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

 

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.

 

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.

 

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.

 

 

Further Reading

Chameleon Color Change: Advertising and Camouflage

 

Chameleon Basking Influenced by Vitamin D Levels in Blood

Veiled Chameleon Care

 

 

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)

 

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.

 

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.

 

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.

 

 

 

Further Reading

 

 

Providing career advice is one of the most rewarding aspects of my work.  There are many resources available to aspiring zoologists and herpetologists, but deciding the best path to take can be a confusing process.  Today I’d like to provide some guidelines drawn from my experiences and those of my readers and colleagues on how to become a zoologist.  And as you’ll see from the face of the little fellow in the photo below, it’s great fun to get started early!

Note: Much of the following information is based on my work in zoos and museums, and the journals mentioned are oriented towards herpetology.  However, the basic principles apply to any discipline within the field of zoology.  I can also help, or refer you to others who can help, with related fields, such as ornithology, arachnology, etc.  Please post any questions you might have below.

 

Speak with People Working in the Zoology Field

Education continues to play a key role in attaining a career in zoology.  But what hampered me most – and I see this in many others who are interested in working with animals – was my shyness around teachers, professors and practicing zoologists.  Most successful colleagues of mine worked closely with their teachers and college professors, and were quick to speak to the zoologists they encountered at conferences or while visiting zoos and museums.  I’ve found that most professionals recall their own struggles, and are quick to provide advice to others.

 

Zoos and Aquariums

Zoo-keeping is a common entry point for folks wishing to work with animals.  Once employed, one can continue to work towards an advanced degree (I completed my Master’s Degree in this manner) and eventually qualify for research or related positions as a zoologist; financial support for continuing education is sometimes available at major zoos.  You’ll need a B.S. for an entry level animal-keeping job at larger zoos (in some cases, extensive experience may be substituted); an M.S. to move into other areas, and a PhD for curatorial, field research, and similar positions.

While it may be easier to rise up the ranks in smaller zoos, large well-funded institutions generally offer more career options. Zoo-keeping is a wonderful job for animal enthusiasts, and many quickly become enamored of it (myself included).  Unfortunately, salaries are abysmally low, especially given the education required, and particularly if you live in or near a large city.  Some zoos have a policy against promoting keepers to positions above the supervisory level.  However, a keeper position in a large, well-respected zoo often becomes a stepping stone to curatorial spots elsewhere.

Field Research

Fieldwork was a favorite of mine, but I became involved as an aside to my work as an animal keeper and supervisor.  Those who pursue fieldwork as their profession often work “from grant to grant” – not an easy route to follow, but some enjoy the lifestyle.  The Bronx Zoo and certain others employ fulltime field researchers, generally PhD’s or graduate students.

Aspiring field researchers sometimes go into fulltime teaching at universities, thereby locking in a steady paycheck, and then become involved in research, perhaps supported by the college, during the summer.

Zoologist Salary

Zoologist salaries at museums, zoos and other not-for-profit institutions are generally lower than what similarly-educated professionals earn in the private sector.  Faculty teaching or research positions at colleges and universities vary with the reputation and funding base of the institution.  However, positions with well-respected educational or research institutions can lead to lucrative employment elsewhere, and upper-level spots in such institutions can be financially rewarding.

 Federal and state governments employ zoologists in a wide variety of capacities.  Salaries vary by job title, education attained and experience, but are commensurate with those of other similarly-employed professionals.

 Experienced zoologists often supplement their income by consulting with government agencies or private companies, teaching, writing books, lecturing, free-lance field research, leading wildlife viewing tours, and similar activities.  As one gains experience, a variety of interesting opportunities usually arise.

Remember also that there are many related fields that may offer much more in the way of salary than do typical careers in zoology, including bio-medical research (medicine from frog skin, etc.), agricultural pest research, and conservation genetics.  Zoologists are also needed as researchers in most fields dealing with human physical and mental health, and many, many others that at first glance seem unrelated to the study of animals.

Colleges for Those Interested in Zoology

The following is provided as an example of what to look for in general…please post below for information on related fields.

A major in biology or zoology is usually ideal (you can always specialize as time goes on), but individual schools may be able to provide other options …it is very important to discuss your plans with high school or college career counselors.

Please see this site for a list of colleges offering herpetology courses.  Colleges offering courses and majors in entomology and other related fields are in greater supply, and should be easy to locate…please post below if you need assistance.

Professional Zoology and Herpetological Journals

Reading professional journals was a “secret” I discovered early-on (thanks to the advice of my dear cousin, a librarian).  This habit gave me an edge over others, and continues to serve me well…and it’s very enjoyable!

While much of what you encounter may not be relevant to your interests, pursuing even the abstracts alone will give you important information, i.e. what is being done and by whom, subjects in need of further research, the types of articles likely to be published, which colleges and zoos support researchers, etc.  You may also find that interesting work is being done nearby…by following up, you may find a volunteer opportunity and make important professional connections.  It’s never too early to begin.  With so much (often questionable) information available online, much of it written in a very casual style, I believe it is very important for young people to take note of what will be required if they pursue a career in zoology.

Major professional journals are often expensive.  Please see Professional Herpetological Journals and Organizations, Part I and Part II
for descriptions of the leading herpetology journals).  However, you can keep abreast of article abstracts through a valuable, free resource – Bioone.org. Simply choose the journals that interest you and sign up for email notifications.  You’ll receive abstracts of all new articles, and have access to past editions.  Hundreds of journals, including all the leading ones, are available.

Fortunately, full issues of some newer professional journals are now available free online.  Please post below if you would like further information on these.

Volunteering

Volunteering for biology professors, field researchers, zoos, nature centers and museums can provide you with invaluable experience and connections.  Most are under-funded, and often gladly accept responsible offers of assistance.

It’s also useful to become a member of local zoos, museums and special interest groups such as birding clubs and herpetological societies.  Be sure to attend lectures given in your area of interest, and speak with the presenters if possible.  Local groups can also provide amazing opportunities to meet people and become involved in interesting projects; the New York Turtle and Tortoise Society, my favorite, is a perfect example.  Zoos and museums nearly always utilize volunteer interns (I started out at the Bronx Zoo in this way), so be sure to look into these possibilities.

Zoologist Job Listings and other Resources

The American Zoo Association job list will give you an idea of the types of positions available at zoos; field research and museum opportunities are sometimes included.

Careers in Herpetology, Part I

Careers in Herpetology, Part II

American Society of Ichthyologists and Herpetologists: Job Listing

Center for North American Herpetology: Careers in Herpetology and Herpetoculture

Society for the Study of Reptiles and Amphibians: Careers in Herpetology

 

 Further Reading

Volunteer Opportunities, Field Research

Becoming a Licensed Wildlife Rehabilitator

 

The USA’s resident Green Anole, Anolis carolinensis, is one of the most familiar of all reptilian pets, and introduced many of my generation to reptile-keeping.  Less well-known (in fact, largely ignored!) are two equally beautiful, green-colored, color-changing anoles that that have become established in the USA in recent years (in and around Miami, Florida…no surprises there!).  Both of these active, interesting lizards – the Cuban Green Anole, A. porcatus, and the Hispaniolan Green Anole, A. chlorocyanus – will be instant hits with anole enthusiasts, especially those of us who still favor the “original” Green Anole over all others.

Natural History

The Cuban Green Anole inhabits Cuba, Isla de la Juventud and the Dominican Republic; a feral population is established in and around Miami, Florida. Two subspecies have been described.

The Cuban Green Anole resembles the Green Anole in size and shape, but exhibits a more complex array of colors, with various shades of green and brown often being present at the same time. A variety of dark brown to black lines and spots may also be present, and some individuals are speckled with blue and gold.

The Hispaniolan Green Anole is, as you might guess, native to Hispaniola (Haiti and the Dominican Republic) and several small offshore islands.  Introduced populations are established near Miami, Florida, and in Surinam.  Two subspecies are known.

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 Not a week – much less a year – passes without an exciting new herp species being discovered.  Included among this year’s surprising finds are the world’s smallest vertebrate, geckos and frogs isolated on mountaintops for millions of years, a “political” snake, and legless lizards living in and near major US airports and cities.  Please also check out the linked articles to read about large, colorful monitor lizards and other awe-inspiring creatures that were brought to light in the past few years.  Following is just the tip of the iceberg…please be sure to post your own favorite finds below.

New Reptile and Amphibian Species in 2013

The World’s Smallest Vertebrate

The distinction of being the smallest creature with a backbone generally shuffles between frogs and fishes (the world’s smallest snake, which can coil up on a dime, is also very impressive).  This year, a tiny Southeast Asian fish that held the title since 2006 was nudged out by a Microhylid frog, Paedophryne amanuensis (shown here sitting on a dime, with room to spare!).  Endemic to Papua New Guinea, adults can be as small as 0.28 inches, while the largest individuals barely top 0.3 inches.  But packed into their minute bodies are lungs, a brain, liver and all other such organs (they do have a uniquely-reduced skeleton, however – compromises must be made!).  By contrast, the Blue Whale, world’s largest vertebrate, tops out at approximately 90 – 100 feet in length.
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