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Anole Lizard Care, Facts & Behavior

Allison's Anole

Uploaded to Wikipedia Commons by Fil.Al

In terms of the sheer number of species and of individual animals, Anoles may be the most successful of all lizard groups.  Each year, herpetologists add several new discoveries to the total species count – which now stands at 388!  In Anole-rich regions, several seemingly-similar species manage to co-exist in the same habitat…and many thrive in and around towns, farms and even cities.  Their adaptability sometimes leads to staggering population densities, with up to 10,000 Anoles per acre being present on some Caribbean islands!  Intelligence may also play a role in their success, as is shown by this fascinating study .  Many herpers of my generation were introduced to reptile-keeping by the Green Anole, Anolis carolinensis…today we’ll take a look at the fascinating, diverse family to which it belongs.



The world’s 388 Anole species are classified in the family Dactylidae (formerly Iguanidae) and the genus Anolis. 



Most Anoles are alert and active, and nearly all have a streamlined body with long tails, limbs and digits.  Males have colorful dewlaps (areas of loose skin below the throat) that are erected during mating and territorial displays. Female Green Anoles, and those of several other species, sport smaller, less colorful dewlaps.  The body color is usually some shade of green, tan or brown, and many are capable of rapid color changes.


Leopard Anoles breeding

Uploaded to Wikipedia Commons by Nathalie Colucci

Anoles range in size from the various Twig Anoles, which barely reach 3 inches in length, to Cuba’s Knight Anole, A. equestris, an 18-inch long hunter of treefrogs, lizards, small snakes, and nestling birds.  The Grenada Anole, A. richardi, is also sizable, sometimes exceeding 12 inches in length.  Most Anoles, however, measure 6-8 inches when fully-grown.


Range and Habitat

Anoles range from the southern United States through the Caribbean and Mexico to Central and South America.  Mexico is home to over 50 species, while well over 100 occupy various Caribbean islands.  The USA has but a single native, the Green Anole.  However, it is by no means “Anole-poor”, as stowaways and released/escaped pets have resulted in the establishment of breeding populations of at least 9 foreign species!


In the USA, all introduced species except the Brown Anole are restricted to Florida, which is now home to Hispaniolan Green, Puerto Rican Crested, Barbados, Marie Gallant Sail-Tailed, Cuban Green, Jamaican Giant, Large-Headed, Bark, and Knight Anoles.  The highly adaptable Brown Anole has managed to extend its range into southern and perhaps central Georgia.  First documented in peninsular Florida in the 1940’s (and likely established earlier in the Florida Keys), the USA’s Brown Anole population is comprised of 2 interbreeding subspecies – the Cuban Brown Anole, Anolis sagrei sagrei and the Bahaman Brown Anole, A. s. ordinatus.


Anolis barbatus

Uploaded to Wikipedia Commons by Olaf Leillinger

While ground-dwellers are known, most Anoles are arboreal, with different species (often in the same habitat) favoring reeds, bushes, tree trunks, low limbs, and forest canopies.  Anoles have adapted to life in rainforests, dry forests, cities, farms, suburban yards, arid scrub, swamps, brushy grasslands, riverside thickets, and many other environments.  Some, such as the Cuban Brown Anole, may actually be more common around human dwellings than in their natural habitats.  This highly adaptable lizard has actually been observed to quickly change to an arboreal lifestyle after the introduction of a terrestrial predator (please see this article); many believe that it is also responsible for decline in Florida’s Green Anole population.


Anole Care and Feeding

Anoles make wonderful pets, as they are out and about by day, and usually quite active; their group dynamics will keep even the most experienced keeper fascinated.  Many breed year-round if properly cared for, and some may be housed with certain treefrogs, skinks and other animals.  However, the common opinion that Anoles are a “beginner’s” lizard does these fascinating creatures a great disservice.  All Anoles are highly-complex, and have very specific needs that must be met.  Without ample space and cover, proper temperatures, access to UVB and a highly-varied diet, they will not thrive.  Please see the linked articles for detailed information on their care, and be sure to post your questions and observations below.


t260596Anoles feed largely upon flies, caterpillars, spiders, beetles and other invertebrates, and many also take over-ripe fruit, nectar and sap.  Larger species, such as the Grenada and Knight Anoles, occasionally add smaller lizards, frogs and snakes to the menu.


Anoles are major food items for predators ranging from large spiders to small mammals and birds.  Therefore, most are instinctively wary, and they tend to remain high strung in captivity. While there are exceptions, few take well to handling.



Further Reading

How to Breed Green Anoles


Green Anole Natural History


Keeping Cuban and Hispaniolan Green Anoles

My Leopard Gecko Is Not Eating: What To Do



Adult female

Uploaded to Wikipedia Commons by Jerome66

When cared for properly, Leopard Geckos are among the most hardy and long-lived of all reptile pets.  But apparently-healthy geckos sometimes refuse to feed, or cut back on their intake, and there is still much confusion as to why this occurs.  My work with Leopard Geckos and hundreds of other species in zoos and at home has (I hope!) provided me with some useful insights into this problem.  Some involve areas that any good reptile keeper would investigate – environment, stress levels, disease – while others, such as the effects of circadian rhythms (“internal clocks”), are less obvious.


Winter’s Arrival and Internal Rhythms Regulate Eating

Leopard Geckos are native to southeastern Afghanistan, western India, Pakistan, Iraq, and Iran, where they inhabit desert fringes and arid grasslands.  In some parts of this range, temperatures rise to 100+ F in summer and drop below 32 F during the winter.  Wild Leopard Geckos living in environments that experience severe winters become dormant for several months each year, while those in milder regions may remain active (please see the article linked below to read more about their natural history).


While your pet is, no doubt, many generations removed from the wild, internal circadian rhythms may cause it to become lethargic and refuse food during the winter.  This can happen even if your gecko is kept warm and given a photo-period of 12-14 hours.  To confuse matters further, some reptiles enter dormancy when winter arrives in their native habitats…even if it happens to be summertime in their present home!  I’ve seen this among Indian Gharials (fish-eating crocodiles) 15 years removed from the wild, and in many others.  Captive Bearded Dragons also exhibit this type of behavior on occasion; please see this article.


leopard geckoUnfortunately, it’s not often possible to be certain that a pet has stopped feeding due to the effects of an internal rhythm, so be sure to check the other possibilities discussed below.


Next I’ll mention other things that should be checked if your gecko stops feeding, including husbandry (tank set-up, temperatures, diet, etc.), stress, and disease.  I’ve written on each of these in further detail in the linked articles.


Your Gecko’s Environment

As Leopard Geckos are nocturnal, it’s important to monitor nighttime temperatures, especially during the winter, when most people lower their home thermostats.  The ambient air temperature should range from 78-84 F, which can be maintained by a ceramic heater or red/black reptile “night bulb”; a below-tank heat mat should be positioned so that one corner of the tank is warmer (88 F) than the rest.  Be sure also to establish a thermal gradient (areas of different temperatures) so that your gecko can regulate its body temperature as needed.


tPG01794While Leopard Geckos often adapt to smaller enclosures than do other lizards, individuals vary in their response to crowding.  Moving your pet to a larger terrarium may help, and this will also make it easier for you to establish a thermal gradient (small terrariums tend to remain at the temperature of the basking site).


And, no matter how well-adjusted or bold your pet may be, it’s important to provide a dark, secure cave or other shelter.  Geckos forced to remain exposed often cease feeding.



Wild Leopard Geckos feed upon a huge array of invertebrates, while pets are often limited to 2-3 food items.  Dietary variety is important for health reasons.  But providing different types of insects can also incite new interest in feeding.  We see this most commonly in chameleons, but the enthusiasm your Leopard Geckos will show for novel foods will leave you with no doubt as to their value.  Please see this article to read more about adding silkworms, house flies, sow bugs, wild-caught insects and other important foods to your pet’s diet.


Stress Can Affect Eating

Geckos may be stressed by the mere presence of a dominant cage-mate, even absent fighting.  If you suspect aggression, observe your geckos after dark, when they will be most active (a red/black reptile bulb will prove useful).  Appetite-suppressing aggression is especially common among young geckos that are being raised in groups.


Locating the terrarium in a noisy part of the house, or where there are vibrations from machinery, may also depress appetites and contribute to other health concerns.


Disease and other Health Issues

Impactions from substrate swallowed with meals and Metabolic Bone Disease are two of the more common reasons that geckos cease feeding.


Other health concerns that have been identified include Hyperthyroidism, Eyelid Lining Retention (following shedding) and Cryptosporidiosis.  Internal or external parasites, and a host of other less common ailments, should also be investigated if your pet stops eating.  Please post below if you need help in locating a reptile experienced veterinarian.



Further Reading

The Leopard Gecko in the Wild


The Ideal Leopard Gecko Terrarium 


Cold Weather Tips for Reptile, Amphibian & Invertebrate Owners


Uploaded to Wikipedia Commons by Eric Johnston

Whether you keep a single, cold-hearty Common Snapping Turtle or a large collection of tropical lizards, frogs and tarantulas, cold winter weather brings certain challenges.  This is especially true for those of us who, in the interests of environmental and financial responsibility, do not wish to super-heat our homes in order to satisfy our pets’ needs.  While working at the Bronx Zoo, I always sought the advice of our staff electricians when faced with heating issues.  Today I’ll review what I’ve learned there concerning various types of heating devices, cage material and location, insulation and other topics that take on special importance when temperatures drop.


Seek Professional Advice

I always advise herp keepers facing extreme winters to speak with an experienced electrician.  Most of us know a great deal about our pets’ needs and the available heating products, but as “electricians” we are usually “self-taught” (not a term that should be used in connection with electricity!).  Incorporating an electrician’s expertise will save time, money and, most importantly, assure our safety.


Concerning safety, please be aware that free-roaming dogs, cats, ferrets, tortoises, iguanas and other pets cause a number of fires each year (pushing papers and other flammable items close to heaters and bulbs, knocking over heaters, etc.).  I have first-hand knowledge of several such incidents, as well as others caused by improperly-located heat bulbs…please exercise caution.


Be sure to show your electrician the bulbs and other equipment that you use, and request guidance concerning safe distances from plants and other flammable objects, extension cord use, etc.  Don’t forget thermostats and rheostats – I was surprised to learn that these can sometimes drain enough power to interfere with the functioning of heaters and bulbs.


t246145Room Temperature and Cage Location

Room temperature will greatly affect you choice of heating equipment.  As most folks lower their heat at night, be sure to monitor temperatures at this time.  Oil-filled radiators may be a useful option, especially if you house your collection in a single room.


It’s important to have a detailed temperature profile of the rooms in which your terrariums and cages are located.  The Zoo Med Digital Infrared Thermometer  provides a simple, effective means of accomplishing this.  Pointing the thermometer at an area or surface will give an instant temperature readout, allowing you to identify the warmest and coolest places in the room. While exterior walls, floors and window areas are obvious cool spots, each home is different, so be sure to check carefully.  A simple terrarium re-location may save time, effort and money.


Terrarium ambient and basking temperatures should be carefully monitored, day and night; a huge array of herp-specific thermometers greatly simplifies this task.  Zoo Med’s Hygrotherm Humidity and Temperature Controller and other light and heater timers can help create healthful environments while cutting heating costs.


Iguana basking

Uploaded to Wikipedia Commons by Paul Kehrer

Insulating Terrariums and Cages

Insulation is not often used by herp and invertebrate keepers, but I urge you to look into the many possibilities.  I first discovered insulation during a power outage, and was surprised by the results I achieved.  I’ve since met several people who significantly cut their heating costs by lining terrarium and cages walls with various insulating materials.  Styrofoam, cork panels, polyethylene, polystyrene, foil fiberglass, bubble wrap and other home insulating materials  may all be put to good use.  Towels and blankets can be pressed into service during emergencies.


Wood and Masonite-sided cages will retain heat more effectively than glass, but all can be improved by the addition of insulation.  If such does not compromise your pet’s health, relocation to a smaller, more easily-heated enclosure might be worthwhile.


Bulbs and Heaters

Ceramic heat emitters, heat bulbs, under-tank heaters, red/black night bulbs and heat tapes are the most commonly-used heating devices.  Each provides heat in a different manner, although in certain respects there are overlaps as well.  The species you keep, your home’s temperature profile, and the characteristics of your pet’s enclosure will determine which method (or methods) should be used.  Please post below for specific information pertaining to your collection.


Slimy Salamander

Uploaded to Wikipedia Commons by Patrick Coin

Species Choice

If you live in an area that experiences extremely cold winters (or hot summers), you may wish to tailor your collection accordingly.  For example, axolotls, spotted and slimy salamanders, wood frogs and many other temperate zone amphibians are quite content at 55 F (fire salamanders that I attempted to chill down remained active at 40 F), but many do poorly when temperatures rise above 70 F.  Common musk turtles, northern five-lined skinks, Eastern garter snakes and other reptiles that range into cooler regions are also relatively easy to maintain during cold winters.  There’s certainly no shortage of interesting, cold-hearty species, and many are in need of study and captive breeding efforts.



A cooling off period during the winter can be beneficial for those species that experience dormancy in the wild, and is often essential to breeding success.  However, this step must not be undertaken lightly, and details vary by species.  Please post below for specific information on the animals in your collection.


Emergencies and Power Outages

Hand warmers and battery-operated aerators (for aquatic amphibians and fishes) should be available for use during power outages. I’ve not used a generator at home, but relied upon them several times during my years working at the Bronx Zoo…well-worth investigating.


Chilled reptiles, amphibians and invertebrates should be gradually warmed, not immediately placed at their optimal temperatures.  Heating pads are very handy in these situations.  Please post any questions or observations below.




Further Reading

The Best Infrared Temperature Gun for herp Terrariums


Hibernation/Brumation: Bearded Dragons and other Reptiles

What Do Leopard Geckos Eat? – An Ideal Diet Based on Zoo Research

High Yellow Morph

Uploaded to Wikipedia Commons by MKGeckos

What DO Leopard Geckos Eat?! The Leopard Gecko, Eublepharis macularius, makes a wonderful pet for novices and advanced hobbyists alike (even after many years as a professional zookeeper, I enjoy keeping them, and wrote a book about their care).  However, both sellers and buyers sometimes underestimate this delightful lizard’s needs, especially where feeding is concerned.  Contrary to popular belief, vitamin-powdered crickets and mealworms do not constitute a suitable diet!  If you wish your pet to live out its potential lifespan of 20-30 years in excellent health, you’ll need to provide it with as many different foods as possible.  Fortunately, a surprising array of insects can be purchased online and in stores.  Collecting and rearing your own insects is another excellent way to add to your gecko’s quality of life…and its great fun as well! Read More »

Providing Clean Water to Reptiles and Amphibians – The Nitrogen Cycle


Mexican Axolotl

Uploaded to Wikipedia Commons by ZeWrestler

Successful aquarists know the importance of monitoring the nitrogen cycle, and the lessons I learned while working for fish importers and sellers have served me well when caring for all manner of creatures.  When I began my career in zoos, I was surprised to find that reptile and amphibian keepers, while aware of the necessity for clean water, did not generally pay attention to understanding water chemistry and its effects on animal health.  That situation is much changed today, but professional and private herp keepers can still take some lessons from our aquarist friends. Awhile back, I helped establish an amphibian exhibit at the Maritime Aquarium in Norwalk, Ct.  I was not surprised when the aquarists there, despite lacking prior amphibian experience, excelled at their care and breeding.  Today we’ll look at how the nitrogen cycle functions and review some useful care techniques and products.


How Critical is Reptile and Amphibian Water Quality?

It’s important to understand that most amphibians, especially largely-aquatic species such as African Clawed Frogs and Mexican Axolotls, absorb water and dissolved chemicals over a much greater surface area than do fishes (scale-less fishes, such as eels, loaches and most catfishes, are similar to amphibians in this regard).  In fact, when we administer fish medications to aquatic amphibians, we always begin with a 50% or so dose…the amount recommended for fishes might kill or injure amphibians.


It follows that amphibians are often more sensitive to ammonia and other water-borne toxins than are fishes. My experience bears out the fact that ammonia poisoning is responsible for a great many sudden, unexplained amphibian pet deaths.  Reptiles are less susceptible to water quality problems than are amphibians, but certain species, such Tentacled Snakes and Soft-shelled and Fly River Turtles, seem sensitive to ammonia and pH levels.


Fly River Turtle

Uploadedto Wikipedia Commons by Faendalimas

What is the Nitrogen Cycle?

The nitrogen cycle can be summarized as the process by which nitrogen is converted to other organic compounds that are then utilized by plants and animals as food.  Nitrogen enters the water via dead animals and plants, decaying food, and animal feces and urates.  In herp enclosures, animal wastes are usually the primary sources of nitrogen.


Ammonia, the most toxic of the nitrogen-based compounds, may be ionized or un-ionized; it is most dangerous to aquatic animals in its un-ionized form. More of the water’s total ammonia becomes un-ionized as the temperature and pH increases.

Two types of aerobic (air-breathing) bacteria, which live on gravel, filter pads and other substrates exposed to oxygenated water, control the nitrogen cycle. Collectively, they are termed nitrogenous bacteria.


Nitrosomas bacteria convert ammonia to less-toxic compounds known as nitrites.  Nitrobacter bacteria convert the nitrites to nitrates.  Nitrates, the end product of the nitrogen cycle, are the least toxic of the nitrogenous compounds.


Managing the Nitrogen Cycle in Your Pet’s Home

Aquarists use the term “conditioning period” to describe the time that it takes for healthy populations of both types of nitrogenous bacteria to become established in a new tank.  This period varies in length, but usually falls in the range of 2-6 weeks.


Your aquarium’s conditioning period may be shortened by the addition of commercially-available live aerobic bacteria.  I’ve had good experience with Biozyme Freshwater Bacteria and Nutrafin Cycle.  Micro Lift Bacterial Water Balancer, specifically formulated for turtles, should also be considered.


You can also help the process along by introducing filter material from a well-conditioned tank and, where conditions permit, by using “live rock” and “live sand” (please post below for further info).  The frequent use of water quality test kits is essential. The pH level should be checked often as well, since the water may become acidic during the conditioning period.



Undergravel Filters

Although some of my younger readers will no doubt consider me a dinosaur for saying so, I still use and recommend undergravel filters in many situations.   They are simple to maintain, largely invisible to the eye, and essentially turn the entire substrate into a giant biological filter.  Where useful, power heads can be added to increase water follow though the gravel bed or to create a reverse-flow system (please see the article linked below).


Many public aquariums still maintain huge exhibits with undergravel filters alone.  At various zoos and in my own collection, I have used undergravel filters on large exhibits housing Tentacled Snakes, Northern Water Snakes, adult Snake-Necked Turtles, Largemouth Bass, and other creatures that are very hard on water quality and clarity.


I also favor fluidized bed filters, which are mounted outside the aquarium. They rely upon the same principles as do undergravel filters, and are especially useful where substrate is not used in the enclosure.




Further Reading

Using Undergravel Filters in Reptile and Amphibian Terrariums 


Using Bottled Aerobic Bacteria

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