Captive Reproduction of the Northern Blue Tongue Skink - By Accident!
By: Grady Calhoun
This spring my son had acquired an unrelated pair of captive-bred Northern Blue-Tongue Skinks (BTS). The male was a full grown robust animal reportedly two years in age. The female was quite obviously not full grown and reportedly less than one year old. I believed that the female was a too small to breed so I kept the animals apart planning on trying next year. They were both temporarily housed in 20 gallon long aquariums. About 1 month after we had them, my son questioned me about putting the male in with the female. Of course I stated that I didn?t but it quickly became obvious that they were, in fact, together. The reptile room is entered multiple times every day and it is impossible that they were together more than 24 hours. Actually its much more likely that they were together less than 8 hours. It is quite obvious that such a robust lizard with such disproportionately small legs can?t climb out of a 20 gallon tank- Right? WRONG! The male climbed out of his cage and rather than seeking freedom he sought, and evidently found, love.
I removed the male right away and upon examination, the female had obvious bite marks on her neck. I added a lid and designed and built more permanent facilities. I really dismissed the fact that the female may be gravid as all of the literature says that the animals should be two or even three years old before successful breeding can occur. The animals were not together, even for a second, after this event. Before I describe the blessed event I will discuss the maintenance of the animals.
The skinks were maintained in a room that was kept at approximately 82 degrees Fahrenheit during the day and allowed to cool to no less than 75 degrees Fahrenheit at night. The skinks are housed separately in melamine cages that I built. Each cage is 36 inches long by 18 inches deep and 12 inches high. Each has a basking spot that reached approximately 100 degrees during the day. I use newspaper as a substrate. Each cage has a hide box that the skinks occupy most of the time. They typically come out and bask as soon as the light comes on and to eat but beside that they are rarely seen outside of the hide box. Water is available at all times and I have seen them drink frequently.
I've read much of the literature on feeding BTS and found that the eating habits of these two animals varied slightly. The female, even before the apparent mating, relished small mice. Although she would eat low-protein canned dog food, she preferred pinkies. The male was just the opposite. In fact, he would often not eat mice when offered but would always eat the dog food. The one thing they have in common is that neither will eat vegetation without being ?tricked? into it. Since they were acquired, I have offered chopped collard greens, kale, melon, and squash. They lick it and forget it. I tried mixing the chopped vegetation with dog food and they would eat some of it. It was obvious however that they eat around the vegetation whenever possible. The food is sprinkled with multi-vitamins and calcium supplements at least weekly.
The midnight rendevous occurred in mid-May. Although I was not specifically looking for signs or behaviors of pregnancy, I noticed nothing out of the ordinary. The female remained very handleable. She typically lets out a brief hiss when first picked up but shows no signs of aggression. She continued to eat her normal food with no apparent increase in appetite. There was no apparent weight gain. The babies were born August 8 which was 11 to 13 weeks after mating.
As mentioned previously, the reptile room is visited multiple times each day so I am fairly confident I found them within 24 hours of their birth. I was in the process of changing the newspaper when I saw the first baby. I was completely surprised! There were seven live neonates and two unfertilized slugs. The literature that I have read indicates that the first thing a baby BTS does is eat the membranes with which it is born. This appears to be accurate. There were very few signs of birth except for the babies themselves and the two slugs. There were no blood stains and no birth membranes. I found this quite unusual given the typical mess that other live-bearers such as Boas leave. The female had a SVL of 10.5 inches and a total length of 17.5 inches at the time of birth.
The neonates were immediately removed and placed together in a separate aquarium. They were measured two days after they were born. They ranged in total length 4 3/4 to 5 1/8 inches long. Six of the seven babies appeared to be quite healthy and full of attitude. One of them looked wet when first discovered and was more fragile. Its rear legs were somewhat thinner than the others and his scales appeared to be somewhat malformed. Anytime the cage was approached they would puff themselves up, open their mouths, hiss, and expose their tongue, which at this point were closer to black that the bright blue of their parents. The six healthy babies were housed in a 40 gallon aquarium with incandescent lighting providing a basking spot of approximately 105 degrees Fahrenheit. The less healthy animal was placed in a small cage by himself and cared for individually.
Food was offered daily from the day they were born. The items offered included wax worms, mealworms, dog food and chopped vegetables and fruits. All of them accepted food within three days of birth. The sickly one was actually one of the first to eat. The babies appeared to prefer the insect larvae over anything offered originally. I think the movement attracted them. They gradually accepted most items offered, even a finely chopped mixture of collard greens, kale, carrots and apples.
The sickly lizard was a much less aggressive eater than the others and actually quit eating about 5 days after birth. In an attempt to save it, I provided daily feedings of strained baby food (a mixture of meat and sweet potatoes or squash and vitamin/mineral supplements) from a syringe. It readily lapped up the mixture directly from the syringe but wasn?t interested in eating any other way. After about a week of this, it finally started eating this mixture when placed on a plate in front of it. Needless to say I have become a bit attached to this one and plan on seeing it to adulthood.
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