That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

The process of hibernation (or brumation) in reptiles and amphibians seems subject to a great many factors.  For example, I have noticed that spotted and Eastern box turtles, and other temperate North American species, vary greatly in this regard.  In captivity, wild-caught individuals usually slow down (activity and feeding) during the winter, even if kept warm and given a photoperiod of 12 hours.  Captive-born animals of the same species most often continue to feed throughout the winter.

Green frogs, garter snakes, musk turtles and others, however, usually stay active if kept warm in winter, even if wild-caught.

A recent email from a colleague brought up the subject of bearded dragons.  His animal becomes lethargic and ceases feeding in October, despite a long photoperiod, and high ambient and basking temperatures.  Most bearded dragons in the US pet trade are several generations removed from the wild, yet the tendency to hibernate persists in some.  Many bearded dragons, however, remain active all year.   I am wondering if what we are seeing is related to the natural range of our pets’ ancestors… perhaps those from certain areas hibernate in the wild and retain this pattern in captivity?

A Request for Help

Internal (circadian) rhythms exert their influence on most animals, and an understanding of their workings is vital from both a pet-keeping and conservation point of view.  I would greatly appreciate being informed of any seasonal changes in activity that you notice among your pets.

Some North American turtles are incredibly cold-tolerant, and are being studied to see if the mechanisms they use might be applied to the possible storage of human organs destined for transplant.  The abstract of an interesting The Journal of Herpetology article is posted at:

http://www.jstor.org/pss/1565569

If you’re looking for general care information on bearded dragons, check out my article: Bearded Dragon Natural History and Captive Care.

The house cricket is something of an insect oddity…at once both an adaptable, widely introduced species and a somewhat delicate captive.  Native to southwestern Asia, it fares poorly in the damp conditions favored by field crickets and other North American species.

Providing a Water Source: the advantages of gels

House crickets will not survive long in damp conditions, but they do need to drink quite a bit of water, and herein lays the main problem in keeping them.

The crickets drown rapidly in standing water, and cotton or gravel-filled bowls foul quickly.  Stagnant water, and mold on damp sponges or oranges (2 other common methods of providing water) supports bacteria that seems, for reasons not completely understood, to rapidly decimate cricket colonies.  Misting the colony, a useful technique as regard many insects, is worse, and again will result in heavy losses.

The advent of gel-based cricket water substitutes is one of the most important recent innovations in food animal maintenance.  These products save time and money by cutting down on losses.  More importantly, crickets that live longer have improved chances of consuming a nutritious diet, and thus are themselves a more valuable pet food.

I use Cricket Drink and R-Zilla Cricket Calcium Drink Supplement exclusively.  Both are fortified with calcium and other nutrients, and are readily consumed by crickets.  No other water source is necessary.  Millipedes and sow bugs will also feed upon these gel cubes, and they would be well-worth trying on scorpions and tarantulas.

A Warning: Condensation

Even when fruit and standing water is dispensed with, be sure to guard against condensation buildup.  This occurs most frequently in crowded enclosures, and will wipe out your colony in short order.  Adequate ventilation and roomy holding containers are of key importance in avoiding damp conditions.

Next time I’ll review some commercial cricket diets.  Please write in with your own tips for keeping crickets and other food animals.

You can read about the natural history of the house cricket here.

In 1969, Carl Kauffeld introduced a generation of budding herpetologists to snake-keeping with his wonderful classic Snakes: The Keeper and the Kept. In it he laid out the basic principals that had yielded him decades of success while curator of the well-known reptile collection at New York City’s Staten Island Zoo – simple, easily cleaned enclosures that provide a secure retreat and basking site. Such became, and largely remains, the standard approach to snake-keeping in the USA.

European zookeepers and hobbyists, by contrast, favor planted, naturalistic exhibits, and it was to these I gravitated. Although not nearly as easy to maintain as bare cages, for certain snakes I find complex terrariums to be a very worthwhile undertaking.

Possible Pitfalls
Cleanliness and the control of excess moisture and parasites can be major concerns…one of my first mistakes involved keeping a banded watersnake in a filtered aqua-terrarium. The animal was not able to dry off sufficiently, and developed blisters. Then Bronx Zoo curator Wayne King (imagine the curator of a major reptile department personally answering a 10 year-old’s letter today!) suggested some changes, and the snake recovered.

Candidates for Naturalistic Terrariums
In my experience, small species are the best to start with when attempting naturalistic snake terrariums. Such animals are easier on plants and decorations, and secretive snakes really do seem much more “at home” in captive habitats that offer numerous burrowing and hiding opportunities.

DeKay’s (brown) snakes do wonderfully in forest-themed tanks, and often breed readily. Other favorites of mine include smooth and keeled green, garter, ribbon, ring-necked, red-bellied and tentacled snakes.

Larger species are more easily maintained in simple set-ups, especially if space is limited, but there are still some possibilities. Watersnakes will bask on branches over-hanging a pool, just as in the wild, and corn and various ratsnakes will utilize just about every bit of cage furniture provided. Shy or high-strung arboreal species, such as green tree pythons and Cook’s tree boas, also favor well-planted terrariums perched with natural tree branches.

The Staten Island Zoo’s Reptile House Today
In an odd twist of fate, I recently had the opportunity to help plan the complete renovation of Mr. Kauffeld’s amazing building. Having grown up near to and in awe of the man and the institution, it was quite an odd feeling, to say the least. I set up naturalistic exhibits for nearly all of the snakes, but a re-creation of Mr. Kauffeld’s office holds a number of terrariums set up as he would have wanted. I sincerely hope he approves! Please visit if you have a chance…I would greatly appreciate your comments.

Please Note: some of the photos accompanying this article feature venomous snakes. These are presented as illustrations of terrarium set-ups that might be useful for animals from similar habitats, not as an inducement to keep venomous snakes at home. Venomous snakes should never, under any circumstances, be held in captivity outside of a professionally managed scientific institution.

Many zoos use complex exhibits as a means of providing behavioral stimulation to snakes. Read more at:
http://reptilebehavior.com/riverbankspaper.htm

Today I’d like to take a look at a much-maligned food insect that can, if used properly, be an important addition to your pets’ diets.

Mealworms (larvae)
A steady diet of mealworms (I refer here to the small mealworm, Tenebrio molitor, not the giant mealworm, Zophobus mario) is not recommended for any reptile or amphibian. These beetle larvae lack essential nutrients, the calcium: phosphorus ratio is not ideal and the exoskeleton is high in chitin. Mealworms also have quite strong jaws, and may injure debilitated or small reptiles and amphibians.

However, newly molted mealworms, which are white in color, are soft, have weak mouthparts and lower chitin levels. I have found them to be an excellent supplementary food for amphibians, tarantulas, scorpions and reptiles and fish.

Mealworms will shed most frequently when fed heavily and kept at 76-80 F. I house my colony in a mix of wheat bran, corn meal and powdered multi-grain baby food, with a bit of Tetramin Flake Fish Food added in, and provide banana skins for moisture.

Mealworm Pupa
Mealworm pupae are a fine food for turtles, newts, aquatic frogs and those lizards that accept non-living food items. They are low in chitin and likely have a different nutrient profile than either the larvae or adults.

Mealworm (Darkling) Beetles
Beetles, comprising the world’s largest animal family, figure prominently in the diets of most insectivorous reptiles and amphibians (based upon stomach content studies). I have long used darkling beetles (adult stage of the mealworm) as a food item, and prefer them over the larvae in most situations.

Beetles newly emerged from the pupae are softer than later-stage animals, and brown in color. To ensure a steady supply, I remove pupae as they form and place them into a bare container. In this way the beetles cannot burrow into the substrate, and are thus easier to harvest. Warm temperatures and a good diet (see above) will ensure a steady supply. Be sure to leave some beetles in the colony for breeding purposes.

You can learn more about the specifics of the mealworm’s life cycle at:
http://lawrencehallofscience.org/foss/fossweb/teachers/materials/plantanimal/tenebriobeetles.html

Image referenced from Wikipedia: http://en.wikipedia.org/wiki/Image:Mealworms_in_plastic_container_of_bran.jpg

Isopods, more commonly known as sowbugs, pillbugs or potato bugs, are a valuable but largely neglected food source for pet amphibians and reptiles. The over 10,000 described species are common in most habitats worldwide, and are therefore an important in the diets many creatures. Ranging in size from .02 to 20 inches, there is an isopod to fit every feeding need (public aquariums pay $600 or more each for giant, deep-sea forms, so don’t plan on feeding these to your monitor lizards!).

Nutritious, Interesting Scavengers
Isopods are crustaceans, and as such provide a variety of nutrients not to be found in insects. Another thing I like about using them has to do with their appetites – they will eat anything, so by feeding them a rich and varied diet you are improving their value as food items for your pets. Furthermore, native sowbugs and pillbugs will live in most terrariums and are valuable scavengers, relishing dead earthworms, crickets and feces. I always include a group in naturalistic habitats that I design for zoos and museums. Finally, they are very interesting to observe in their own right. They do contain quite a bit of chitin, so are not suitable as the sole item in a diet.

Obtaining Isopods
Temperate isopods prefer cool, moist environments, and so are most easily found in spring and fall. You can collect them below rocks and leaf litter. They will also flock to cover such as boards placed on the ground, especially if the area is kept moist and baited with coffee grounds or ripe fruit. Biological supply houses also sell starter cultures.

Keeping and Breeding Isopods
Keep your colony in a vented plastic container with 3-4 inches of R-Zilla Coconut Husk as a substrate. Plastic terrariums by Lee, Tom Aquarium, Hagen and PLA House make ideal isopod homes. Be sure to keep the bedding moist but not wet. A covering of Zoo Med Terrarium Moss will help retain moisture and offer shelter to the isopods, making collection easier.

A mix of R-Zilla Alfalfa Meal Bedding and Tetra Min Flake Fish Food is an excellent basic diet, to which can be added grass clippings, leaf litter, coffee grounds and almost any fruit or vegetable. A cool basement makes an ideal location for the colony, but average room temperatures are fine. Be sure to keep an eye on moisture levels during hot, dry periods. A breeding colony will supply huge numbers of isopods of all sizes.

My Experience
I have always kept an isopod colony for my collection, and have used them in zoos as well. They are easy to maintain, breed readily and are, I think, one of the best-kept secrets (no more!) in herptoculture. Very few insectivorous herps refuse them, and they are readily taken by many fishes and birds as well. Be sure to try a group in your naturalistic terrariums also, as they make fine scavengers and, unlike crickets, they will not attack debilitated pets.

The University of Arizona’s Center for Insect Science Education offers a wealth of information on native invertebrates in the wild and captivity. Read more about isopods at:
http://insected.arizona.edu/isoinfo.htm