Vitamin D3, UVB and Pet Reptiles: Important New Information for Pet Owners

Brown Anole

Uploaded to Wikipedia Commons by Hans Hillewaert

We’ve long known that many reptiles need Ultra Violet B (UVB) light exposure in order to manufacture Vitamin D3. Vitamin D3, which is essential for proper calcium uptake, is also present in many foods, and some reptiles can utilize it in this form.  However, there are some gray areas.  It seems that reptiles long considered incapable of using dietary D3 (and which therefore need UVB light exposure), can sometimes obtain D3 from their diet (please see chameleon and day gecko articles linked below).  Generalizations can be misleading – for example, the study summarized below shows that two anole species sharing the same habitat obtain D3 in very different ways.

 

Anole Study – Vitamin D3 and Basking Behavior

A study recently published in the Journal of Herpetology [47 (4) 524-29, 2013] examined whether the level of Vitamin D3 in the diet would affect the basking behavior of two anole species.  Earlier research had shown that Panther Chameleons do alter their basking behavior in response to blood levels of Vitamin D3; please see the article linked below for details.

 

Wild and captive Brown Anoles, Anolis sagrei and Stripefoot Anoles, A. lineatopus, living in Jamaica were used as study subjects.  When the D3 content of the diet was increased, Brown Anoles decreased the amount of time they spent basking in UVB light.  This remained constant over a 6 week period.  This indicated that they were obtaining enough D3 from their diet. When the dietary D3 was decreased, the Brown Anoles increased their exposure to UVB, so as to be able to manufacture D3 in the skin.

 

Stripefoot Anoles, on the other hand, did not decrease their basking time when fed high levels on D3, and they did not increase basking behavior when fed diets low in D3.

 

The researchers therefore concluded that Brown Anoles are able to use dietary D3, while Stripefoot Anoles cannot.  Stripefoot Anoles seem to rely upon the Vitamin D3 that is produced in their skin when it is exposed to UVB light.

 

Studies such as this show us that we must carefully research the needs of each species under our care.  Even if they are closely related, and share similar habitats, diets, and lifestyles, captive conditions that work for one could spell doom for another.

 

Madagascar day Gecko

Uploaded to Wikipedia Commons by Manuel Werner, Nürtingen, Germany

My Experience: Day Geckos Without UVB Did Well

I’ve made some related observations on Madagascar and Standing’s Day Geckos.  UVB exposure has generally been considered critical to their welfare in captivity.  Yet a colony of both, living at semi-liberty in a large zoo aviary, seems to be doing very well without access to UVB light.  Please see the article linked below for further details.

 

Providing UVB to Lizards and other Reptiles

Natural sunlight is the best source of UVB, but it is important to bear in mind that overheating can occur quickly, and that UVB does not penetrate glass or plastic.  Reptiles housed or placed outdoors must also be protected from rats, raccoons, dogs, cats, crows and other predators.  Where conditions permit, screen cages offer a great means of providing natural UVB to your pets.

 

t255908UVB Bulbs

In recent tests, the Zoo Med 5.0 and 10.0 Bulbs were found superior to several other models.  Mercury vapor and compact florescent bulbs generally emit higher levels of UVB than traditional florescent bulbs, and they broadcast it over greater distances.  Mercury vapor bulbs also produce heat, and so may eliminate the need for an additional heat source.

 

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly.  Thanks, until next time, Frank Indiviglio.

 

Further Reading

Chameleon Basking Behavior Influenced by UVB Needs

My Notes: Day Geckos Thrive Without a UVB Source

Using Compact UVB Bulbs

 Using Screen Cages

 

Keeping the USA’s Longest Snake: Eastern Indigo Snakes as Pets

Eastern Indigo Snake

Uploaded to Wikipedia Commons by Arjuno3

Hi, Frank Indiviglio here.  I’m a herpetologist, zoologist, and book author, recently retired from a career of over 20 years with the Bronx Zoo.  The magnificent Eastern Indigo Snake, Drymarchon couperi, is the longest of all snakes native to the USA, but occupies one of the smallest ranges.  These facts, along with stunning coloration and its reputation as a responsive pet, place the Indigo on the wish lists of serious snake keepers and zoos worldwide.  I had the good fortune to assist with an Eastern Indigo breeding/release program headquartered at the Bronx Zoo, which was both fascinating and frustrating.  Today I would like to pass along some thoughts on its natural history and captive care.

Description

The Eastern Indigo Snake is among the longest of all North American snakes; in the USA, only the Bullsnake, Pituophis catenifer sayi, regularly rivals it in size.  Robust and alert, the Eastern Indigo Snake averages 5-6 feet in length, with a record of 8 feet, 5 inches.  The glossy, blue-black coloration is unique to this species.  Some individuals, greatly favored in the pet trade, sport heads and chins highlighted by a reddish tint.

Natural History

The Eastern Indigo Snake is restricted to southeastern Georgia, southeastern Mississippi, and Florida.  Although coastal dunes, Palmetto scrub, agricultural areas and marsh fringes are colonized, healthy populations seem to require large expanses of longleaf pine forest and similar upland environments.  Human development within prime Indigo habitat has severely threatened this species’ future.  Today, only captive-born individuals may be legally sold, but over-collection was a severe problem in the past.

The Texas Indigo Snake (D. corais erebennus) ranges from southern Texas to central Mexico, while other relatives, known as Cribos, inhabit Central and South America.

Read More »

Are Tarantula Bites Dangerous? Sometimes Yes, According to New Study

Are Tarantula Bites Dangerous? Sometimes Yes, According to New Study

 

P regalis

Uploaded to Wikipedia Commons by Morkelsker

Hi, Frank Indiviglio here.  I’m a herpetologist, zoologist and book author, recently retired  from a career of over 20 years with the Bronx Zoo.  I’ve worked with thousands of tarantulas, in zoos and my own collection, for over 50 years.  In all that time, I’ve never been bitten…mainly because I do not handle them!  Tarantulas certainly adjust to captivity, but they can in no way be “tamed” or “trusted not to bite”…videos and statements to the contrary should be ignored.   Cases involving muscle spasms, chest pain and other severe reactions requiring hospitalizations were reviewed in a recent study – I am aware of similar cases involving colleagues working in the field.  The urticating hairs of New World tarantulas are also a consideration; some years ago, a co-worker of mine required corneal surgery to remove those shed by a Red-Kneed Tarantula.

 

Indian Ornamental Tarantula Bites

In a recent incident reported in the journal Toxicon (an excellent resource for those interested in venom and venomous creatures), a man in Switzerland was bitten on the finger while feeding his pet Indian Ornamental Tarantula, Poecilotheria regalis.  He felt little pain at the time, but experienced hot flashes 2 hours later.  Within 15 hours, he was hospitalized with muscle spasms and chest pain.  He was treated with muscle relaxers, but muscle cramps continued for an additional 3 weeks.

 

Researchers at the Swiss Toxicology Information Center became interested in the case and decided to investigate further.  They turned up 18 additional reports of severe reactions to the bite of the Indian Ornamental Tarantula (a/k/a Indian Ornamental Tree Spider) in their organization’s records and reported in medical journals.  Spider care websites contained anecdotal information about 18 other bites from the same species.

 

Most of the bites were to pet-owners’ hands, but thighs, cheeks and shoulders were also bitten (I imagine this to be the result of foolishly letting spiders wander about the body).  In 58% of the published cases, muscle spasms were suffered by bite victims.  Cramps continued for 1-4 weeks after discharge from the hospital.

 

Tarantula Venom

When corresponding with tarantula owners or training zookeepers, I always stress the fact that spider venoms are quite complex, and we that know very little about those of even commonly-kept species. Antivenin is, in most cases, not available.

 

P metallica

Uploaded to Wikipedia Commons by MLursus

Also, spider venom may evolve in response to the reactions of prey species, as has been shown to occur among many venomous snakes.  This may affect how bites should be treated, but specific information is scarce.  Venom composition (and, therefore, the necessary treatment) may vary among different populations of the same species…again as occurs in venomous snakes.  Individual sensitivities to tarantula venom, another unstudied subject, must also be considered.

 

As numerous species may be sold under the same common name, and exact identification is often difficult, it is critical that you ascertain the Latin names of any tarantula under your care.

 

Urticating Hairs

North and Latin American tarantulas shed tiny barbed hairs when agitated.  I saw x-ray images of such hairs imbedded in my co-workers eye (please see above).  At the time, I was undergoing a cornea transplant (non-spider related!), and being treated by the same surgeon who had operated on my co-worker.  According to the surgeon, tarantula hairs that work their way into the eye are extremely difficult, and in some cases impossible, to safely remove (in 2009, doctors were unable to remove the hairs of Chilean Rose-haired Tarantula from the eye of a victim in England).

 

P. subfusca

Uploaded to Wikipedia Commons by mistic

So please…enjoy observing and studying tarantulas, but do not touch them.  Please see the articles linked below for information on how to safely keep and transport these fascinating creatures. 

 

Snakes: Venomous Bites and Human Predation

Two surprising studies examining venomous snake bites and snake predation on humans:

 

Venomous Snakes Bite 4.5 Million People Each Year

 

People as Reticulated Python Prey: Study Documents 150 Attacks, 6 deaths in the Philippines

 

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly.  Thanks, until next time, Frank Indiviglio.

 

Further Reading

Tarantula Care: Popular Species

Important Supplies for Tarantula Keepers

Interesting Tarantula Facts

Chameleon Color Changes Predict Winner before a Fight Begins

 

Uploaded to Wikipedia Commons by  Mamboben

Uploaded to Wikipedia Commons by Mamboben

My grandfather cautioned me never to bet on a boxing match, as they were even less predictable than horse races.  But where chameleon fights are concerned, it seems that picking a winner is a simple matter.  A recent study revealed that color intensity and the speed with which a male can elicit color changes accurately predicted the winner of an aggressive encounter.  Furthermore, different areas of the body are used to covey specific types of information.  Chameleons know this, of course…which is why most contests end without physical contact between competing males.

 

Camouflage, Display, or Both?

Years ago, chameleons were thought to change color primarily to camouflage themselves from predators and prey.  In time, we learned that temperature, health, stress levels, dominance and other factors also played a role.

 

In recent years, researchers at Melbourne University discovered that communication, not camouflage, was the driving force behind the evolution of chameleons’ amazing abilities.  However, their work revealed that camouflage is involved as well.  At least one species, Smith’s Dwarf Chameleon, Bradypodium taeniabronchum, changes color when a predator appears…and the degree of color change varies according to the type of predator it faces!  You can read more about both studies in the articles linked below.

 

Female Veiled Chameleon

Uploaded to Wikipedia Commons by Geoff

Colors Convey Distinct Message

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Veiled Chameleons, Chamaeleo calyptratus  (which are unsociable even by chameleon standards!) were the subject of a recent study that examined color change and aggression (Biology Letters, 2013; 9 (6)).  Researchers at Arizona State University photographed and analyzed 28 distinct areas on the bodies of male chameleons involved in aggressive displays with rivals.  The brightness of the colors exhibited in certain body stripes foretold which of the chameleons would make the initial approach towards the other.  Head color intensity accurately predicted the contest’s winner.  The speed with which the various color changes took place also affected the fight’s outcome.

 

The vast majority of the staged aggressive encounters ended without physical combat. The rare battles that did occur lasted a mere 5-15 seconds.

 

Why Quit Before the Fight Begins?

I’ve read elsewhere that color change takes a heavy toll, metabolically, on a chameleon.  I imagine that a male who can quickly summon up a variety of bright, intense colors is viewed by rivals as being healthy and vigorous, and therefore not worth tackling.  Similar considerations may influence mate choice as well.

 

Threat posture, C. namaquensis

Uploaded to Wikipedia Commons by Yathin S Krishnappa

Seeing as a Chameleon Sees

Chameleons and many other creatures do not perceive colors as we do.  The Arizona State University study was the first to examine the effects of color change “through the eyes” of an animal.  Using a process that I did not completely (or, truthfully, even barely!) understand, specialized cameras and information concerning chameleon visual sensitivity allowed researchers to measure colors as they are actually seen by chameleons.

 

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly.  Thanks, until next time, Frank Indiviglio.

Further Reading

Chameleon Color Change: Advertising and Camouflage

 

Chameleon Basking Influenced by Vitamin D Levels in Blood

Veiled Chameleon Care

 

 

Black Rough Neck Monitor Care and History

Although the Black Rough Neck Monitor, Varanus rudicollis, is rarely-seen in the wild, captive-bred individuals are often available.  This striking lizard utilizes a variety of very different habitats, so in a suitably large enclosure one can expect to see a many interesting behaviors.  This is definitely a species worth studying carefully, as we still have much to learn.  I’ve always wanted to feature them in large zoo exhibits, but was not able to drum up much interest, unfortunately.  Private keepers, however, have added greatly to what is known of this under-appreciated monitor.

Black Rough Neck Monitors remind me of Merten’s Water Monitors, Vanaus mersentsi, in general body form and especially in their ability to move about in trees, water and on land with equal ease (Note: the photo below is of a Merten’s Water Monitor; please click here for photos of Rough Neck Monitors)

 

Riverside rainforest habitat

Uploaded to Wikipedia Commons by Allie Caulfield

Range

The Black Rough Neck Monitor is found across a huge range that extends from southern Myanmar through Thailand and western Malaysia to Sumatra and Borneo, and also inhabits nearby offshore islands.  As it is difficult to observe, many believe that the range is greater than generally accepted.

 

Habitat

Although widely distributed, the Black Rough Neck has specific habitat requirements.  It seems restricted to rainforests near permanent water bodies and mangrove swamps.  Although believed to be highly arboreal, Black Rough Necked Monitors frequently forage on the ground and in the shallows of rivers and swamps.

 

Merten's Water Monitor

Uploaded to Wikipedia Commons by Jarek Tuszynski /

Description

The Black Rough Neck Monitor is stout in build and averages 3-4 feet in length, with some individuals reaching 5 feet.  The body color ranges from dark gray to nearly black; there is some evidence that different populations exhibit specific shades of gray or black.  The thick, pointed scales that encircle the neck are unique among monitors; I’ve not yet found a reputable published account of their function.  Extremely sharp claws (even by monitor standards!) assist it in climbing.

 

Enclosure

Like most monitors, Black Rough Necks are quite active, and will not thrive in close quarters.  Adults require custom-built cages measuring at least 6 x 4 x 6 feet; greater height is preferable.

 

Cypress mulch or eucalyptus bark may be used as a substrate.  Shy by nature, they are best provided with numerous caves, cork bark rolls and hollow logs in which to shelter, and stout climbing branches for climbing.  They prefer sheltering above ground (wild individuals often utilize tree hollows), so a cork bark roll or large nest box positioned among the branches would be ideal.

 

The cage should be located in a quiet, undisturbed area of the home, as Black Rough Neck Monitors are very aware of their surroundings and easily stressed.

 

Temperature

Black Rough Neck Monitors fare best when afforded a wide temperature gradient, such as 75-95 F; a dip to 70-73 F at night may be beneficial. The basking temperature should be kept at 120-140 F; some keepers go as high as 150F.  Incandescent bulbs http://www.thatpetplace.com/spot-day-white-bulbs may be used by day; ceramic heaters http://bitly.com/NSUMSq or red/black reptile “night bulbs” http://bitly.com/MS35s9 are useful after dark.

 

Provide your monitor with the largest home possible, so that a thermal gradient (areas of different temperatures) can be established.  Thermal gradients, critical to good health, allow reptiles to regulate their body temperature by moving between hot and cooler areas.  In small or poorly ventilated enclosures, the entire area soon takes on the basking site temperature.

 

Humidity

Humidity should average 60-85%, but dry areas must be available.  A commercial reptile mister will be helpful if your home is especially dry.  A water area large enough for soaking must be available.

 

Light

UVB exposure is essential.  If a florescent bulb is used (the Zoo Med 10.0 UVB Bulb is ideal), be sure that your pet can bask within 6-12 inches of it.  Mercury vapor and halogen bulbs broadcast UVB over greater distances, and provide beneficial UVA radiation as well.

 

tp35833

Diet

The few available studies and observations indicate that wild Black Rough Neck Monitors take a wide variety of prey animals, and that the diet may vary across the range.  Rodents, bats and other mammals, although consumed when available, do not comprise the bulk of the natural diet.  Wild individuals seem to feed primarily upon grasshoppers, roaches and other large insects, frogs, crabs, and snails.  Scorpions, termites, birds and their eggs, and fish have also been recorded as being consumed.

 

A rodent-only diet will not work well for Rough Necked Monitors. Youngsters should be fed largely upon roaches, super mealworms, snails, hornworms and other invertebrates, along with small whole fishes, un-shelled shrimp, fiddler and green crabs, crayfish and squid.  Mice should be provided once weekly, and hard-boiled eggs can be used on occasion.  All meals offered to growing monitors should be powdered with calcium, and a high-quality reptile vitamin/mineral supplement should be used 3x weekly.  I favor ReptoCal, ReptiVite and ReptiCal.

 

Rodents and whole fish can comprise 50% of the adult diet, with a variety of large insects, hard-boiled eggs, crayfish, squid, shrimp, snails and similar foods making up the balance.  Calcium and vitamin/mineral supplements should be used 1-2x weekly.  Large food items should be avoided; even where adult monitors are concerned, mice are preferable to small rats.

 

Temperament

Although not a species for beginners, Black Rough Neck Monitors adjust well to captivity when given proper care, and make fine, long-lived pets.  Initially shy, some learn to trust gentle caretakers, while others remain wary even after years in captivity.  A large, well-furnished cage will provide the security which is essential if they are to become approachable.

 

In common with all monitors, they are capable of inflicting serious injuries with their powerful jaws, long tails, and sharp claws.  Thick leather gloves should be worn when handling Black Rough Neck Monitors, as even tame individuals will cause deep scratches with their claws in the course of their normal movements.

 

Breeding:

A single male can be housed with 1 or 2 females, but they must be watched carefully.  The nesting area should be enclosed (i.e. a large tub or plastic storage container within a wooden box equipped with a single entrance hole) and stocked with 2-3 feet of a slightly moist mix of sand and top soil or peat moss.

 

Egg deposition generally occurs within 35-50 days of mating, but captive conditions can greatly affect the gestation period.  Clutches contain 4-15 eggs, which may be incubated in moist vermiculite at 85-90 F for 180-200 days.  Double and triple-clutching has been recorded. Hatchlings measure 8-11 inches in length and are attractively banded with yellow.

 

Please check out my posts on Twitter and Facebook.   Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

 

Please also post your questions and comments below…I’ll be sure to respond quickly.  Thanks, until next time, Frank Indiviglio.

 

Further Reading

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