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

Butterworms, also known as Trevo Worms, are highly nutritious caterpillars that deserve more attention from reptile, amphibian and invertebrate keepers. They have many of the advantages associated with wild-caught insects yet lack most of the risks. Their calcium content of 42.9 mg/100g (as compared to 14 and 3.2 mg/100g for crickets and mealworms) is especially-impressive. Simple to use and store, and accepted by a huge array of species, Butterworms are in many ways superior to the more commonly-used feeders. I promoted their use throughout my long career as a zookeeper, and today would like to introduce them to those readers who may be interested in adding important nutritional variety to their pets’ diets. Please also see the articles linked below for information on other “alternative” foods such as sow bugs, sap beetles, leaf litter invertebrates, earwigs and many others.

 

Natural History

Although they resemble beetle grubs, Butterworms are actually the larvae, or caterpillars, of the Chilean Trevo Moth (Chilecomandia moorei). As far as is known, they are found only in Chile, where their diet is comprised entirely of Trevo Bush (Trevoa trinervis) leaves.

 

Butterworms are collected rather than captive-reared, and are subjected to low levels of radiation before being exported from Chile. Irradiation prevents them from pupating, thereby addressing US Department of Agriculture concerns that the species could become established in the USA. This process, and the fact that they cannot be bred commercially, renders Butterworms a bit more costly than similar insects, but I believe their value as a food source merits the extra expense.

 

Nutritional Information

Being wild-caught, Butterworms likely provide nutrients absent from commercially-reared insects. They also exceed all other typical feeder insects in calcium content (please see Introduction, above), with only silkworms and phoenix worms approaching them in this regard (some find silkworms to be delicate, and phoenix worms are quite small, but both are also worth investigating).

 

The Butterworm’s protein content of 16.2% is on par with that of crickets, phoenix worms and waxworms, and below that provided by silkworms and roaches. Fat content stands at 5.21%, which is less than (considerably so, in many cases) that of all other commonly-used feeders.

 

Please Note: The nutritional needs of reptiles and amphibians vary by species and by individual age, health, and other factors. The fact that a food is “low in ash” or “high in protein” does not necessarily mean that it is a good or bad choice for your pet. Please post specific nutrition/feeding questions below.

 

Why Use Butterworms

In addition to their nutritional value, Butterworms are readily accepted by a wide variety of reptiles, amphibians, tarantulas, fishes, scorpions, birds and small mammals. They vary in coloration through shades of yellow, red and orange, and have a distinct, “fruity” scent. I’ve not seen any research on the subject, but these qualities perhaps may make them attractive to predators…in any case, Butterworms often incite interest from reluctant feeders.

 

Butterworms range from ½ inch to 1 ½ inches in size, with the average in most containers being ¾ inch. They are far plumper than waxworms, and ideally suited for both small and larger pets.

 

These colorful, chubby caterpillars are more active than waxworms and phoenix worms, yet can easily be confined to a shallow bowl or jar lid. I’ve found this to be especially useful when keeping certain treefrogs, geckos and other arboreal species that are reluctant to feed on the ground. Butterworms may also be used to provide important dietary variety to insectivorous snakes (Smooth Green Snakes, etc.), terrestrial salamanders and others that tend to accept relatively few traditional feeder species.

 

Storage

Butterworms can be kept under refrigeration at 42-45 F for at least 4, and possibly up to 6, months. I keep my refrigerator at 39 F, and have had no problems with losses at that temperature over periods of 2-4 weeks.

 

 

Further Reading

Collecting Insects for Herp Food: Traps and Tips

Earwigs as Reptile/Amphibian Food

 

Each year, a wider variety of beautiful and interesting live plants becomes available to keepers of amphibians, reptiles, scorpions, tarantulas and other terrarium animals. Responsible suppliers to the pet trade should propagate plants without relying upon pesticides, but many hobbyists are rightly concerned about the possibility of poisoning their pets. While working at the Bronx Zoo, I had access to professional horticulturists who provided me with some safety measures one can employ to assure that plants are safe for use in terrariums.

 

Pesticide Types and Uses

Pesticides may be classified by the site at which they exert their effects. Surface pesticides remain on stems and leaves, and are usually mixed with adherents in order to improve their sticking power. Adherents are chemical compounds that may also be harmful to terrarium animals. Systemic pesticides diffuse into plant tissues – these are less commonly used on house and terrarium plants than are surface-acting chemicals.

 

Many species that are marketed as house plants are much favored by animal-keepers as well. Included among these are pothos, peace lilies, Chinese evergreens, cast iron plants and snake plants. These plants have almost certainly been treated with pesticides, as they are grown in large propagation operations, and not specifically sold for use in terrariums.

 

Various ferns, mosses, bromeliads and carnivorous plants raised by those who target pet keepers as customers may or may not be pesticide free (please see below, and post a comment for further information).

 

Risks to Reptiles and Amphibians

The skins and exoskeletons of reptiles and most commonly-kept invertebrates may be relatively impervious to pesticide poisoning by casual contact. However, traces may enter the animal if tracked onto food, or, perhaps, via the pedipalps of spiders. Herbivorous species may also sample plants, including those generally considered to be distasteful.

 

Amphibians are very sensitive to chemicals of any type. Their porous skins allow substances as small as oxygen molecules to enter the body, and pesticide toxicity has been well-documented in field and lab studies (I once observed autopsies of male African Clawed Frogs that had been exposed to a common pesticide…the unfortunate fellows had developed ovaries!). While tree frogs and others that spend their time on plants are most at risk, pesticides can also diffuse through the tough skins of desert dwellers such as the Colorado River Toad.

 

Detoxifying Terrarium Plants

Plants treated with surface pesticides can be rendered safe by washing with water. Be sure to rub the leaves, stems and roots with a clean sponge, and rinse well; submerging the plant and swishing it about afterwards is also useful. I always discard the soil that arrives with plants, as pesticides that have dripped off the foliage during application will accumulate there. Vinegar, lemon oil and other products are frequently recommended as well, but I’ve not found these to be necessary.

 

There aren’t any well-established practices where systemic (absorbed) pesticides are concerned. Horticulturist co-workers at the Bronx Zoo suggested a 30 day waiting period before any suspect plant was placed into an exhibit. I did well with that protocol at the zoo, and have continued to use it in my personal collection.

 

Sources of Pesticide-Free Plants

Most terrarium plant suppliers rely (or claim to rely!) upon pesticide-free growing practices. I do not have much recent experience with any of the major growers, but can ask colleagues in the zoo and private trade for their opinions if you are unsure of your source. Please post any questions or comments below.

 

 

 

Further Reading

 

The Peace Lilies in the Terrarium

 

Wild-Caught Insects as Reptile Food: Pesticide Concerns

Turtles and tortoises often appeal even to those who would not dream of keeping – or allowing their children to keep – a snake or lizard. Their good reputation as pets is due in part to generally amiable natures and the degree of responsiveness they exhibit to people. But the needs of these interesting reptiles are not always well-understood by first-time owners, and choosing between turtles and tortoises, and among the individual species, can be a daunting task. Today we’ll look at what is involved in turtle and tortoise ownership, so that you can decide which would be best for your particular situation. As always, please post any specific care questions you may have below.

 

Please Note

The terms “turtle” and “tortoise” are used interchangeably for some species, and in different ways throughout the world. Most commonly, “turtle” refers to semi-aquatic and aquatic animals, while “tortoise” is used for those that spend their time on land.

 

The following points are general in nature. Please see the linked articles and post below for detailed information on the care of individual species.

 

Space Requirements

Turtles and tortoises need far more living space than most people realize, and many grow faster and larger than one might expect.

 

Among turtles, the commonly-kept Red-Eared Slider is a perfect example. Females (the larger sex) will very quickly reach 8-12 inches in length, at which point they will require a 75-100 gallon aquarium, a commercial turtle tub, or a wading pool. The smaller males, as well as some Musk, Mud, Map and Painted Turtles, might (depending upon the species) get by in a 20 to 55 gallon aquarium. Although hard to resist as hatchlings, Common Snapping Turtles and most Softshells grow very large, and they can be dangerous.

 

Tortoises generally need even more space than do turtles, with nearly all requiring a custom-built cage or fenced outdoor area. In addition to being very active, tortoises fare poorly unless provided with a thermal gradient. Thermal gradients, critical to good health, allow tortoises to regulate their body temperature by moving between hot and cooler areas (small cages quickly take-on the temperature of the basking site). Aquariums are ill-suited for use as tortoise homes, as they do not provide the ventilation (or space) required by most.

 

Life Support Equipment

All tortoises and turtles must have access to a source of UVB radiation, a heated living area, and a hot basking spot. For most owners, this translates into the purchase of UVB bulbs and fixtures, basking bulbs and fixtures, heat mats and ceramic heaters (tortoises) and aquarium heaters (turtles). Expenses can be trimmed somewhat if one keeps Mud and Musk Turtles, or those few other aquatic species that can get by without UVB if provided a proper diet.

 

Aquatic turtle tanks must also be equipped with powerful filters. Housing your pets in easily-dumped plastic bins eliminates the need for filtration, but this option has drawbacks in terms of visibility and aesthetics.

 

Tortoises hailing from deserts and other arid habitats are susceptible to respiratory infections in even slightly-humid environments. Therefore, a de-humidifier may be essential.

 

Diet

It is in the area of nutrition that turtles and tortoises diverge most noticeably. With few exceptions, turtles are the easier of the two groups to maintain. Zoo Med and other commercial turtle pellets, earthworms, sun-dried or fresh shrimp and several other easily-obtained foods will keep most in good health and breeding condition. Nearly all, however, should be provided with whole minnows and similar fishes on a regular basis (these are the best source of calcium and other important nutrients).

 

Healthful tortoise diets, on the other hand, can be difficult to arrange, and the needs of the various species differ greatly. Poor nutrition is the leading cause of death among captive tortoises. Please see the linked article and post any questions you may have below.

 

Workload

I receive many questions and complaints centering on the amount of work involved in keeping turtle aquarium water clean. Turtles are messy feeders, and very hard on water quality. Powerful filters help, but partial or total water changes will still be necessary (and filtration medium needs frequent replacement).

 

Land-dwelling tortoises are fairly simple to clean-up after, unless one has a large collection or concentrates on the giants of the group. For example, a pair of 80 pound African Spurred Tortoises (“Sulcatas”) under my care at a zoo brought back memories of cleaning rhino pens as a fledgling animal keeper decades ago!

 

Human Health Considerations

Salmonella bacteria are likely present in the digestive tracts of all turtles and tortoises. Handling an animal will not cause an infection, as the bacteria must be ingested. Salmonella infections are easy to avoid via the use of proper hygiene, but are a serious concern for children and elderly or immune-compromised adults. Please speak with your family doctor and see the article linked below for further information.

 

 

Further Reading

Caring for Red-Eared Sliders, Painted and Map Turtles

 

Keeping Desert, Rainforest and Grassland Tortoises

Big and bold, the Cottonmouth or Water Moccasin is one of the most frequently-encountered of the USA’s venomous snakes. Stories of its alleged ferocity abound, and many folks living within its range are convinced that it goes out of its way to attack people. I’ve had the chance to work with this impressive serpent at the Bronx and Staten Island Zoos (Note: venomous snakes should never be kept in private collections), and to observe it in the wild, and have found its actual habits to be far more interesting than the supposed ones! From scavenging road-killed pigs to turning up in areas far north of where most people “expect” it, the Cottonmouth is full of surprises. Today I’ll focus on the natural history and captive care of the Eastern Cottonmouth (Agkistrodon piscivorous picivorous), with some comments on the 2 related subspecies.

 

Description

Most Eastern Cottonmouths are olive to dark brown in color, and are patterned with irregular, dark cross-bands. However, nearly-black, pattern-less individuals are common, and hybrids (which vary in appearance) occur where its range overlaps with that of the Florida and Western Cottonmouths.

They are stoutly built, and this makes adults appear larger than their actual size. Most average 3 to 5 feet in length, but occasional “giants” turn up. The published record length is 6 feet, 2 inches…but there’s no shortage of people who will claim to have seen, or even killed, Cottonmouths twice or three times as large (note – they haven’t!).

 

Several of the larger, non-venomous water snakes of the American Southeast are often confused with the Cottonmouth, as they are superficially similar in appearance and share the same habitat. And if you’ve ever tried catching a large Brown or Florida Green Watersnake, you’ll understand why most “non-herpers” give these irascible brutes as wide a berth as they do Cottonmouths!

 

The Cottonmouth is classified in the family Viperidae, and is most closely-related to the Copperheads and various Cantils of Mexico and Central America.

 

Range

The Eastern Cottonmouth is found from southeastern Virginia to eastern Alabama and Georgia. I grew up associating Cottonmouths with Florida’s swamps and canals, and indeed it is there that the Florida Cottonmouth, (A. p. conanti) thrives in good numbers. I was surprised to learn, however, that the Western Cottonmouth(A. p. leucostoma)ranges much further north than I expected – to southern Illinois and eastern Missouri.

 

Habitat

Cottonmouths are typically found in and along slow-moving bodies of water such as swamps, marshes, canals, rice fields, ponds and weedy lakes. However, they will forage in fields, open woodlands and around farms, often far from water. Individuals in many populations hunt mainly by night, especially during the summer, but they bask in the daytime.

 

In the northern sections of their range, Cottonmouths hibernate in subterranean dens on land, often on hillsides far from water. Hibernation sites may be shared with copperheads, rattlesnakes, water snakes, ratsnakes and other species.

 

Status

Cottonmouths can be quite common in suitable habitat and in protected areas such as the Everglades, but are threatened in some regions by wetland drainage. Basking Cottonmouths are said to be used for “target practice” in some places…not much of a challenge, given their size and immobility when basking, I imagine!

 

Longevity

Zoo specimens have reached at least age 24; several under my care were in their late teens, and still full of spunk. Longevity in the wild has not been well-documented, as far as I know.

 

Reproduction

In most populations,females breed every-other-year, usually in August and September. The young, 1-16 in number, are born alive and are 7-13 inches in length. They are reddish-brown and vividly marked, and use their bright yellow tail tips to lure frogs, lizards, and other prey. Sexual maturity is reached in 3-4 years.

 

Diet

Cottonmouths take a wider range of prey than do most other snakes, and even scavenge road-kills. I was once very surprised to read a journal note (Herpetologica?) describing a large individual consuming chunks of fat from a dead pig!

 

The usual diet is extremely varied, and may include catfish, bream, eels and other fish, sirens, amphiumas and other salamanders, frogs, hatchling alligators, small turtles, lizards, snakes, ducks and other birds, and mammals such as rice rats, muskrats and voles.

 

I once housed a colony of Green Anoles with a pair of Cottonmouths at the Bronx Zoo. Whenever I tossed roaches or crickets in for the lizards, the Cottonmouths would move about in an apparent search for food. I’m wondering if youngsters consume insects as well; the closely-related Copperhead has been observed feeding upon cicadas and grasshoppers.

 

Cottonmouths under my care were fed minnows, shiners, trout, goldfish, mice and rats; I’ve always meant to try crayfish, but unfortunately did not. Like many fish-eating snakes, they seemed perpetually hungry. The opening of their exhibit door, with or without the scent of food, generally elicited a mad rush forward. All those I’ve kept adjusted well to captivity – thrusting them away with a snake hook did nothing to damper their desire to feed!

 

Additional Information

The name “Cottonmouth” arose from this species’ threat display – when cornered, it throws back its head and gapes widely to expose the cottony-white interior of the mouth. If this fails to dissuade the intruder, the snake strikes repeatedly. Basking animals usually drop into the water and swim away, either below or at the surface, when disturbed.

 

Classification of Cottonmouths and other Vipers

Cottonmouths and their relatives, collectively known as “pit vipers”, are placed in the family Viperidae and subfamily Crotalinae, along with palm vipers, rattlesnakes, copperheads and related species. They are considered to be the most advanced, or highly evolved, of all snakes.

 

Crotalids, or pit-vipers, possess a sophisticated sensory organ (the “pit”) that detects the infra-red rays produced by birds and mammals. Located between the eye and nostril, this organ is far more sensitive than the heat receptors that have evolved among the boas and pythons. The arrangement of the heat receptors within the pit viper’s sensory organs are replicated in the brain and integrated with visual information received there. The pit may thus be considered more of an “imaging device” than mere heat receptor, and likely provides detailed information concerning the size and shape, as well as location, of warm-blooded animals. Aided by these unique organs, pit vipers are able to hunt and escape predators even in complete darkness.

 

Vipers possess long, hinged fangs that fold back against the roof of the mouth when not in use. Venom is injected with a single bite, in the manner of a hypodermic needle. The snake then retires and allows the prey to run off, and follows its scent trail once the stricken animal has expired. This strategy spares vipers the injuries that can be inflicted by prey animals upon snakes such as cobras, which must hold on while injecting venom. When attacking frogs, fish and other relatively benign prey, however, Cottonmouths hold onto the animal after striking.

 

 

Further Reading

The World’s Largest Rattlesnake

Keeping Watersnakes

 

 

The Red-Eared Slider (Trachemys scripta elegans) is without question the world’s most commonly-kept pet turtle. But while these attractive reptiles are extremely responsive to people, many novice owners underestimate the amount of care and space their upkeep requires…and do not realize that Sliders commonly live to age 20+, and often well beyond. Over time, these factors lead many people to release or re-home their once beloved pets. As a consequence, Sliders have become established, in the wild, in dozens of US states and in countries ranging from Brazil to South Africa and Japan, where they are causing ecological havoc. Turtle adoption services and reptile rescues house literally thousands more unwanted pets. Please read this article carefully before buying or adopting a Red-Eared Slider, and be sure to post any questions below. Please also see the linked articles on the care of Sliders, Map Turtles and similar species.

 

Aquarium Size and Upkeep

Female Sliders reach 8-12 inches in length. I personally measured one that was just over 12 inches long…and 11 ¾ inches wide! Males generally top out at 6 inches, but both sexes are very active, and will languish in cramped quarters. An adult female will require a 75-100 gallon aquarium, a commercial turtle tub, or a wading pool. Pairs rarely do well together, as the overly-amorous males constantly harass the objects of their desire with mating attempts.

 

Turtles are messy feeders and very hard on water quality. Powerful filters help, but even so partial or total water changes will be necessary. If a large plastic storage container is used as a home, it must be emptied and cleaned several times weekly.

 

Cost

With so many being up for adoption, Slider ownership might appear to be a good deal. But the initial purchase price of any reptile is generally the smallest of the related financial considerations. In addition to large and expensive aquariums and filters, Slider ownership entails electricity use, veterinary care, and the purchase of UVB bulbs and fixtures, heat bulbs and fixtures, water heaters, basking platforms, food, and mineral supplements.

 

Veterinary Care

Veterinarians willing to treat reptiles are difficult to find in many regions, although those experienced in turtle care are becoming more common. It is always a mistake to obtain a reptile of any kind before locating a veterinarian, or to imagine that even the hardy Slider will not require medical care at some point. Veterinary costs for reptiles are comparable to those charged for dog or cat care.

 

Longevity

Sliders routinely reach age 20 in captivity, and have the potential to live much longer. The published longevity record is 41 years, but I’m quite sure, judging from experience with related species, that there are some that have exceeded the half-century mark. That cute little hatchling you bought for your child may become your (much larger!) responsibility when she or he goes off to college.

 

Health Considerations

Salmonella bacteria, commonly present in turtle digestive tracts, can cause severe illness in people. Handling an animal will not cause an infection, as the bacteria must be ingested. Salmonella infections are easy to avoid via the use of proper hygiene, but are a serious concern for children and elderly or immune-compromised adults. Please speak with your family doctor and see the article linked below for further information.

 

Slider Alternatives

Several Map and Painted Turtle species share the Slider’s lifestyle, good nature and hardiness, but do not grow quite as large. Common Musk Turtles, Eastern Mud Turtles and a number of their relatives are even smaller, and do not need a source of UVB radiation. All make great pets, and become quite responsive to people. There are a great many other possibilities as well…please see the linked articles and post below for further information.

 

 

 

Further Reading

Common Musk Turtles in Captivity: the Perfect Pet Turtle

Slider, Map and Painted Turtle Care