In their natural environment Blue-tongued Skinks are opportunistic feeders. This is an adaptation that suits their omnivorous tastes perfectly, making it possible for them to eat almost anything that comes their way, or anything they happen to stumble onto. In the wild they are known to eat arthropods, snails, baby rodents, and other small animals. Blue-tongues also take advantage of the native fruits, berries, flowers, and grasses, readily consuming them when available. By not being specialized hunters with prey specific needs, Blue-tongued Skinks have gained an edge over their reptilian competition, which explains their strong presence in so many different Australian habitats, including urban backyards and gardens.
Skink Mix
In captivity, I do my best to duplicate the blue-tongue's natural diet. If there were only one word that I could give as advice to a new blue-tongue owner, in regard to proper Blue-tongue nutrition, it would have to be variety. For the Blue-tongued Skink, variety is not only the spice of life; it is a way of life. My skinks relish my cooking, and I have devised a skink mix that makes up for the majority of their diet. This mix is easy to freeze and store in individual zip lock bags. I try to maintain a ratio of 50-60% animal matter to 40-50% Plant matter in their mix. I always try to include new ingredients, when making the mix, so that it is never exactly the same. I have listed some of the items that I frequently use in my mix below.
Animal Matter
Canned premium cat or dog food (I usually use chicken flavored cat food), moistened monkey chow, ground turkey, dry premium dog or cat food (moistened), hard boiled eggs, lean cuts of meat, boiled chicken, imitation crab meat (sparingly), caned reptile diets, moistened turtle pellets, and moistened koi pellets (sparingly)
Plant Matter
Chopped mustard, collard, beet, and turnip greens, dandelion greens and flowers, hibiscus flowers (take care that no pesticides or herbicides are present), chopped kale (sparingly), fresh, canned, and thawed frozen fruits, canned or frozen mixed vegetables (peas, carrots, corn, and green beans), grated squash, carrots, apples, and potatoes, moistened iguana diet, and cooked pasta
Supplemental Food Items
Most insects are taken readily by Blue-tongued skinks. If you are feeding insects, that you have collected, to your skink, it is important to make sure that there is no chance of them being contaminated with pesticides. You can purchase crickets at most pet stores, and they are available in bulk through a large number of mail order companies that advertise in reptile related magazines. Also available are mealworms (Tenebrio molitor), superworms (Zophobas atrauts), waxworms, and sometimes earthworms. Snails are relished with delight by most blue-tongues, but again, you should be certain that no pesticides are present. Rat-pups are great for skinks that are a bit thin and need to put on some weight, and young adult mice make an excellent weekly supplement for gravid females. I also like to offer my skinks an occasional fruit meal consisting of ripe strawberries, peaches, mangos, or canned fruit cocktail.
Vitamin and Mineral Supplementation
A quality calcium supplement with vitamin D3 is an important factor in maintaining most lizards, including Blue-tongued Skinks. Make sure it is phosphorous free, and do not over supplement. Sprinkle a small amount on the food every other feeding for babies and gravid females, and every third feeding for all other adults. If given a varied diet, blue-tongues will not need any other vitamin or mineral supplements.
Lights and Heat
There are many opinions in regards to lizards and full-spectrum lighting. While it has proven to play an important role in the development and vitamin D3 synthesis of many Iguanid and Agamid species, I am not totally convinced that it is absolutely necessary for the proper growth and development of Blue-tongued Skinks. There are many reports of blue-tongues being raised without any exposure to full-spectrum lighting. However, in the wild, blue-tongues do bask in the sun. Weather this is for UV light benefits, or simply just to raise their body temp, is still in question. I personally believe it to be primarily for the purposes of thermoregulation, and the synthesis of vitamin D3, and I cannot discount the possibility of additional benefits. I would much rather play it safe than sorry, and I still believe that the potential psychological and physiological benefits of full-spectrum lighting make it well worth the effort. A photo-period of 12 hours on and 12 hours off can be established and controlled through the use of a household appliance timer. I maintain this 12-hour photo-period for the entire year, with the exception of when I am cycling my skinks for breeding. A thermogradiant should be established in the cage by providing a basking site of 90-95 degrees at one end of the enclosure while maintaining temperatures of 80-85 degrees at the cool end. This can be accomplished by using an under tank heating pad or spotlight of appropriate wattage, and it will allow the skink to control its body temperature my means of thermoregulation. Night-time temperatures of 70-75 degrees are acceptable.