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

Please see Part I of this article for background information on substrate and food related intestinal impactions, including some interesting stories from the field.

Substrates for Aquatic Animals
Surinam toads, mata-mata turtles, axolotls, mudpuppies and other wide-mouthed aquatic animals that utilize suction (the flow of water into the gaping mouth) to capture prey quite frequently swallow gravel in the course of feeding.

If you do not care for the look of a bare-bottomed aquarium, our life-like Cypress Mat is well worth considering as a bottom-covering. It cannot be swallowed, is easily rinsed, and many animals will nestle down into it as a shelter. I suggest leaving a bit of the aquarium’s bottom uncovered by the mat until you can determine where your animals prefer to remain.

Sinking driftwood and Mopani wood are also safe to use, and will go a long way in improving your aquarium’s appearance.

Shelters for Burrowing and Aquatic Animals
Artificial and wood-based caves and hideaways are often accepted as substitute shelters by burrowing animals; plastic models are fine for use in aquariums as well. If so inclined, you might also enjoy using novelty decorations and shelters for pets prone to ingesting gravel and sand.

Cork bark pieces and rolls make fine shelters for terrestrial herps, and may be wedged against the aquarium’s sides to form an underwater retreat as well.

Hagen Silk Plants  are an excellent option for African bullfrogs, marine toads and other large animals that prefer to back into vegetation or moss as opposed to using a cave. These plants are equipped with suction cups, and when arranged to hang down to the terrarium’s floor they provide a naturalistic retreat. They can be used in a similar fashion under water – Surinam toads in particular prefer this arrangement to a cave.

Tong-Feeding and Separate Feeding Enclosures
Training your pets to feed from tongs will also go a long way in avoiding substrate-swallowing problems. Use plastic tongs for animals with a vigorous feeding response and reserve metal tongs for those that feed gingerly or accept large food items.

Well-acclimated reptiles and amphibians often feed eagerly even after being transported to a separate feeding container. Transferring such animals to a bare-bottomed plastic terrarium or similar enclosure is a useful feeding option.

Further Reading
The Manuel of Exotic Pet Practice’s entry on intestinal impactions is posted here.

Please see Part I of this article for further information.Last time we took a look at the amazing diversity of tiny invertebrates that inhabit leaf litter, and their importance as food for small terrarium animals such as poison frogs, dwarf leaf chameleons, and young frogs, lizards, mantids and scorpions.

Collecting Leaf Litter Invertebrates
As mentioned in Part I of this article, the springtails, ants, mites, millipedes and other creatures inhabiting a single acre of fallen leaves can add up to an astonishing 3 tons in weight! So how do we harvest all of this free food?

A technique borrowed from professional entomologists (insect scientists) works quite well. Simply place a handful of leaf litter into a funnel, suspend the funnel over a jar and position a 100 watt bulb about 6 inches above the leaves. The heat will drive the resident invertebrates down the funnel and into the jar. A damp paper towel placed at the bottom of the collecting jar will assure that the more delicate animals survive.

Using Wild-Caught Invertebrates
Remove potentially dangerous animals such as biting ants and centipedes, and dispense the rest to your poison frogs, baby anoles and other such creatures. Their reactions to this novel food will convince you of its worth – most terrarium animals become noticeably excited and feed ravenously each time they are presented with novel prey species.

Use Petri dishes if you prefer to keep your pets’ meals confined to one area. Springtails, sowbugs and others may colonize the terrarium substrate if allowed to disperse, which is also useful in some cases. You can also place small piles of leaves directly into the terrarium (after checking for dangerous species) – its great fun to watch frogs and other creatures search through them for tasty snacks.

Zoo Experiences
Others far more inventive than I came up with this technique, but I have long championed it in my articles and books…usually without much luck! Even among my zoo co-workers, my pleas fell on deaf (if amused!) ears.

So, upon touring several zoos in Japan recently I was thrilled to learn that several keepers, after reading about the topic in a book that I wrote some years back (Newts and Salamanders, which for some reason is popular in Japan), tried it out. Their results were so positive that the technique is now a regular part of the husbandry regime in several collections!

Trapping Tiny, Flying Insects
The Zoo Med Bug Napper, a very effective insect trap that I rely upon throughout the warmer months, will attract tiny gnats, moths, beetles and flies along with larger insects. These too make fine foods for your smaller pets.

Further Reading…Meadow Plankton
“Meadow plankton” is a term given to the myriads of insects and other invertebrates that can be gathered by sweeping a net through tall grass in fields and in overgrown areas along roads, farm edges, parks, etc. These creatures can also be fed to smaller reptiles, amphibians and invertebrates. Please look for my future article on this topic.

Until then, a partial species list of insects that might be encountered in a typical temperate zone meadow, along with other information, is available on the website of the Invertebrate Conservation Trust.

Please see Part I of this article for information on our prepared box turtle diets.

Natural Food Animals
Live mealworms, waxworms or earthworms mixed into canned or pelleted food should encourage your turtle to take a bite. Earthworms are a box turtle favorite and a highly nutritious food in their own right…they can comprise 25% or so of the diet. An occasional pre-killed pink mouse is usually a great hit with box turtles, but is not a necessity.

Canned Snails and Insects
Canned insects and invertebrates offer an excellent means of increasing dietary variety while adding to the attractiveness of commercial turtle foods. Box turtles avidly consume snails and slugs in the wild…canned snails are nearly always well-accepted by pets. Canned silkworms, grasshoppers, crickets and mealworms should also be offered.

Fruits and Vegetables
Commercial diets should also be supplemented with a wide variety of fruits and vegetables, including apples, pears, berries of all kinds (berries are a favorite, but should form only a part of your pet’s salad), cucumbers, carrots, mushrooms and others. Sweet potatoes are usually a favorite. Avoid bananas, as turtles often eat these to the exclusion of all else, and they are not a natural food item.

Vitamins, Minerals and UVB Light
A vitamin/mineral supplement should be provided once weekly for adults, three times weekly for youngsters.

Box turtles should always be provided with a source of UVB radiation (via a fluorescent or mercury vapor bulb ) so that they can properly utilize the calcium that is contained in their diets. Please see my article on Reptisun UVB lamps  for further information.

Wood Turtles

Wood turtles can be fed as described above; although some individuals can be picky feeders, they tend to accept a wider range of foods than do most box turtles.

Further Reading
Please see my article Providing a Balanced Diet to Reptile and Amphibian Pets for further information on reptile and amphibian nutrition.

You can read about ongoing field research projects involving box and wood turtles in the Northeastern USA at http://www.turtleconservationproject.org/projects.html.

Everyone associates the poison or “dart” frogs (Family Dendrobatidae) with skin toxins, but it is to the slow, seemingly benign newts and salamanders that we should really pay heed. In many cases their toxins are far more virulent and, unlike those of the poison frogs, they are produced internally and are not dependent upon diet for their existence (in other words, the toxins do not decline after a time in captivity, as is the case for poison frogs!).

One of Earth’s Most Toxic Creatures
Over 200 compounds, some of which are medically significant, have been isolated from newt and salamander skins. Western North America’s rough-skinned newt (Taricha granulosa) possesses what may very well be the salamander world’s most powerful secretions…a single adult packs enough to kill 25,000 mice. More than one person (usually male, drunk and involved in some sort of “initiation” or dare), has suffered fatal consequences after swallowing a rough-skinned newt.

Skin secretions entering tiny cuts have rendered researcher’s limbs numb for hours, and a scientist who rubbed his eyes after touching a “woodland salamander” (I cannot recall the species, but belonging to the red-backed/slimy salamander group) wandered about blind for nearly 3 days before being rescued.

Toxins vs. Eel
Although the California newt’s (Taricha torosa) toxins pale in comparison to those of its rough-skinned cousin, they are not to be trifled with. I kept a California newt with an American eel for 17 years. The eel, a voracious predator that would as soon latch onto my hand as anything else, never once molested its seemingly defenseless tank-mate.

Next time I’ll relate an encounter I generated as a foolish 13 year old working in a pet store, which clearly illustrates the toxicity of even the most familiar of North American newts.

Further Reading
You can read more about the natural history and toxicity of the rough-skinned newt at http://www.amphibiaweb.org/cgi/amphib_query?where-genus=Taricha&where-species=granulosa&account=amphibiaweb

California Newt Image referenced from Wikipedia Commons and originally posted by Justin Johnsen

A Control Program Backfires
Please see Part I of this article for background information. With introduced green iguanas (Iguana iguana) driving endangered burrowing owls from their nests and raccoons (Procyon lotor) devouring sea turtle eggs, the Florida Department of Environmental Protection initiated control measures. At a preserve in Dania Beach, an intensive trapping and collection campaign greatly reduced the numbers of both species, but an unexpected consequence of these efforts soon became apparent.Within a year of the raccoon numbers being brought under control, iguana populations skyrocketed. In one area of the park, researchers counted 626 iguanas per square kilometer (0.4 square miles)…an unprecedented density for any lizard species!

It seemed that raccoon predation had been a very effective control on iguana numbers. Although hawks, gray foxes, night herons, alligators and other animals prey upon iguanas, only raccoons take eggs, hatchlings and sub-adults in significant numbers.

Iguanas…Here to Stay?
Young iguanas are now especially common at the site, pointing towards an even greater population increase in the future. Hand-collection, although possible, is a daunting task, so biologists are looking into alternate control measures. Meanwhile, spurred by ample food and little competition, lizards as young as 2 years of age are laying eggs.

In Belize, black rats effectively control one green iguana population by taking nearly every egg laid. However, Florida’s parks already have enough problems without black rats…in fact, their notorious cousin, the Norway rat, is already a resident of many!

Further Reading
It was my good fortune to work with green iguanas in a natural, if somewhat unusual (i.e. treeless) habitat. Please see my article, The Green Iguana on the Venezuelan Llanos  for the story.

To learn more about the challenges and rewards of keeping these impressive lizards, please check out our care guide, Green Iguanas.