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

Introduction
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.

An article concerning the natural history and pest status of flour beetles is posted at:
http://www.google.com/search?hl=en&as_q=confused+flour+beetle&as_epq=&as_oq=&as_eq=&num=10&lr=&as_filetype=&ft=i&as_sitesearch=&as_qdr=all&as_rights=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=images

Introduction
Although 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.

You can read more about the natural history of Tokay geckos and related species at:
http://www.tigr.org/reptiles/search.php?submit=Search&genus=Gekko

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.

The 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.

An interesting article on Florida’s introduced Nile monitor lizards is posted at:
http://www.naherpetology.org/pdf_files/292.pdf

Introduction
Herpetologists 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
All 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.

Diet
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.

Habitats
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.

Harvard biologist David Blachurn knew he was onto something unusual when a benign-looking frog he was examining in Cameroon, West Africa kicked out and left him with a bleeding cut.  Unusual indeed – an article  (23 August 2008) in Biology Letters describes the hidden claws of Perret’s night frog as the only vertebrate claws known to break through the skin in order to become functional.  Some, or possibly all, of the other 10 frogs within the genus Astylosternus are also equipped with skin-covered claws on their toes (the fingers are clawless).

The frog’s sharp, curved claw is actually the last bone of the toe, and pierces the toe’s skin when a specific tendon is flexed.  It is assumed that the claw retracts after use and the skin heals, but further study is needed.  Other amphibians that experience “self-inflicted” wounds include the Surinam toads, Pipa spp., whose young push through the skin of the female’s back when ready to swim off on their own and the ribbed newt, Pleurodeles waltl.  The ribs of this newt pierce the skin of the back, carrying toxins with them, when the animal is threatened.

Despite the massive trauma caused by the emergence of 80+ fully formed little frogs, the skin of breeding Surinam toads (P. pipa) under my care appeared well-healed within 24 hours.  I’m sure there are some compounds that may be of medical use to people hidden in the body chemistry of this and other amphibian species.

Of course, people living within the habitat of Perret’s night frog have long known of its odd defense and even utilize specially-constructed spears when hunting it, to avoid being injured.

The only other frogs known to have claws are members of the family Pipidae – the various African clawed and dwarf African clawed frogs.  I have observed both putting their claws, which are always exposed, to interesting uses (more to come in future articles).

You can read more about this frog and related species at:
http://research.amnh.org/herpetology/amphibia/references.php?id=1191