boxes). Regular checks were
made of the females and in mid September one was found to be gravid.
On the 10th October 1979 she deposited
4 eggs. Three eggs measured 5cm x 2.2cm and the fourth 5.5cm x 2.1cm.
The four eggs were placed in a plastic
container and in the incubator. Vermiculite was used as the hatching median
and it covered the eggs by approx. 1cm. The vermiculite was then given
a liberal spray of water. During the period of incubation, the eggs were
kept between 29.5 and 32.0 degrees Celsius. The eggs were inspected each
day and the vermiculite given a fine spray of water when thought necessary.
In the early stages of incubation this was almost daily but became less
frequent later ( the container was sealed).
I had my E.D.A. (Estimated date of
arrival) worked out as the 1st December and on inspection of the eggs on
the 9th November, I was surprised to see one of the eggs split open almost
from end to end. This was only 31 days into incubation and just over half
of the estimated time for incubation. On close inspection it was found
that the egg had burst open and that the embryo was not sufficiently developed
and certainly not ready to emerge. The egg had burst from excessive internal
pressure due to the absorption of too much moisture . The egg was removed
from the medium and given a closer inspection. Watching the 'little pink
snake' laying there in his now wrecked egg made the mind search for a solution
rather than throw it out and put it down to experience. The thought of
a humidicrib came to my mind and anything was worth a try. The snake was
still in the shell, which was wide open. If I applied the right conditions
maybe it could work?
The humidicrib was set up from a clear
top plastic bread container without any ventilation. 2cm of vermiculite
was placed in the container and given a heavy spray of water, more than
would normally be given to incubating eggs. The clear plastic top was used
in order to be able to observe the egg without opening the container. Suspension
of the egg was considered necessary and the next step was to cut the bottom
out of a 500gm margarine container from which the egg could be suspended.
Removing the bottom of the container would allow water vapour to circulate
more freely and evenly once it was placed on the vermiculite. The egg was
then suspended by threading cotton through the split edges in four places
so as to give a large observation window. The four threads ware then stitched
and tied to the top edge of the container (Fig. I). The egg was suspended
so that it did not touch the vermiculite and was approximately 1 cm above
it. While the egg was being stitched and tied, some of the clear albumen
spilled over the side and was lost.
No extra moisture was given to the
vermiculite during this humidicrib experiment and the only time that the
lid of the container was removed was when photographs were being taken.
Clear observations could be made at any time. To obtain a better view for
both observation and photography, the embyo was probed and moved with a
sterilized seeker.
Finally on the 1st December, the young
male crawled over the side of his egg and came into the world several hours
in front of the others in the good eggs. He came out after spending 23
days in a very open environment and was in excellent condition.
When one is a keeper, breeding is the
ultimate aim, and when unforeseen situations such as this occur new add
interesting challenges present themselves. It is particularly rewarding
to succeed when a failure is fully expected. Two of the young were born
on the 1st December and the other two on the 2nd December. (53 days and
54 days).