Breeding and Care of Blue-Tongues and Shingleback skinks (Tiliqua)

Blue-tongues and Shingleback skinks (Tiliqua)

Overview

If you live in Australia then chances are you have come across this iconic lizard at some point. This group of lizards can be found in much of the country and have even managed to survive in urban areas where the site of a blue tongue in your garden can be a common occurrence.

Many young person has had their fascination of reptiles triggered by these large robust and harmless lizards. Many reptile enthusiasts would go on to tell their tales later in life about the blue tongue they caught at the local creek or found in their grandparents veggie patch that “started it all”.

The blue tongue makes a fantastic pet for anyone looking to get their first reptile, they are large enough to be picked up, carried around and patted with little or even no stress to the animal and hardy enough to tolerate all the early teething mistakes that can often come with owning your first reptile. Captive specimens have very calm demeanors and are great for even the youngest of the family.

Captive management

Outdoors - If you live in the area your Blue Tongue is from or a similar environment then outdoor pits could be a good choice for housing. It’s important to note that Shinglebacks should not be kept in outdoor enclosures outside their natural range as they are very prone to respiratory infection when kept in moderate humidity areas like the eastern coastal strip and eastern Victoria

Outdoor pits don’t need to be overly high to keep your blue tongues in and a timber or tin wall approximately .600mm in height with a smooth surface on the inside to stop climbing and snout rubbing would suffice. You could make the walls lower if you put a “lip” around the edge or a secure lid.

Substrate in outdoor enclosures should drain well and not stay wet for days after rain. Sand and mulches such as eucy or cypress would work well and can be easily replaced when needed. Outdoor enclosures need to have sufficient hiding spots for blue tongues, this can include plastic tubs buried in the ground with a hole cut in it, bricks, drain pipes, small shrubs etc. this helps them to escape the elements when they choose as well as reducing the chance or predation from cats or dogs if you don’t have a wire top on the outdoor enclosure.

When housing multiple animals remember that Eastern Blue Tongues and Blotched Blue-tongues are often the most territorial, any new individuals introduced to an existing group could suffer and may need to be monitored to ensure they are not being picked on. Its best to house them as a single male with one or more females depending on enclosure size. Males will almost certainly fight if housed together.

Hides will need to be dry, non-drafty spaces that remain within a suitable temperature range even through the coldest of winter nights. We want to provide a place that will remain a few degrees warmer than the cold air outside the shelter. A solid walled box made from wood or plastic that is buried into the substrate in a sunny position in the enclosure with an entry pipe attached for access would work great.

The box will need a decent amount of dry bedding to burrow into and hay or dry grass would work well. An ideal box would have an insulated lid that could be lifted to enable the keeper to check on the lizards periodically with minimal disturbance.

Indoors – Blue tongues are large lizards and require large enclosure with plenty of room for them to move about freely. Many keepers like to house their animals in pairs or small groups throughout the year, if this is the case a pair of adult blue-tongues or Shinglebacks would need an enclosure size of 1200mm x 600mm x 400mm, height isn’t overly important but if you can give a bigger floor area then they will only benefit from this.

Cage furnishings can consist of rocks and logs and will need to be secure to ensure animals cant dislodge heavy items and crush themselves. It can be beneficial to arrange them in a way to allow cage mates to get out of direct sight of each other when in different areas of the enclosure. This enables any stressed animals to escape from the direct notice of more dominant animals for a short time if need be.

Enclosure substrates can consist of either newspaper, paper cat litter, red or beach sand, soil, mulch, hay, aspen bedding or even gum leaves from your garden. When selecting your substrate consider that blue-tongues and Shinglebacks love to push themselves into and through substrates, so a loose substrate would be ideal.

Heating your blue tongue can be done with a radiant heat source such as a ceramic heat emitter or a mercury vapour bulb, I would recommend the latter due to the UV output even though blue tongues have been proven to live long healthy lives without UV its always better to provide it if you can. Position this over a large rock or tile to maximize the warmth the lizard can gain from the area and ensure temperatures are reaching 30 - 35°C

Diet

Blue-tongues and Shinglebacks are omnivores and are relatively easy to feed, this means they will eat both animal and plant foods. Shinglebacks are said to eat around 80% vegetation based foods and 20% animal food types. Blue-tongues can be fed a diet with slightly more animal based food that would equate about 50% of their diet. Eastern and Blotched Blue-tongues and Shinglebacks can be fed on a varied mix of foods that include fruits such as banana, kiwi fruit, tomatoes, chopped apple or pears and strawberries. Vegetables such as shredded or diced cabbage, broccoli, lettuce, bok choy, finely diced carrot and mushrooms. These lizards are also fond of flowers like dandelions, milk thistles, rose petals and various daisy type flowers. Invertebrates such as cock roaches, mealworms and crickets and SNAILS are eagerly accepted and are the preferred items to provide the invertebrate part of the diet. Dog and cat foods can also be offered occasionally or you can try our own home made Omnivore Gel Mix a complete diet for your lizard, just add boiling Water!

Adults can be fed three days a week and a portion about the size of their heads should suffice. Juveniles should be fed every day for the first two or three months of life until they are well established, from there they can be fed on the same as the adults. Depending on what is fed, an occasional dusting with a vitamin and calcium powder is recommended about once a week.

A Shallow water dish is important for the eastern and alpine blotched blue tongues and can be kept in the enclosure permanently and the water changed regularly. Shinglebacks and centralian blue tongues have evolved to not require water as often and the permanent presence of a water bowl could bring on respiratory infection in these animals. Offering these animals a water bowl once a week should be more than sufficient for these animals.

Breeding

Sex determination of adult bluetongues is not always easy, one method is to grasp your adult blue tongue and attempt to manually evert the hemipenes of males by rolling your thumb up the tail towards the cloaca in the same way you might a snake, but this technique is best done by someone with experience. A lot of force is needed to achieve this and it takes considerable skill to successfully apply this procedure. If this done incorrectly a male may be misidentified as a female and due to the force required this could also cause the animal harm, therefore this is probably not the most recommended method.

There is a less intrusive and safer method but not quite as accurate, this is done with visual ques. Males often have bigger and chunkier heads than females, and females tend to have more robust bodies than males of the same SVL. Males will have small hemipenal bulges on the underside of the tail when compared to females. Males seem to have longer tails than females, possibly due to housing the hemipenes.

All blue-tongues are seasonal breeders, generally mating in the spring months and delivering their live babies in the summer months. Animals housed outdoors will be triggered by the natural seasons, short day length and cool temperatures during the winter, followed by lengthening the days and warming temperatures in spring. When kept indoors these events can be started by lowering the hot spot temperature to 25°C and shortening the number of hours the heat source is on, this should be done over a period of about six weeks leading into the cooler months. Ensure there is no feeding leading up to and during this time. Once the weather starts to warm up the hot spot can be slowly increased over a six week period again until back at 35°C. If animals are kept separately and are actively moving around the enclosures, males can be introduced to the females enclosure.

Shingle Backs are known to form monogamous partnerships where the same male seeks out the same female each breeding season over the life span of the lizards. In captivity, it is preferable to maintain any successful pairs together each breeding season, as trying to get an established male to mate with a new partner could take as long as several years before successful mating occurs.

Young

Baby Blue tongues are born live, the young emerge in membranous sacs that contain residual yolk material and soon after leaving the mother they will eat the membrane. The baby lizards are precocial (independent) from day one and do not usually stay with their mother or their siblings.

Young lizards should be removed from the mothers enclosure and set up with heating and lighting as for adults and fed similar diet with the obvious difference the pieces being cut suit their smaller size.

Centralian Blue-tongues produce 3 - 8 young usually born in Febuary, Blotched Blue-tongues have 2-12 young, born in late summer to early autumn from February to March, Western Blue-tongues have 3-10 young, Eastern and Northern Blue-tongues produce between 5-24 and are born in mid to late summer. Shinglebacks have 1-4 (usually two) young born in late summer February to March.