The Natural History and Captive Husbandry of the Taiwan Beauty Snake or Chinese Ratsnake, Orthriophis (formerly “Elaphe”) taeniurus friesei

Taiwan Beauty SnakeI’ve never quite understood why the aptly named Taiwan beauty snake did not soar in popularity as soon as it entered the pet trade. I was captivated by them from the moment I began looking after a group at the Bronx Zoo some 15 years ago, and added the species to the Staten Island Zoo’s collection when working on the reptile house renovation there. Today, these arboreal constrictors are beginning to receive some attention from hobbyists, and captive born young are frequently available.


Taiwan beauty snakes are placed within the family Colubridae, and until recently were classified in the genus Elaphe, along with the corn, black rat and similar North American snakes that they superficially resemble. Eight to nine subspecies have been identified, but interbreeding where their ranges overlap complicates taxonomy. The group is often loosely referred to as the Asian ratsnakes.

Physical Description
The background color of these gorgeous snakes is yellowish tan/brown to olive, and a pair of joined black spots and smaller blotches mark the back. Along the last third of the body the color pattern abruptly changes – from here the snake is boldly marked with a band of yellow and 2 black stripes. Smaller blotches cross these, and a black stripe extends from the eye to the mouth’s corner. The ventral surface is creamy-white speckled with black.

The tail is highly prehensile, allowing for long strikes at fast-moving, arboreal prey.

This largest member of its genus averages 5-6 feet long, but occasionally approaches 9 feet in length.

This subspecies is native to the island of Taiwan, but is possibly introduced to mainland China. Related subspecies range throughout much of India, China, Southeast Asia and Japan’s Ryukyu Islands.

This snake and its relatives, most of which are quite colorful, are sometimes kept in rural homes and barns for their rodent-catching abilities. This has resulted in range expansions for a number of beauty snake subspecies. As individuals are highly variable in appearance, and the subspecies readily interbreed, the taxonomy of the genus is unclear.

Taiwan beauty snakes are quite adaptable, being found in forests, open woodlands, overgrown fields, swamps and suburban areas. If unmolested they will take up residence in barns, rural homes and agricultural fields. All beauty snakes are highly arboreal but will descend to the ground to hunt.

Status in the Wild
The wild status is largely unstudied, but it is known that the Taiwan beauty snake is hunted for the food, skin, pet and medicinal trade. However, it adapts well and may even benefit from some human presence, frequenting farms, trash dumps and abandoned buildings in search of rodents. Some range expansion has likely occurred via people who transport this snake (and related subspecies) from place to place as a rodent control measure.

Squirrels, rats, mice, bats and other small mammals, birds and their eggs; hatchlings feed largely upon treefrogs and lizards. Prey is overcome by constriction.

The 6-10 eggs are laid in May-June, but other than that reproduction in the wild is not well documented. Please see below for captive breeding information.

The Taiwan beauty snake’s threat display is very impressive – it compresses and inflates the first third of its body and rears up in an “S” shaped coil while facing the enemy and striking repeatedly.

Please check back Monday for information on the captive husbandry requirements of Beauty Snakes.

Image referenced from Wikipedia. First published by MSP.

Flour Beetles (Confused or Rice Flour beetles, Tribolium confusum and Red Flour Beetles, T. castaneum) – a valuable food for small amphibians and reptiles

Flour beetles of various types are serious pests in grain product storage facilities, and those discussed here are worldwide in distribution.  However, the traits that make them successful invaders also render them easy to culture in captivity.

The larvae, or grubs, of the beetles offer an easy way to add nutritional variety to the diets of tiny reptiles and amphibians, most of which must subsist on only a few food items in captivity.  The adult beetles release an irritating gas when disturbed, but are none-the-less consumed by some reptiles and amphibians.

Obtaining Flour Beetles
I was first introduced to flour beetles some 20 years ago by Bob Holland, an amphibian expert who was setting longevity records with poison frogs long before most zoos kept any at all.  In those days, we collected our founding stock by searching through old containers of dry dog food and cereal.  Today, cultures of confused and red flour beetles are available from private breeders and biological supply houses.

Culturing Flour Beetles
Although most beetle breeders advise keeping the animals in a mix of flour and yeast, Bob’s method of rearing them in dog biscuits has worked very well for me.  The problem with a flour mix is that the medium must be sifted through a fine net each time larvae are needed, which leaves one with unwanted beetles, pupae and shed skins.

Dog biscuits provide all the food, moisture and shelter needed by the beetles (be sure to crack open the biscuits to give the beetles easy access to the interior).  When larvae are needed, I simply tap a biscuit over a Petri dish.  The larvae can also be concentrated by tapping several biscuits over a separate container, into which only 1 biscuit has been placed.  All the grubs will eventually gravitate to the 1 biscuit, allowing you to collect many in a short time.

Using Flour Beetles
The adult beetles live for approximately 1 year, with the period from egg to adult being 4-6 weeks, depending upon temperature.  The larvae are 3/16th of an inch long when fully grown – an ideal size for poison frogs, harlequin frogs and newly morphed froglets of small species such as spring peepers.  I have also fed them to red-backed and red salamanders, the larvae of various newts and to small granite night lizards.

Please write in with your own experiences, tips and questions.  Thanks, until next time, Frank.

An article concerning the natural history and pest status of flour beetles is posted at:

An Accomplished Lizard Vocalist – the Tokay Gecko, Gekko gecko

Tokay GeckoAlthough many lizards are quite vocal, perhaps none is so capable and well known as the Tokay gecko.  In fact, the species draws its common name from the loud cries of “Tokay! Tokay!, given (most often in the wee hours of the morning) by the extremely territorial males.  Ranging throughout much of south and Southeast Asia, and introduced to Hawaii, Florida and Martinique, the Tokay does not mind human company.  It is often more common in homes and other buildings than in more natural settings, even within such bustling cities as Hong Kong and Miami.

Rentable Geckos?
Tokay geckos are aggressive, 12 inch long predators, and do not hesitate to tackle small snakes, treefrogs, other lizards, nestling birds and mammals.  Roaches are, however, particularly favored – a dietary preference that often endears them to their human hosts, despite their noisy ways.  Some years ago a pet store in New York City began renting them to customers for just that reason.  However, the geckos’ propensity to proclaim their territory via “song”, most often at 4 AM, and their willingness to bite (and unwillingness to release their hold!) doomed the scheme to failure.

Early Morning Singers
I once released a group of Tokay geckoes into a large zoo exhibit as a roach control measure (well, to be honest, mainly because I liked to watch them go about their business at night – few lizards can keep up with roach reproduction!).  In those days I was often at the zoo until all hours of the night, dealing with emergencies and satisfying my curiosity about the nocturnal goings on there.  As has been reported by sleepless gecko hosts worldwide, the males did indeed call most frequently (and vigorously) between the hours of 2 and 4 AM.

Please write in with your own vocal lizard stories.  Thanks, until next time, Frank.

You can read more about the natural history of Tokay geckos and related species at:

The Monitor Lizards (Family Varanidae) – Family Overview and Species Accounts, Part II

Click here: The Monitor Lizards (Family Varanidae) – Family Overview and Species Accounts, Part I, to read the first part of this article.

Monitor Intelligence
Monitor lizards exhibit an extraordinary degree of intelligence and retain what they have learned for long periods.  Gould’s monitors (V. gouldii) have been observed taking indirect routes when chasing rabbits.   Rather than running directly after the rabbit, they veer off in a direction that takes them away from the animal, but leaves the lizard in a position to intercept the rabbit at the mouth of its burrow!

Parentie monitors (V. giganteus) seeking animals hidden within burrows do not dig away at the burrow entrance (as would a foolish dog!) but rather sniff the ground several feet away.  Once they locate the underground position of their prey, they dig directly down to reach it, keeping an eye on the entrance as well.

An Experience with a Bright Monitor
I have often had the good fortune to observe monitor intelligence in action.  While working at the Bronx Zoo, I once looked up from a phone conversation to see a 6 foot long crocodile monitor (V. salvadorii) go shooting by, followed by an equally fast-moving coworker of mine.  We cornered the animal behind a large cage, where he remained as long as we were in view.  As soon as we moved off to either side, he cautiously peered around the cage and looked both right and left, to fix our new positions.  The lizard most definitely did not want either of us sneaking up on him, and made sure he saw both of us at all times.

Mangrove MonitorThe stout fellow was recaptured – with more wear and tear to us than he!  Monitors are incredibly strong – a 7 foot long water monitor (V. salvator) I worked with was able to move along with myself and 2 other strong men trying to pin him down – this despite being rather seriously ill.

Monitor Venom
In 2005, Dr. Bryan Frye and researchers at Australia’s Melbourne University discovered that several species of monitor lizards, including the Komodo dragon, V. komodoensis and the lace monitor V. varius, produce venoms of varying strengths.  Lace monitor venom was subsequently shown to cause the lizard’s prey to rapidly loss consciousness by affecting the blood’s pressure and clotting ability.

Until this discovery, bacteria in the mouth of the Komodo dragon were thought to be responsible for the quick onset of death seen in deer, goats and other large animals bitten by these lizards.  While such bacteria no doubt add to the trauma associated with a bite, it now seems certain that venom delivers the knockout blow.  A combination of venom and bacterial infection is also the likely source of the strong reaction often associated with bites inflicted by monitor lizards upon people.

The Bearded Dragon, Pagona vitticeps, a popular pet species not related to the monitor lizards, was also shown to produce mild venom – other members of the lizard family Agamidae are being studied.

Onto popular monitors, large and small, next time.  Until then, please write in with your questions and comments.  Thanks, Frank

An interesting article on Florida’s introduced Nile monitor lizards is posted at:

The Monitor Lizards (Family Varanidae) – Family Overview and Species Accounts, Part I

Larry the Nile Monitor from Forgotten Friend Reptile SanctuaryHerpetologists and hobbyists alike have long known that there is something “different” about the family of lizards known collectively as “monitors” (or, in Australia, “goannas”).  One cannot observe a monitor for long without getting a sense of the animal’s intelligence – they scrutinize the world differently than do other reptiles, and their reactions to new situations are surprisingly quick and complex.  Recent studies have confirmed that monitors are unique, and, in many ways, the most intelligent and advanced of the lizards.

In years past pet keepers were limited to a very small number of monitor species from which to choose.  An explosion of interest in the group has radically changed that situation, and today animals rarely seen even in zoos are being commercially bred in huge numbers.  Happily, there are monitors even for those without much room – and the very smallest types still exhibit true monitor behavior, intelligence and “attitude”.

Today I’ll present an overview of the group as a whole.

Species Diversity
Sixty eight species of monitor lizards, all classified within the family Varanidae and the genus Varanus, range across Asia, Africa and Australia.  Although generally associated with warm climates, one species, the desert monitor (V. griseus) may be found as far north as Kazakhstan – at roughly the same latitude as southern Vermont.

In Australia, where over 2/3 of the world’s species are found, monitor lizards have evolved to fill a wide range of ecological roles held elsewhere by other lizards and by large, predatory birds and mammals.  Huge Australian species such as 8 foot long parentie monitor, V. giganteus, and the lace monitor, V. varius, are the dominant predators in their habitats,  as are Komodo dragons, V. komodoensis, on the islands of Komodo, Padav, Rinca and Flores.

At 8 inches long, the short-tailed monitor, or pygmy goanna,
V. brevicauda, is the smallest member of the group.  The infamous Komodo dragon is the world’s largest lizard.  It occasionally tops 10 feet in length, but is dwarfed by extinct monitor species which may have measured over 20 feet long.

General Physical Characteristics
Water Monitor Eating a FishAll monitors share a similar body plan – a long neck and relatively small head, sturdy body and limbs and a long, powerful tail, and most measure in the range of 2 to 5 feet in length.

The tongue is deeply forked and is flicked out repeatedly.  As with snakes, the tongue carries airborne chemical cues to the Jacobson’s organ, thus conveying information about the environment and other animals.

Male monitor lizards compete for females by grappling, often rising onto their hind legs during tests of strength.  All species lay eggs.

All monitors are alert, effective predators, with the various species taking an incredibly huge array of prey – termites and other insects, snails, spiders, crayfish and other invertebrates, birds and their eggs, frogs, turtles, snakes, hatchling crocodiles and other reptiles and amphibians, and rodents, weasels, tree kangaroos and other mammals to the size of adult deer.  Large monitors living near developed areas also prey upon domestic dogs, cats, chickens, ducks, pigs and goats, and consume carrion and offal as well.  The Philippine monitor lizard, or bataans (V. olivaceus), is unique in feeding upon fruit at certain times of the year.

On rare occasions, the Komodo dragons have attacked and killed people.  In fact, current restrictions on the long-held tradition of feeding goats to these huge lizards (a tourist attraction with possible links to local religious beliefs) is possibly at the root of the recent rise in attacks on people and livestock.

Monitor lizards have evolved to occupy a wide variety of habitats – there are arboreal specialists, such as the green tree monitor, V. prasinus, aquatic species such as the mangrove monitor, V. indicus, and grassland dwellers such as the savanna monitor, V. exanthematicus.  There are also many generalists – Gould’s monitor, V. gouldii, a large lizard that occupies nearly all of Australia, is equally at home in grasslands, open forests, river valleys, cliff-sides, semi-deserts and nearly all other habitats within its huge range.

The Nile monitor, V. niloticus, is native to sub-Saharan Africa but is now thriving in southern Florida, where released pets have established breeding populations.  Approaching 7 feet in length, this aggressive predator is severely impacting the local ecology by out-competing and preying upon a wide variety of native species.

Wide-Ranging and Isolated Species
The size of the ranges of the different species varies greatly in extent.  For example, the blue tree monitor, V. macraei is limited in distribution to Batantan Island off Papua New Guinea while the 9 foot long Asian water monitor, V. salvator, is found from India through Bangladesh, Myanmar, southern China, Vietnam, Laos, Cambodia, Thailand, the Philippines, Malaysia and Indonesia.

Check back Friday for the conclusion of this article. And be on the lookout for more monitor articles in the future. Please let me know any feedback or comments you may have.


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