That Reptile Blog » habitats

The Best Humidity Gauges for Reptile, Amphibian and Invert Habitats

Frank Indiviglio — Mon, 15 Apr 2013 15:06:45 +0000

Hello, Frank Indiviglio here. Like most lifelong animal keepers, I consider myself to be a fairly good judge of humidity levels in the home terrariums and zoo exhibits under my care. But when I began working in new buildings equipped with state-of-the-art hygrometers (humidity gauges), I quickly realized that I had much to learn. I was especially surprised to discover how widely humidity levels can vary within even a small enclosure, and how this can affect every facet of an animal’s life. The accurate, easy-to-use humidity gauges now available offer us the chance to provide better care to our charges and perhaps to uncover important new details about their lives.

Recent Innovations in Humidity Monitoring

Over the past several decades, hobbyists and zoos have greatly expanded the number of rare and delicate species that can be kept and bred in captivity. Many of these successes have been due to an increased understanding of the roles that UVB, temperature, diet and other such factors play in their lives.

Uploaded to Wikipedia Commons by Luc Viatour

Humidity levels have also been taken into account by serious animal owners, but this topic has been given less attention than others. This is partially because many reptiles, and some amphibians and invertebrates, can meet their needs by soaking in a water bowl or retreating to a moist shelter. But the real obstacle has been the unavailability of affordable hygrometers designed for use with animals. Happily, humidity gauges that fit just about every terrarium and budget are now available, and all are very simple to use (since I can do it!).

Areas of Special Concern

While all animals are to some degree affected by humidity levels, certain captives require closer monitoring than others. Humidity levels are crucial when most species are shedding/molting. Scorpions, centipedes, tarantulas, hermit crabs, mantids and other invertebrates easily become, as we say, “stuck in the molt” when humidity levels are too low. While we can sometimes assist them in this situation, most die.

Reptiles and amphibians usually survive dry molts, but problems ranging from fungal/bacterial infections beneath old skin to digit loss and retained eye caps may result. Poison frogs and other small, highly active amphibians, and those that remain in the open when resting, as do most treefrogs, are especially at risk from overly-dry conditions. Please see the articles below for further information on herp and invertebrate shedding concerns.

Humidity plays an important role in activity levels, cutaneous respiration, reproduction, immune system function, skin health and a wide variety of other processes. With so many amphibians in dire need of captive breeding these days, I believe it is critical that we begin to record our observations concerning humidity levels. Please consider using a hygrometer and relaying your thoughts by posting below; I’ll be sure to pass the information along, thanks.

The Zilla Humidity and Temperature Digital Gauge

This is my favorite gauge for average to large terrariums. The separate probes for temperature and humidity attach to the glass via suction cups, allowing for easy movement so that various areas of the terrarium (cave, basking site, etc.) can be monitored. I find the thin, 59 inch-long wires connected to the probes to be especially valuable. In smaller enclosures, the wires can be rolled up and secured with a twist-tie. The unit itself measures only 4 x 1 ½ inches, and is quite unobtrusive. It remains outside the terrarium, and features a built-in stand and a notch for wall mounting.

The Zilla Gauge monitors a humidity range of 10-99% and temperatures from -58 F to 158 F (if your pet requires conditions outside of those ranges, it likely belongs in a zoo!). “Comfort”, “Wet” and “Dry” messages are displayed at certain readings. While these are general in nature and will not apply to all species, many hobbyists find them useful. Temperatures can be displayed in either Fahrenheit or Celsius.

The unit also features an alarm, which can function as a reminder to check the terrarium or administer medications (if you sleep as lightly as I, it might also serve as an alarm clock!).

The Zoo Med Dual Humidity Gauge and Thermometer

Although marketed for use with hermit crabs, this small (3” x 1 ½”) gauge is ideal for small to moderately-sized terrariums housing most any species. Despite being quite inexpensive, it is accurate and stands up well to both damp and hot conditions.

The temperature and humidity levels are displayed side-by-side on brightly-colored, easy-to-read dials. “Dry”, “Optimum” and “Wet” ranges (for hermit crabs) are shown in different colors. The gauge attaches to glass with a sturdy Velcro strip.

Being colorful and simple to read, the Zoo Med Gauge is a great way to introduce youngsters to the concept of monitoring and recording environmental conditions. I plan to present several to my 5-year old nephew (shown here examining his “pet” mosquito larvae, much to his mom’s chagrin!) for use with his fire salamanders and domino roaches.

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

Day Gecko Care – Terrarium Set Up and the Best Supplies

Frank Indiviglio — Wed, 10 Apr 2013 16:25:19 +0000

Hello, Frank Indiviglio here. Gaily clad in brilliant, neon-hued colors, Day Geckos (Phelsuma spp.) are among the most desirable of all lizard pets, so here is a short article about Day Gecko care. Many are hardy, long-lived, and relatively simple to breed…but only if they are housed in a properly-designed habitat. Active and alert, these cautious animals fare poorly in bare enclosures, but are ideally suited for life in naturalistic, planted terrariums. The security provided by dense plantings and well-placed branches will put Day Geckos at ease and allow you to view a wide range of fascinating behaviors.

Setting up the Terrarium

Day Geckos are highly arboreal and must have climbing opportunities. “High-style” aquariums make fine homes. A pair or trio of Spotted, Yellow-Throated or other small species can be kept in a 15-20 gallon aquarium. A 30-55 gallon tank will accommodate the same number of Standing’s, Madagascar or Giant Day Geckos. Always opt for the largest terrarium possible.

Photo uploaded to Wikipedia Commons by Manuel Werner, Nürtingen, Germany

Day Geckos need spacious enclosures that mimic their natural habitat. Live plants such as Pothos and Philodendron will provide visual barriers between tank-mates and a sense of security. Rolled cork bark and hollow bamboo sections make ideal hideaways and perching sites, and should be arranged both horizontally and vertically.

Be sure to establish plenty of basking sites near heat and UVB bulbs, as dominant individuals may exclude others from these important areas.

The terrarium’s screen lid must be tightly secured with clamps.

Substrate

A mix of potting soil, cypress mulch and sphagnum moss is ideal.

Light

Day Geckos will not thrive without a source of UVB light (but some notable exceptions are known; please see article below). Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and that fatal overheating can occur very quickly.

Your geckos should be able to bask within 6-12 inches of a high-output UVB florescent bulb; the Zoo Med 10.0 Bulb, which I have used at the Bronx and Staten Island Zoos, has been shown to out-perform other florescent models. Mercury vapor and halogen bulbs broadcast UVB over greater distances, and emit beneficial UVA radiation as well. Be sure to provide shaded areas.

A daytime period of 12-14 hours should be established.

Heat

Ambient temperatures of 82-88 F, with a basking spot of 90-95 F, will suit most (please post below for information on individual species).

Incandescent spotlights may be used by day; ceramic heaters or red/black reptile “night bulbs” are useful after dark.

Provide your pets 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

Most Day Geckos are rainforest dwellers and do best in humid surroundings. Their terrarium should be misted at least twice daily. If your home is especially dry, consider using a small reptile fogger to raise the humidity levels in the terrarium (please see photo).

Companions

Males will fight savagely and cannot be housed together. Females are territorial, and must be watched carefully. Pairs, trios (1 male, 2 females) and youngsters may co-exist in large enclosures, but be sure to check dominant individuals do not prevent others from feeding and basking.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

The Best Terrarium Cleaning Products and Methods

Frank Indiviglio — Mon, 01 Apr 2013 16:01:31 +0000

Hello, Frank Indiviglio here. During a long career zoo career that found me working with animals ranging from ants to elephants, I’ve had many occasions to review veterinary and pathology reports. In doing so, I’ve come to understand that zoonotic diseases – those that can pass from animals to people – are a potential concern in the keeping of any pet. Most people associate Salmonella, the best known zoonotic, with reptiles, but nearly any animal, including dogs, cats and birds, may harbor this bacterium. Fortunately, Salmonella and other infections can be avoided by following a few relatively simple rules.

Note: This article is not meant to replace a doctor’s advice, nor is it intended to discourage pet ownership. By observing a few simple precautions, the most commonly-encountered problems can be effectively managed. Please post your questions and concerns below, and be sure to consult your doctor or veterinarian for specific information concerning disease prevention and treatment.

What Are the Risks?

Uploaded to Wikipedia by Jens Raschendorf.

If we are to safely enjoy our pets, it is important that we become aware of the concerns while maintaining a reasonable perspective.

For example, while it is true that Salmonella bacteria are likely present in all reptile and amphibian digestive tracts, merely handling an animal that carries Salmonella will not cause an infection. Salmonella bacteria are harmful to people only if ingested. Consider also that dogs may potentially carry at least 17 harmful microorganisms, yet the vast majority of dog owners are never troubled by health problems. Similarly, the same can be said of reptile owners, zookeepers and herpetologists – Salmonella infections are not typical.

Please see this article for information concerning Mycobacteria.

How Infections Are Contracted

Understanding how bacteria are transferred from animals to people is the key to avoiding Salmonella infections. Salmonella bacteria are shed in the feces and can live on counters, tools, food bowls, animal skin and other surfaces for several days.

Reptile skin, water bowls, terrarium substrates and other surfaces may harbor bacteria that have been shed in feces. People can become infected and/or spread the bacteria to others if they handle a reptile (or its cage, etc.) and then eat or touch surfaces that come in contact with food before washing properly.

Basic Rules

Always wash your hands with hot, soapy water after handling animals and tools used to service aquariums or terrariums, and after being in an area where animals are allowed to roam free.

Stop working with your pets if you receive a cut or break in the skin. Exposing a wound to terrarium or aquarium water after applying an antibiotic will negate the value of the medicine. Seek a doctor’s advice.

Wear gloves or use a substrate scooper when cleaning animal enclosures. Disposable gloves, available in pharmacies, are fine for most terrariums. Coralife Aqua Gloves, which reach to the elbow, are very useful for aquarium work. Wear goggles if splashing water is a concern.

Uploaded to Wikipedia Commons by , LiquidGhoul.

Reptiles should not be allowed into kitchens, dining rooms or other areas where food is prepared or eaten. Bathroom sinks and tubs, and areas where infants are bathed, should also be off-limits.

Reptiles should not be allowed to roam about the home (this presents a fire hazard as well). If it is necessary to keep a reptile un-caged, it should be confined to an easily-cleaned room from which human food and at-risk individuals (small children and elderly or immune-compromised individuals) are excluded.

Terrariums, aquariums, food bowls and other animal-related items should not be cleaned in kitchen or bathroom sinks. A plastic tub should be used if a basement or “animal-only” sink is not available. Rinse water and fecal material should be disposed of in a toilet, not a sink or tub. Clean accidental spills with a product that contains bleach.

Never start a siphon by sucking on its end with your mouth. Always fill it with water to create suction or use a hand-operated siphon starter.

Do not drink, eat or smoke while working with animals. Never kiss your pet or feed it from bowls used for your own meals.

The Center for Disease Control guidelinescontain additional precautions. Please review them carefully.

Cleaning Terrariums, Aquariums and Related Items

Reptile enclosures, food bowls and the like should be cleaned with Nolvasan, a reptile-safe commercial cleaner, or a bleach solution (1 cup bleach per gallon of water). Zoo Med Wipe Out Terrarium Cleaner kills a wide range of commonly-encountered bacteria, including Salmonella and Pseudomonas.

Uploaded to Wikipedia Commons by Pedro Reina.

Amphibians, invertebrates and fishes are especially sensitive to chemicals. Their terrariums and aquariums should be cleaned with fish-safe products or with the bleach solution described above.

Cleaning implements should be soaked in any of the aforementioned cleaners before being re-used. Be sure to remove feces and other organic material before soaking. Rinse the tools well after removal from the soak solution. Immersion in water containing an instant de-chlorinator is recommended for hard-to-clean items (i.e. siphon and filter tubes) that are to be used with fishes or amphibians.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Supplies for Red Eared Sliders and Similar Turtles

thatpetblog — Thu, 28 Mar 2013 17:16:25 +0000

Hello, Frank Indiviglio here. Tempted to buy that tiny green turtle being offered for a mere dollar or two? While Red-Eared Sliders (Trachemys scripta elegans) can make an interesting and responsive pets, their care is far more complicated (and expensive!) than most new owners expect. In perhaps no other animal is the distinction between initial price and long term cost of care so great. Furthermore, the care guidelines offered by many sellers are often overly-simplified and inaccurate. Following is a list of everything you’ll need to provide a proper home for Red Eared Sliders and other species with similar lifestyles (i.e. Map, Painted and Side-Necked Turtles, Cooters), along with notes concerning each item. An in-depth article about Slider care and natural history is posted here.

Do Not Buy Hatchlings!

Although newly-hatched Sliders are still offered for sale, usually at fairs, carnivals and street stalls, it is illegal to sell them (or any turtle less than 4 inches in length) in the USA, and has been since 1975. The law was enacted by the Food and Drug Administration in response to Salmonella outbreaks linked to hatchlings. For further information on the Salmonella- turtle connection, please see this article.

Because Sliders grow much faster than most owners expect, turtle rescue organizations are swamped with unwanted pets. Please consider adopting rather than purchasing a turtle; please post below if you need adoption assistance.

The Aquarium

Sliders grow rapidly, and may attain full size within 2-4 years. Females reach 8-12 inches in both length and width (think large dinner plate) while males generally top out at 6 inches. Being quite active, an adult female will require a 55-75 gallon aquarium at minimum; a male might get by in a 30 gallon, but more room (for either sex) is preferable.

Zoo Med’s Turtle Tub makes an excellent home for large and small Sliders.

Children’s wading pools or koi ponds are often easier to manage than aquariums, especially if you have more than one turtle. Plastic storage bins can easily be modified into low-cost turtle homes. Please post below for further information.

Basking Site

Red-Eared Sliders need a non-abrasive surface on which to rest and dry off. The basking site should be located beneath a heat and UVB bulb, so that your turtle can attain its ideal body temperature and manufacture Vitamin D3 within the skin (see Heat and UVB Bulbs, below).

I prefer basking sites that are suspended at the water’s surface, as these do not take up valuable swimming space. Zoo Med’s Turtle Dock features a sloping ramp and is available in several sizes.

Larger individuals may partially submerge platforms that attach to aquarium glass, and hence will not be able to completely dry-off while basking. The Penn Plax Turtle Pier has a gravel reservoir to offset the weight of larger turtles, and also provides a sub-surface hiding and resting spot.

Cork bark also works well, especially if wedged between the aquarium’s sides.

Filter

You can do without a filter if your turtle lives in an easily-emptied plastic bin. However, filtration is essential if you maintain these messy feeders in an aquarium. A wide variety of submersible and canister filters, designed specifically for use with turtles, are now available. Please see this article to read about my favorite types. A siphon will simplify waste removal and partial water changes.

Feeding Enclosure

Although not essential, a separate feeding enclosure, such as a plastic sweater box, will ease the filter’s job and limit the frequency of water changes. Please see this article for more on maintaining water quality.

Water Heater

Use a “turtle proof” submersible heater to maintain your Slider’s water at 76-82 F and a reptile thermometer to monitor water and air temperature.

Heat Bulb

An incandescent “spot type” bulb should be employed to heat the basking site to 85-90 F. The basking light will usually warm the rest of the enclosure sufficiently (78-82 F). If additional heat is needed, red/black night bulbs or ceramic heater-emitters may be added.

Ultra Violet-B (UVB) Bulb

Red Eared Sliders need daily exposure to UVB light. Your turtle should be able to bask within 6-12 inches of a high-output UVB florescent bulb, such as the Zoo Med 10.0 . Mercury vapor and halogen bulbs broadcast UVB over greater distances, and emit beneficial UVA radiation as well.

Natural sunlight is ideal, but be aware that UVB rays do not penetrate glass or plastic, and that fatal overheating can occur quickly.

Substrate

Sliders are best kept in bare-bottomed aquariums; gravel traps dirt, complicates cleaning, and may be swallowed.

Food

Young Red-Eared Sliders are largely carnivorous, but increasingly consume plants as they mature. By adulthood, vegetation forms the bulk of the diet.

Reptomin Food Sticks and trout chow provide excellent nutrition; either can serve as up to 50% of the diet.

Dandelion, kale, mustard and collard greens, romaine, endive and aquarium plants such as Elodea, Anachris, Watersprite and Duckweed should be offered.

Whole freshwater fishes such as minnows and shiners are the best source of calcium (and other valuable nutrients) for turtles. Offer fish at least once weekly, but use goldfishes sparingly (please see this article).

Other important food items that should be a regular part of the diet include earthworms, canned snails and fresh or freeze-dried shrimp and krill. Crickets, mealworms, waxworms and other insects may be offered on occasion.

Although best known to most folks as pets, Sliders also have a fascinating natural history. Please see the articles below to read about their lives in the wild.

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

Collared Lizard Captive Care and Natural History

Frank Indiviglio — Fri, 08 Feb 2013 15:37:34 +0000

Hello, Frank Indiviglio here. The 8-14 inch-long Collared Lizard, Crotaphytus collaris, is one of North America’s most colorful reptiles. Alert and active by day, Collared Lizards housed in planted desert terrariums make for stunning displays. They also possess distinct personalities, accept gentle handling, and, being relatively easy to breed, are now available in a variety of interesting color phases and patterns. The following information can also be applied to the related but less-commonly kept Leopard Lizard, Gambelia spp.

Taxonomy, Range, and Habitat

Nine species of Collared Lizard have been described. In the pet trade, the name “Collared Lizard” is most frequently applied to Crotaphytus collaris. Five subspecies of Crotaphytus collaris range from the central and southwestern USA to central Mexico. The Eastern Collared Lizard, Crotaphytus c. collaris, is the subspecies most commonly kept in captivity. Its range extends from southern Missouri through northern Arkansas and southwest to central Texas. Different Collared Lizard species hybridize in captivity and the wild.

The related Leopard Lizards (3 species, please see photo) have been reassigned to the genus Gambelia.

Collared Lizards are usually found in rocky deserts, overgrown thorn-scrub and other arid habitats.

Behavior

Wild-caught lizards are difficult to acclimate, but captive-born individuals usually take handing in stride. If threatened, however, they will not hesitate to bite. Collared Lizards can rise up on their hind legs when fleeing from danger, evoking the image of a tiny, colorful T-Rex. They are extremely fast, and may quickly make use of escape opportunities presented when their enclosures are being serviced.

Collared Lizards are very active…foraging, territorial displays, moving from hot to cooler areas, and digging occupies much of their time. Possibly in response to an “internal clock”, they sometimes refuse food during the winter, even if kept warm (please write in for further information).

Housing

Setting up the Terrarium

The Collared Lizard’s active lifestyle demands a great deal of space. Youngsters can be reared in 20 gallon aquariums, while a single adult is best kept in a 30 gallon tank (a properly designed 20 gallon can work, but more space is preferable). A 55 gallon terrarium will accommodate a pair or trio.

Due to the high basking temperatures required, large enclosures are necessary if a thermal gradient (areas of different temperatures) is to be established. Thermal gradients allow lizards to regulate their body temperature by moving from hot to cooler areas. This behavior, critical to their health, is not possible in small cages.

Collared Lizards are ground-dwelling animals that use rocks as basking sites and perches from which to watch for danger. Rocks should always be placed on the terrarium’s floor so that lizards cannot tunnel beneath them and be crushed in the process. Stacked rocks should be secured to the glass or one another with silicone if tipping is a concern.

In addition to adding greatly to your terrarium’s aesthetic value, live plants will offer a sense of security and provide sight barriers that help to limit aggression. Useful types include Climbing and Lace Aloes, Oxtongue and Snake Plants.

As air flow is especially important for animals native to arid habitats, your terrarium should be equipped with a screen top.

Substrate

A sand/small rock mix is the most natural substrate for Collard Lizards. Although impactions due to swallowed sand are rare, it is best to provide food in large bowls so that sand ingestion is limited. Rocks small enough to be swallowed should be avoided. Hatchlings are clumsy hunters, and tend to swallow a good deal of sand. Newspapers, paper towels or washable cage liners should be used until their skills improve.

Light, Heat and Humidity

Collared Lizards will not thrive if denied daily exposure to high levels of UVB light. Natural sunlight is best, but be aware that glass and plastic filter out UVB rays, and that fatal overheating can occur very quickly. If you use a florescent bulb, choose one designed for desert-dwelling lizards (i.e. the Zoo Med 10.0 Bulb) and position the basking site within 6-12 inches of it.

Mercury vapor and halogen bulbs broadcast UVB over greater distances, and also emit beneficial UVA radiation. Be sure to provide shaded areas as well.

Collared Lizards require a basking site temperature of 95-100 F, but must be able to move into cooler areas (78-85 F) as well. Temperatures can dip into the high 70’s at night. Incandescent bulbs may be used by day; ceramic heaters or red/black reptile “night bulbs” are useful after dark.

Humidity should be kept low, and the substrate must be dry at all times.

Companions

Females and youngsters usually co-exist, but groups must be watched as dominant individuals may prevent others from feeding and basking. Males will fight viciously and cannot be kept together.

Feeding

These voracious predators are largely insectivorous, but also take small lizards and snakes on occasion in the wild. Their calcium requirements appear to be quite high. Pink mice are a good calcium source, but should not be offered more than once each 7-10 days. Rodents with fur should be avoided.

Roaches, waxworms, crickets, butterworms, silkworms, calci-worms, super mealworms, hornworms, sow bugs and other commercially-available invertebrates should form the bulk of the diet. Crickets and mealworms alone are not sufficient. Insects should themselves be provided with a nutritious diet for 1-3 days before being offered to your pets.

In order to increase dietary variety, offer your lizards canned grasshoppers, snails and silkworms via tongs. Wild-caught insects, as long as you can recognize dangerous species and avoid pesticide-contaminated areas, should also be offered; moths, beetles, grasshoppers and many others will be readily accepted. Please see this article for additional information on feeding insectivorous lizards.

Wild Collared Lizards consume some vegetation, but captives often reject non-living foods. Adding live insects to a bowl of kale, dandelion and other produce may encourage acceptance.

Food (excepting pinkies) should be powdered with Tetra ReptoCal, Zoo Med ReptiCalcium or a similar product. Vitamin/mineral supplements (i.e. ReptiVite with D3) should be used 2-3 times weekly.

Adults can be offered food 5-7 times weekly, while juveniles should be fed on a daily basis.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Monitor Lizard Care, Natural History and Behavior – An Overview

Frank Indiviglio — Thu, 24 Jan 2013 17:04:03 +0000

Hello, Frank Indiviglio here. I’ve had the good fortune of caring for 15-20 monitor species during my zoo career. From the diminutive Storr’s to the massive Water, Lace, Crocodile and Komodo Monitors, all have instilled in me the feeling that they were, somehow, “more complicated” than other reptiles. Indeed, recent studies have confirmed that they are, among lizards, highly advanced. While some are too large for the average household, several moderately-sized and even dwarf varieties are being bred by hobbyists, and all make fascinating and responsive captives.

The following information can be applied to the care of Savannah, Black Tree, Nile, Merten’s and most other monitors. However, details vary; please post below for information on individual species, and be sure to add your own thoughts and observations on monitor lizard care.

Natural History

Seventy-three monitor species (Family Varanidae) range across Asia, Africa and Australia. Nile Monitors (Varanus niloticus), introduced to south Florida, are a major environmental concern there. Lace Monitors (V. varius) and other large speciesare usually the dominant predators in their habitats. While most dwell in warm regions, Desert Monitor (V. griseus) populations in Kazakhstan are adapted to Vermont-type winters.

The 8 inch-long Short-Tailed Monitor (V. brevicauda), is the smallest member of the group. The Komodo Dragon (V. komodoensis), the world’s largest lizard, occasionally tops 10 feet in length.

Monitors take prey ranging in size from termites to deer. The recently-discovered Sierra Madre Forest Monitor (V. bitatawa) and the Philippine Monitor (V. olivaceus) are unique in consuming fruit, while the Komodo Dragon has attacked and killed people.

In 2005, it was discovered that several species produce venom that affects their prey’s blood pressure and clotting ability.

Five new species, one topping 6 feet in length, have been described in the past several years (please see articles below).

Behavior

Monitors are ever-alert, and easily startled by noises and sudden movements. They vary greatly in personality – some become quite docile, while others remain wary of people. All are very responsive, and quickly learn to anticipate regular feeding times.

Crocodile and Water Monitors (V. salvadorii and V. salvator), and other large species, can be dangerous and are not suitable for most private collections. Adult Water Monitors are, pound-for-pound, one of the strongest animals I’ve ever restrained (I was the Bronx Zoo’s head mammal keeper for a time, and so thought I could handle most anything!). All monitors can inflict severe bites and scratches. The mouth and tail (which is whipped about in self-defense), should never be allowed near one’s face. Operating policies in most zoos require that 2 experienced keepers be present when large monitor exhibits are entered.

New monitor facts frequently come to light. Recently, a Black Tree Monitor was observed using its front foot to extract an insect from a crevice; this behavior has not been documented in any other lizard.

Housing

The Enclosure

Hatchlings and small species, such as the 14-inch-long Storr’s Monitor (V. storri), may be housed in 30-55 gallon aquariums.

Merten’s Monitors (V. mertensi) and others in the 3-4 foot range are best kept in homemade cages measuring at least 4x4x4 feet. Height is an important consideration for arboreal species such as Black Tree Monitor (V. beccarii). Savannah Monitors (V. exanthematicus) and others that approach 5 feet in length need correspondingly larger quarters; modified cattle troughs are a useful option.

The 6-7 foot-long Nile, Lace, Crocodile and Water Monitors require room-sized enclosures with drainable pools.

Predator-proof outdoor cages are the ultimate in “luxury accommodations” (some folks use modified bird aviaries). If a safe, escape-proof room is available, out-of-cage exercise time can make a real difference in your lizard’s quality of life.

Furnishings

Stout branches, wooden shelves and secure hide boxes should be arranged according to each species’ individual needs (please post questions below). A water bowl large enough for bathing is essential; the aquatic Merten’s Monitor should be provided with a large swimming area.

Substrate

Sand is suitable for Desert Monitors and others native to arid habitats, while cypress mulch works well for forest dwellers such as Green Tree Monitors (V. prasinus). I’ve found Crocodile Monitors prone to foot abrasions when kept on concrete, and have since used rubber mats or rubber-coated floors for all large species.

Although impactions due to swallowed substrate are rare, food should be provided in large bowls or via tongs, so that ingestion is limited.

Light

Monitors need daily exposure to UVB light. Use a high-output bulb, such as the Zoo Med 10.0, and position the basking site within 6-12 inches of it. Mercury vapor and halogen bulbs broadcast UVB over greater distances and emit beneficial UVA radiation as well.

Heat

Temperature should be maintained at a range of 79-85 F for most species. Incandescent bulbs should be used to create a basking site of 90-95 F. Ceramic heaters or red/black reptile “night bulbs” may be employed to provide heat after dark. Under-tank heaters may be used to create a warm basking surface.

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.

Humidity

Storr’s and Savanna Monitors, and other desert/grassland adapted species, develop health problems in damp enclosures, while rainforest dwellers such as Blue Tree Monitors (V. macraei) need access to humid and dry areas.

Companions

Males will fight savagely and cannot be housed together, and females sometimes battle for dominance. Juveniles may get along, but they must be watched carefully.

Feeding

Strict attention to diet is essential if you are to succeed with monitors. Nutritional deficiencies can develop quickly, and are difficult to treat. High calcium intake and exposure to UVB light is especially important for young animals.

Small, largely insectivorous species (i.e. Blue and Green Tree Monitors) need a highly-varied diet comprised of roaches, crickets, butterworms, hornworms, super mealworms, wild-caught insects and other invertebrates; pink mice can be offered 1-2 times weekly. Canned snails and grasshoppers, and hard-boiled eggs, can be used to provide variety.

Nile Monitors and similar species fare well on mice and rats alone; whole freshwater fishes are an excellent rodent-alternative for Water and Merten’s Monitors.

Food (other than vertebrates) should be powdered with Tetra ReptoCal or Zoo Med ReptiCalcium. Vitamin/mineral supplements such as Reptivite should be used 2-3 times weekly.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

The Best Filters for Axolotls, Clawed Frogs, Newts and Other Amphibians

Frank Indiviglio — Thu, 17 Jan 2013 21:02:41 +0000

Hello, Frank Indiviglio here. With their highly-permeable skins, amphibians absorb ammonia and other pollutants over a greater surface area than do fishes. Surinam Toads, Axolotls, tadpoles and other aquatic amphibians are most at risk from poor water quality, but even terrestrial species such as toads and Fire Salamanders can quickly succumb to water-borne toxins while soaking in terrarium pools. Keeping their water clean, both visibly and chemically, can be quite a challenge.

General Considerations

Natural History

Your pet’s natural history will determine the type of filter that should be used. For example, newts and Dwarf Clawed Frogs will be stressed by fast currents, Hellbenders are extra-sensitive to water quality, many species are prone to bacterial attack in highly-oxygenated waters, and so on. Please post below if you need help in selecting a filter.

Types of Filtration

Biological filtration, wherein aerobic bacteria convert ammonia to less harmful compounds (nitrites and nitrates), is the most important of the three basic filtration processes. Ammonia enters the water via dead animals and plants, uneaten food and the occupants’ waste products. The organisms involved in the process, Nitrosomas and Nitrobacter bacteria, live on substrates that are bathed with oxygenated water (i.e. gravel, filter pads).

Aerobic bacteria starter cultures may be purchased (i.e. Nutrafin Cycle) or obtained from the filter materials in a well-established tank. Always leave a bit of old material in your filter when changing carbon or filter pads, so that aerobic bacteria will seed the new filter medium.

Suspended solids and chemicals are removed from the aquarium through mechanical and chemical filtration.

Live Plants

Aquatic plants will assist filters in maintaining water quality and amphibian health. Pothos, Peace Lilies and other terrestrial plants that adapt to watery environments can also be used. Please do not discount the effects of live plants…I and many others can attest that they can make a real difference.

Water Changes

The use of a filter does not eliminate the need for regular water changes, as ammonia will accumulate even in well-filtered enclosures.

Undergravel Filters

Yes, they are largely ignored today, but I believe this to be serious error. I have used undergravel filters to successfully keep a wide range of delicate amphibians, and have included them in several of the large zoo exhibits I’ve designed.

Undergravel filters transform the entire aquarium substrate into a biological filter. Water drawn through the gravel nourishes beneficial aerobic bacteria and inhibits the growth of harmful anaerobic species. The return tubes can be cut so that even a small pool in a terrarium can be filtered.

Undergravel filters are especially useful when rearing eggs, larvae and tadpoles, because they will not injure animals with suction and strong currents. Please see this article for detailed information on their use.

Corner or Box Filters

These “old-fashioned” inside-the-tank filters are actually quite effective if powered by sufficient airflow. I maintain a number of tanks using corner filters alone. In addition to providing mechanical and chemical filtration, these filters support aerobic bacteria that assist in ammonia detoxification.

Ideally, a corner filter should have low and high intake ports, so that water will be pulled from the very bottom of the tank and at a slightly higher level I recommend the Lee Triple Flow; most others lack low intakes. As a corner filters outflow is directed upwards, strong currents that might disturb eggs, larvae or weak-swimmers are avoided.

Corner filters can be easily hidden with plants. Live Java Moss is ideal for this purpose.

Sponge Filters

Sponge filters provide mechanical and biological filtration, and are ideal for use with amphibian eggs and larvae, and delicate specimens. They work well with African Clawed Frog tadpoles and other filter-feeders, as minute food particles are not rapidly removed from the water. This is also a consideration when salamander larvae are being reared, as many feed upon Daphnia, brine shrimp and other tiny creatures that may be pulled into more powerful filters.

The filter should be periodically cleaned by rinsing it in cool water (hot water will kill beneficial bacteria). Chemical filtration is not provided, so regular water changes are especially important.

Zoo Med Turtle Clean Canister Filter

This powerful filter is designed with turtle-keepers in mind (please see this article for information on filtering turtle tanks). In common with fish canister filters, the Turtle Clean has ample chambers for carbon, filter pads and aerobic bacteria colonies, and is simple to clean. It is placed next to (not below) the tank, and can be used to create a waterfall effect.

Despite its size and power, the Turtle Clean Filter can operate in as little as 2 inches of water, rendering it ideal for use in terrarium ponds or in shoreline-type setups housing American Bullfrogs, Leopard Frogs and similar species.

A powerful motor enables this filter to handle the copious wastes produced by Mudpuppies, Sirens, Amphiumas, Surinam Toads and other large amphibians. However, water can also be returned to the aquarium via a spray bar, so that newts and other small amphibians can also be maintained.

Supreme Ovation Submersible Power Jet Filter

The Supreme Ovation is first submersible, combined pump and filter to be marketed in the USA; my original unit operated continuously, under great strain, for approximately 20 years!

The four models currently available are extremely powerful, but are equipped with a movable outlet tube and a spray bar so that strong currents can be avoided. The largest (Model 1000) circulates 265 gallons per minute, yet is compact and easy to service.

Other Filters

Nearly all filters designed for use with tropical fishes can be of use to amphibian keepers. Although certain modifications may be required, many are worth investigating as a great deal of research has gone into their development.

You can check out 50+ aquarium filters options here. Please be sure to post your ideas, experiences and questions below.

Please also post your questions and comments here…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Further Reading

Undergravel Filters in Terrariums and Aquariums

Ammonia Toxicity in Amphibians

Amphibian Lab Filtration Techniques

Filtering Turtle Tanks

NutraFin Cycle: Bacteria in a bottle

Axolotls image referenced from wikipedia and originally posted by ZeWrestler
Tadpoles image referenced from wikipedia and originally posted by MarJon

Post from: That Reptile Blog

The Best Filters for Axolotls, Clawed Frogs, Newts and Other Amphibians

The post The Best Filters for Axolotls, Clawed Frogs, Newts and Other Amphibians appeared first on That Reptile Blog.

Round Island Boa Reintroduction – Back in Wild after a 150-Year Absence

Frank Indiviglio — Wed, 12 Dec 2012 15:11:36 +0000

Hello, Frank Indiviglio here. Mauritius, an island nation off the coast of southeast Africa, is best known to naturalists as the site of the Dodo Bird’s extinction (Mauritius also is, in a sense, the reason I was hired by the Bronx Zoo and spared life as a lawyer – see article below for the story!). Herp enthusiasts, however, know it as the habitat of several unique reptiles, all of which are now very rare or extinct. But we can delight in some news just released by the Durrell Wildlife Trust - a new population of the Round Island or Keel-scaled Boas, Casarea dussumieri, will soon be established in the wild. This unusual snake disappeared from nearly all of its range in the 1860’s, and its return is the culmination of 40 years’ worth of captive breeding and habitat restoration efforts.

Status and Conservation

The Round Island Boa is now confined to Round Island, a tiny speck of habitat where perhaps 500-1,000 individuals survive. A single wild population and limited number of captives place it at continued risk of extinction. The new population to be established on another Mauritian island (where the snake formerly lived) is a vital step towards ensuring the species’ survival.

The Durrell Wildlife Trust became the first institution to breed the Round Island Boa, and maintains most of the captive population. Founded by legendary conservationist and author Gerard Durrell, this unique organization focuses on critically endangered animals and plants, especially those overshadowed by pandas, rhinos and other “charismatic mega-vertebrates”. The Trust was the first to breed the Giant Jumping Rat, Lesser Antilles Iguana, Flat-tailed Tortoise and scores of others (please see article below).

The Reintroduction

The island selected for the new Round Island Boa population has been cleared of the introduced black rats, goats and rabbits that previously destroyed the habitat and prey base. The snake’s primary food, the Telfair’s Skink (Leiolopisma telfairi), was released on the island in 2007 and is now well-established. Like other Mauritian reptiles, Telfair’s Skink has been eliminated from much of its range, but survives on Round Island and at the Durrell Wildlife Trust.

The boas to be reintroduced were collected from Round Island, and will first be monitored to assure that they are genetically diverse and disease-free.

Round Island Boa Natural History

Although originally placed in the genus Boa, this species differs so greatly from seemingly-related snakes that is now classified in its own genus and family (Bolyeridae). The family’s only other member, the Round Island Burrowing Boa (Bolyeria multacarinata), has not been seen since 1975 and is presumed extinct.

The Round Island Boa is oviparous, and changes in color from bright orange to grayish-brown as it matures. There are some indications that females remain with their eggs for a time. Unique scalation lends the alternative common name of Keel-scaled Boa. Juveniles and some adults (especially females) appear to be largely arboreal.

The Round Island Boa’s preferred habitat – forest and palm-dotted savannah – has been largely reduced to brushy scrub by agricultural development, introduced rabbits and goats. Rat predation on young snakes and skinks has contributed to the species’ drastic decline.

What’s Next?

The reintroduced population will be closely monitored by Durrell Wildlife Trust staffers and other conservation organizations. In addition to establishing a new population, the project may serve as a template for future herp recovery efforts. I’ll post updates as they become available.

There are many other success stories, as well as failures. Please post your own thoughts and examples below so that I can share them with readers and researchers. Thanks.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Land Hermit Crabs and Coconut Crabs (the world’s largest) as Pets

Frank Indiviglio — Wed, 07 Nov 2012 14:45:59 +0000

Hello, Frank Indiviglio here. People are often surprised to learn that Land or Terrestrial Hermit Crabs engage in complex social behaviors, are capable of communicating via “chirps” and, with proper care, may live for over 20 years. I’ve had the pleasure of working with them at home, in zoos and the wild, and have even kept the massive, awe-inspiring Coconut Crab. Please read on to learn about their care and natural history, and be sure to post your own thoughts and experiences.

Natural History

The Purple-Pincher or Caribbean Hermit Crab (Coenobita clypeatus) is the most common pet trade species. It ranges throughout the Caribbean, reaching as far north as Florida and Bermuda.

Some populations live at altitudes of over 3,000 feet, but females return to the sea, usually in one massive migration, to spawn. The larvae, or zoea, float about with plankton for 2 months, after which they take up life on land.

Land Hermit Crabs carry about the discarded shells of other creatures as shelters, and must find larger shells as they grow. Recently it was discovered that they will line up in size order behind an empty shell – as the first crab (the largest) moves into its new home, others in line will “trade up” for the shell of the crab immediately in front of them! Please see the article below for details.

Ecuadorian Hermit Crabs (Coenobita compressus) and several Asian species also appear in the pet trade. The Coconut Crab (Birgus latro) is sometimes kept within its native range.

Behavior

Land Hermit Crabs are nocturnal, but pets often emerge to feed by day. When established in a properly-designed terrarium, they will be quite active and exhibit many interesting behaviors.

Handling is stressful to Hermit Crabs, including long-term pets. They can be grasped by the back of the shell, but often can reach this area with their claw. Large individuals can administer a painful pinch, and I’d bet that the Coconut Crab can break fingers!

Housing

Setting up the Terrarium

A 10 gallon aquarium will accommodate 4-5 small crabs. Large, naturalistic terrariums will allow the crabs to exhibit a wider range of behaviors than will small, bare enclosures.

Driftwood, cholla wood, reptile caves, up-ended clay flower pots and similar furnishings will add greatly to your crabs’ quality of life. Empty shells should always be available.

A molting tank should be set up if you keep more than one crab. Land Hermit Crabs are soft and defenseless after molting, and will be eaten by their former friends. Check daily for signs of an impending molt – digging, remaining below ground and listlessness are typical. Molting crabs should be isolated (please write in for information).

Substrate

A mix of calcium sand and coconut husk makes an ideal substrate. The substrate should be at least 6 inches deep and mixed with enough water so that is just sticks together when squeezed.

Light

Red/black reptile night bulbs will allow you to watch your crabs after dark. A 12-hour day/12 -hour night cycle is ideal.

Heat

A temperature range of 75-82 F should be maintained. These tropical creatures will not survive long term exposure to temperatures below 72 F.

Incandescent bulbs or red/black reptile night bulbs can be used to heat the terrarium. Ceramic reptile heaters are useful at night. Reptile heat pads can be used to warm the substrate, but these do little to heat the air. All of the above will dry out the substrate, so it is important to monitor the humidity.

Humidity

Land Hermit Crabs possess unique gills that enable them to breathe air. A humidity level of 70-80% is vital to survival, as the gills must be kept moist in order to function. A simple humidity meter should be used. Humidity can be increased by misting, adding water to the substrate and partially covering the terrarium’s lid with plastic.

Companions

Land Hermit Crabs are social animals, but dominant individuals may prevent others from feeding properly. Crabs that are molting must be isolated or they will be attacked (please see above). A variety of empty shells must be available, or fighting and “evictions” will ensue.

Feeding

Wild Hermit Crabs eat just about everything – animal, vegetable and mineral – that they encounter. Captives will not thrive without a varied, high-calcium diet.

Commercial Hermit Crab pellets may be used as a portion of the diet. The following foods should be included regularly: fresh shrimp and fish, fruits and vegetables (carrot may help to maintain coloration), hard-boiled egg, nuts, seeds, dry seaweed (sold as Nori), oatmeal, fish flakes, canned crickets, and freeze-dried fish foods (krill, plankton, brine shrimp, etc.). They also relish decaying wood and leaf litter; these should be collected from pesticide-free areas.

Cuttlebone bits and reptile calcium powder should be mixed into your crabs’ food.

Often overlooked is their need for a bowl of marine water; marine aquarium salt mixes, not table salt, should be used. Soaking in this water will provide the crabs with essential minerals not present in their food. Fresh de-chlorinated water should also be available. Bowls should be filled to half the height of the smallest crab and be easily-exited, as Land Hermit Crabs drown easily.

A wide variety of specialty cages, supplies and foods are now available. Please post any questions or comments you may have regarding their use.

The Coconut or Robber Crab (Birgus latro)

With a 16 inch body supported by legs spanning 3 feet, this impressive beast (described as “monstrous” by Charles Darwin!) is the world’s largest land-dwelling arthropod. I first saw them at the Cincinnati Zoo Insectarium in the early 1980’s, and was instantly hooked. After a prolonged search, I obtained 2 adults for an exhibit at the Bronx Zoo. Unfortunately, they did not fare very well, and this seems to be a common experience (wild individuals may attain age 40+). Losses are especially high during the month-long molt, which is spent underground.

The Coconut Crab ranges throughout the Indian and Western Pacific Oceans. A co-worker of mine found them raiding his garbage cans on Guam; his experiences with refuse-feeding coatis and coyotes elsewhere in no way prepared him for that!

Coconuts may be their best-known food, but form only a small portion of the diet. Generally, the crabs pinch nuts from coconut palms, and then feast on the broken remains below. A crab may also pull back the husk from an unbroken coconut and then pierce the soft “eye” with one of its pointed legs. The rest of the diet is as varied as that of their smaller relatives.

Coconut Crabs are declining in portions of their range. Threatened by food trade collection and predation by introduced rats, ants, pigs and monkeys, they have been extirpated from Australia and Madagascar.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio

Amphibian Declines – Pollution Worsens Disease and Parasite Attacks

Frank Indiviglio — Mon, 22 Oct 2012 16:00:13 +0000

Hello, Frank Indiviglio here. In 1990, the IUCN’s Declining Amphibian Populations Task Force, to which I belonged, was one of the few large scale efforts addressing what is now known as the “Disappearing Amphibian Crisis”. Today, with legions of biologists and hobbyists at work on the problem, we still do not fully understand why nearly 200 species have become extinct in the last 20 years – a rate 200x that of what might be “expected”. But we do have some insights, one of which was highlighted in a recent journal article (Philosophical Transactions of the Royal Society (Biology) . It appears that stress, much of which is in response to what we are doing to amphibian habitats, is worsening the effects of normal pathogens and diseases.

Parasites and Insecticides: a Confusing Scenario

As the reality of worldwide amphibian declines became apparent, herpetologists and private citizens began noticing increasing numbers of deformed and dead frogs. In 1995, school children in Minnesota made headlines when they found dozens of deformed frogs in a local pond. Since several chemicals are known to cause growth abnormalities, researchers began focusing on pollutants. At the Bronx Zoo, I worked with a veterinarian who studied African Clawed Frogs, and was amazed to see ovaries develop in males that had been exposed to Atrazine (a common insecticide).

But pollutants turned out not to be the whole story…a parasite also played a role. The creature involved needs to infect both a frog and a wading bird in order to complete its life cycle. Amazingly, it lives within a tadpole for a time and “re-programs” the development of the hind legs as metamorphosis occurs. The newly-transformed frog develops extra rear legs and, unable to jump very well, is likely to be caught by a heron – just as the parasite “intended”!

Actually, many parasites cause incredible changes in their hosts’ behaviors – one “directs” an ant to climb into the canopy and raise its now red-colored abdomen skyward in imitation of a tasty berry (so that it is eaten by the next essential host, a bird), another causes the host spider to build a silken shelter before dying, so that the parasite has a safe place in which to emerge, and so on…

Are Pathogens Changing?

Amphibians evolved some 300-400 million years ago, long before the dinosaurs, and they’ve likely been battling parasites similar to those described above for much of that time. The same can be said of other fungi, bacteria and viruses that attack them.

Yet it seems that certain pathogens and diseases, despite being around for centuries, are now causing unprecedented amphibian population declines and extinctions. For example, Chytrid fungus, first identified as a serious threat in 1999, may be responsible for the disappearance of nearly 200 species. Although termed an “emerging disease”, it was likely present all along, but is now spreading more rapidly, and having a more devastating effect on its victims. This trend is seen among frogs worldwide (salamanders and caecilians are not as well-studied) – many pathogens are more common now than in years past, are spreading to new habitats, and are causing unusually high mortality rates.

The Role of Stress

According to the article referenced above, multiple stresses may be weakening amphibian immune systems, rendering them unable to battle common illnesses. We see this in captivity all the time – animals that are assailed by inappropriate temperatures, hostile tank-mates or poor diets often fall victim to parasites and diseases that would have been handled by the immune system had conditions been ideal.

One stress factor can depress the immune system (in zoos, birds moved to a new exhibit often succumb to Aspergillosus infections, an ever-present fungus that typically causes no problems). Currently, many amphibians are exposed to pollution, climate change, introduced species, habitat fragmentation and other stressors simultaneously. Small wonder that at least 2,500 species are believed to be in decline.

Permeable skins that allow for the passage of harmful chemicals, and the typical need for two distinct habitats, predispose amphibians to difficulties when environmental changes occur. However, there is evidence that similar processes are at work among other groups as well (please see this article on snake declines).

What’s Next…What Can I Do?

Please be on the alert for deformed amphibians and signs of population declines, and post your observations here. I can help you to get the information to organizations that can put it to good use. Also, a colleague of mine is now involved in Amphibian Ark, a fine conservation group which can provide guidance if need be.

Please see the articles linked below for information on IUCN surveys and other efforts that utilize volunteers.

Please also post your questions and comments below…I’ll be sure to respond quickly.

Thanks, until next time,

Frank Indiviglio