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

The technology behind amphibian and reptile lighting has come a long way since I began working at the Bronx Zoo, when “black lights” and the sun were our only UVB (Ultra Violet B radiation) options.  Today I’ll review an important herp husbandry innovation, the compact UVB fluorescent bulb (note: bulbs are referred to as “lamps” in technical papers).  My experiences have been positive, but some reptile-keepers have raised concerns, so I’ll address them as well. Please be sure to post your experiences and ideas below, as we still have much to learn about this important topic.

Reptiles, UVB and UVA: a Quick Primer

Most heliothermic (basking) lizards, turtles, and crocodilians need exposure to UVB light rays with a wavelength of 290-315 nanometers in order to synthesize Vitamin D3 in their skin.  Vitamin D3 allows these animals to utilize dietary calcium.  Without D3, dietary calcium is not metabolized and metabolic bone disease sets in.  Snakes, highly-aquatic turtles, nocturnal lizards, most amphibians, and certain others can make use of dietary Vitamin D, but most basking species rely on the skin-synthesized form. Read More »

Chameleons are spectacular creatures to care for, but they are almost “too interesting” for their own good.  Drawn by their beauty and unique-to-bizarre characteristics, many rush into chameleon care without proper preparation.  None are suitable for beginners, but if asked to recommend a large, colorful species to an experienced keeper, I would choose the majestic Panther Chameleon, Furcifer pardalis.  While not as hardy as the Veiled Chameleon, Chamaeleo calyptratus, the Panther is adapted to environmental conditions that fluctuate wildly, and this seems assist its adjustment to captivity.  It is also an excellent study subject…recent studies have revealed new insights into the relationship between chameleon basking behavior and diet (please see below).

I’ve worked with many chameleon species in zoos, and can attest to the difficulties involved even when one has sufficient space and supplies.  Please read this article and those linked under “Further Reading” carefully, and post any questions below. Read More »

My professional experience with captive reptiles, amphibians and other creatures extends back over 4 decades, with much of that time being spent at the Bronx Zoo. For the past 24 years, I’ve relied heavily upon Mazuri animal diets, as have many of my zoologist colleagues worldwide. From turtles to elephants and hamsters to cassowaries, Mazuri formulates more carefully-researched foods than does any other company. I recently had occasion to experiment with and read about Mazuri’s High Calcium Cricket Diet, and am quite pleased with the results. In the following article, I’ll also highlight some other useful products for crickets and similar feeder insects.

The Calcium: Phosphorus Ratio

In order to maintain optimum health and normal growth, the foods offered to reptiles and amphibians should (depending upon the species) contain calcium and phosphorus in a ratio of 1:1, 1.5:1 or 2:1. Crickets and many other feeder insects in their natural (“un-supplemented”) state have a calcium: phosphorus ratio of only 0.3:1. Read More »

The Emerald Tree Boa is extremely popular in zoos and private collections, but its life in the wild remains relatively unstudied.  What little we have learned has come mainly from chance observations rather than long-term studies.  Cryptic coloration, nocturnal ways and a life spent high in tropical forest canopies or dense brush has served to shroud their habits in mystery.  But each bit of knowledge has helped us to better keep and breed this magnificent snake.  For example, studies of the Emerald Tree Boa’s natural habitat have revealed the importance of providing captives with humid but airy enclosures, and temperatures that are somewhat lower than one might expect.

Range

Emerald Tree Boas are native to two distinct but adjacent areas of northern South America – the Guyana or Northern Shield region and the Amazon Basin.  Individuals from each area differ somewhat in appearance, and some have suggested that 2 subspecies should be named.  Corallus batesii has been proposed for the Amazon Basin population by those who believe that 2 distinct species are present.

Description: Differences between the Two Major Populations

Snakes from the Guyana Shield region, which encompasses parts of Surinam, Guyana, French Guiana and Venezuela, are light green in color (often described as “lime green”), and have noticeably larger head scales than do those further south. Read More »

Boa Care: Emerald Tree Boa Terrariums, Husbandry and Diet

The breathtakingly-beautiful Emerald Tree Boa (Corallus caninus) has long topped snake enthusiasts’ wish lists.  Demanding husbandry requirements and a somewhat surly disposition adds to its mystique.  I’ve had some success in breeding this species in zoos, and private keepers have made important strides in recent years, but misconceptions and information gaps persist.  Today we’ll discuss Emerald Tree Boa care; please look for my article on its interesting natural history in the near future.

The Terrarium

Cage height is an important factor.  Observations of animals kept in small enclosures have led to this snake being labeled as “sedentary”, but those in large, complex habitats move about quite a bit.

An enclosure measuring measuring 4 feet by 3 feet x 4 feet in height is ideal for a large adult.  Males and smaller females may get by in 75-100 gallon aquariums turned on their narrow ends, but custom-made cages are a much better option.

Cages that open from the front are preferable, as Emerald Tree Boas are stressed by approaches from above (perhaps because birds of prey are their major predators).  In front-opening terrariums, they will often remain on their perches while the cage is serviced (sparing snake and snake-keeper stress and injury!).  A variety of commercial cages are suitable for youngsters.

Cage Furniture

Well-anchored branches of varying thicknesses, both forked and straight, should be installed.  Emerald Tree Boas often coil at the spot where 2 forks of a branch diverge, so be sure to include several.

Pots of tall, sturdy live plants (philodendron, small ficus trees, snake plants) should be placed about the cage to provide security and aid in humidity control.  Artificial plants hung from branches and the cage top can also be used as cover (I favor this model).

Substrate

Newspapers and washable terrarium liners work well as substrates in aquariums.  In larger enclosures, cypress mulch or forest floor bedding will allow for easy spot-cleaning and help to raise the humidity level.

Light

UVB exposure is not required, but UVA bulbs may encourage natural behavior, and will bring out the true beauty of their coloration.  A day/night schedule of 12:12 hours should be maintained.  Red/black reptile “night bulbs” will allow you to observe nocturnal behavior.

Heat

This species is closely associated with rainforests in most keepers’ minds, and this sometimes leads to a misunderstanding of their needs. Arboreal snakes experience greater temperature and humidity fluctuations than do terrestrial snakes living in the same habitats.  Emerald Tree Boas prefer cooler temperatures than one might imagine.

Incandescent bulbs should be used to maintain a temperature of 75-77 F, and a basking spot of 85 F.  At night, a dip to 72 F is beneficial  A ceramic heater or red/black reptile “night bulb” can be used to provide heat after dark.

Large enclosures are necessary if a thermal gradient (areas of different temperatures) is to be established.  Thermal gradients, critical to good health, allow snakes to regulate their body temperature by moving from hot to cooler areas.

Humidity

These moist-forest denizens (please see photo of typical habitat) require humidity levels that fluctuate between 60 and 90%. Humidity can be increased via manual spraying, moistening the substrate and commercial reptile misters.  Humidity should be highest during the day, and decline with the temperature at night.

Wet conditions and stagnant air will lead to skin diseases.   Ample air flow, often overlooked in the past, is now recognized as critical to good health.  The terrarium’s top should not be covered with glass to increase humidity; a small fan may be employed to circulate air if necessary.

Feeding

Emerald Tree Boas are best offered food via tongs.  Slowly moving the food in front of the snake, or lightly touching the jaws or body, often induces a strike.  Juveniles feed primarily upon lizards and frogs, and many refuse mice.  Scenting small mice (fuzzies or hoppers) with a lizard or shed lizard skin may be helpful.

Chicks, quail, gerbils or (for newborns) house geckos may spur picky feeders to take a meal.  In time, these can be used to scent mice.

A Note on Meal Size and Frequency

Meal size is an important factor in maintaining good health.  Always use smaller food items than you might for similarly-sized snakes of other species.  Half-grown rats suffice for even the largest individuals.  Regurgitation, a very common ailment, seems linked to overly-large meals and excess food intake.

Emerald Tree Boas have extremely efficient, and somewhat “slow”, digestive systems, and do not usually defecate after each meal.  They need comparatively little food, and typically regurgitate if overfed.  Snakes confined in small cages that do not allow for sufficient movement often have trouble passing fecal material.  Forcing the animal to swim may help.

Newborns should be fed every 10 days; juveniles at 2 week intervals.  Adults require, on average, 2 mice or a small rat every 3 weeks.

Water

A bowl should be provided, but most individuals will only take water that is sprayed onto their bodies and the foliage.  Some will drink from a watering can tilted in front of the mouth.  Punctured plastic containers placed on the cage’s top and small waterfalls may also be utilized.

It can be difficult to provide enough water via misting.  Dehydration, indicated by skin ridges and sunken eyes, is not uncommon.  At the Bronx Zoo, I’ve injected water into dead rats to accommodate Amethystine Pythons and other reluctant drinkers.  Please post below for details.

Handling

Although individuals vary, Emerald Tree Boas rarely accept handling and will bite if forcibly removed from their perches.  Their teeth, some of which may reach 2 inches in length, can inflict serious injuries, especially if an eye or nerve is struck.  In common with many arboreal snakes, they have quite a long strike range. Emerald Tree Boas are best considered as animals to observe and study rather than handle.

Detachable perches simplify handling, as some individuals will remain immobile if perch and snake are relocated together.  Still, a shield and/or a snake hook should be kept between yourself and the animal.  Others can be induced to leave their perches and climb onto a hook, but experience is needed.  Constructing the cage in a way that allows for cleaning without moving the snake will limit stress and strikes.

 

 

Further Reading

Natural History & Care of Boa Constrictors & Related Snakes

Breeding Brazilian and Colombian Rainbow Boas