Breeding and care in captivity of the Santa Cruz Garter Snake, Thamnophis atratus atratus (Kennicott, 1860).
Steven Bol (Author…)
Raising the young
After birth the young are separated from their parents and placed in smaller terrariums (52 x 35 x 30 cm or 32 x 27 x 30 cm) in groups of ideally not more then 10 snakes. Usually the young shed their skins directly after birth just like all other garter snakes, unlike the European Natricinae like the Viperine watersnake (Natrix maura) where this event takes place 7 – 10 days after birth.
In case the baby garter snakes have difficulties shedding their skins it is advised to place the snakes in a very moist container for a few hours. Then either try carefully to help the snakes with shedding their skin or place the snakes in their terrarium with sufficient rough surfaces likes rocks or pieces of wood so they can do it themselves. But usually this is not necessary and a sign of a lower fitness.
As far as temperature and decoration are concerned the terrarium for the young is identical to the one for the parents (see chapter “the terrarium”).
Normally I offer the babies food for the 1st time after a few days to a week. The diet consists of fish, just like the parents. Ideally the size of the fish is chosen so that the widest part of the fish is slightly wider then the head of the baby snakes (so they can eat it just barely at once). Other wise I cut the fish in small pieces (including scales, intestine and bones). They are offered more food then they can eat within 12 hours, and normally the following day or morning the left over’s are removed.
Food is offered every 5 – 7 days.
In the last years raising the young has been without problems (see chapter “problems and diseases”).
Problems and diseases.
Over the past 7 years of keeping Thamnophis atratus I have not had many problems.
Some things are worth mentioning though.
The first 2 years I kept the snakes in a large terrarium in which I tried to simulate the natural habitat. The snakes did not thrive very well, ate insufficient amounts of food and where rarely visible. Looking backwards I think that the terrarium was too cold in the spring and fall: a combination of a large size (150 x 50 x 90 cm lxwxh), abundant ventilation and limited strength of the light bulbs. The poor circumstances may have increased the number of Flagellates, so I treated the snakes with FLAGYL (200 mg/ kg body mass, given oral twice with a ten day interval). After the snakes have moved too smaller and warmer terrariums limited appetite has not been an issue anymore and none of my snakes showed signs of mall nourishment.
The fact that my snake room is strongly influenced by outdoor temperatures makes simulating the temperatures as they are in spring in their natural habitat fairly easy: With strong light bulbs (since room temperatures are low early spring) the daytime temperatures rises sufficiently whereas the night temperatures drop down significantly. After the hibernation the behaviour of the snakes is observed closely: are they sunning themselves regularly, have they started mating and are they feeding well. If this was the case I usually did not measure the temperatures anymore in the past . And this created a potential problem!
The strong (60-75 watts) light bulbs, needed to heat up the terrarium early spring, were usually not replaced until they broke down or until I really noticed that temperatures got too high. I never measured the terrarium temperatures later in spring and summer so I do not have precise data. But over the years it slowly started to realise that I had a problem with temperatures rising too much inside the terrarium in the summer. Every now and then I did switch off the lights when high outside temperatures were expected, but there were several warm days were I forgot to do this. Or the temperatures rose unexpectedly, or I had not observed the weather forecast.
As I explained before the snakes moved to a smaller terrarium in 2002 after being in the large habitat terrarium for 2 years.
Table 1 shows that the breeding results of 2002, 2003 and 2004 were quit poor: 2002; 7 young born from 2 females, of which 5 were born dead (71 %), 2003; 22 young from 3 females of which 4 were born dead (18%) and in 2004; 44 young from 4 females of which 32 (72 %) were born dead. The results of 2004 were so obvious and disappointing that I realised something was wrong. I measured the temperatures at the coolest spot in the terrarium right after birth which was as high as 35 – 37 °C on some warmer days (room temperatures 31 °C).
A very stupid mistake! Over the years I had emphasised on higher temperatures in early spring to get the snakes started but forgot to slow down in late spring/early summer.
The “pig-tails”, increased melanism and high number of still born young was also observed in Thamnophis sirtalis tetrataenia which was housed together with Thamnophis atratus.
Based on these facts I conclude that too high temperatures in the (in this case) last part of the pregnancy can lead to a high percentage of dead born young, smaller young, increased melanism and the occurrence of a “pig tail”.
As far as I know this has not been described previously in literature.
I do realise that other factors can play a result since I have not done real trials to confirm my suspicions under controlled circumstances.
In order to try to prevent this from happening I placed a thermostat in my snake room early spring 2005 which automatically shuts off all light bulbs once the temperature reaches a certain maximum temperature. As a threshold I usually use 24 – 26 °C (depending on time of the year. In the summer I use bulbs with lower amount of Watts which lowers the difference between temperature inside and outside the terrarium)
Looking at the breeding results (table 1) the effects of a better temperature management seem obvious: in 2005; 56 young from 4 females of which 2 were born dead (3,5 %) and no “wax eggs”; in 2006; 57 young of which 3 were born dead (5,2 %) and no “wax-eggs”. The average length was 22,7 cm and not a single baby with a “pig tail”.
Breeding and care in captivity of the Santa Cruz Gartersnake, Thamnophis atratus atratus (Kennicott, 1860).
In this article an unknown gartersnake is introduced: Thamnophis atratus atratus.
After a short description of the animals and their natural habitat the author discusses the husbandry of this species.
The requirements of the terrarium are described extensively.
The author considers hibernation essential for keeping this species true to nature and for systematically breeding these animals.
Also newly-born animals hibernate at an age of five months.
The active season following the hibernation and the reproduction is described and some data accumulated in the last six years are analyzed.
The data on growth of several individuals are given, as is the variation throughout the years.
Remarks are made concerning age and length when reaching sexual maturity.
Finally some notes are given to problems and diseases with this species.
An, until now in the literature never described, effect of keeping the animals too warm during pregnancy (percentage still-born, length of the juveniles, “pig-tails” and colour) is described.