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

A female Boa (Boa constrictor) shocked herpetologists by giving birth to live young that she produced by cloning rather than mating.  What’s more, the process used to create the young is new to the animal world – it has not been seen in any other vertebrate.

Asexual Births in other Species

Asexual reproduction or parthenogenesis – producing young without mating – is well known among insects and certain fishes (including Hammerhead Sharks), some of which can even switch sexes several times.  It has also been recorded in a small number of reptiles, such as the Brahminy Blind Snake, American Whiptail Lizards and the Komodo Dragon.  Read More »

I usually recommend that aspiring snake breeders start off with live-bearing species, so as to avoid the necessity of incubating eggs.  In the Family Boidae we find a wide range of possibilities, one of the most popular of which is the beautiful Rainbow Boa (Epicrates cenchria). Although not as widely kept as its much larger cousin, the Boa constrictor, the Rainbow Boa is far easier to manage in captivity, yet grows large enough (to nearly 7 feet in some cases) to satisfy those who prefer sizable snakes.

Range and Diversity

Eight subspecies of Rainbow Boa range throughout much of Central and South America (Panama to Northern Argentina).

Black rings on a rich red-orange background mark the most highly desirable of these, the Brazilian Rainbow Boa (E. c. cenchria).  The somewhat duller but still attractive Columbian Rainbow Boa (E. c. maurus) is more commonly available.  Both of these snakes, and the remaining subspecies, may be bred in a similar manner.

Selection of Breeding Stock

Although occupying a wide range of habitats, Rainbow Boas from all locales usually respond well to similar breeding techniques.  Captive-bred animals are easier to work with than wild-caught individuals, as the “internal clocks” of wild snakes may conflict with local conditions – wild-caught animals will usually reproduce only during their normal breeding season, and after being exposed to a very close simulation of natural conditions (rainfall, temperature, etc.).

Potential breeders should be robust, at least 3 years of age and approximately 5 feet long, so that sexual maturity is assured.  Small and/or young females often give birth to a high percentage of stillborns.

Stimulating Reproduction

Despite their tropical origins, Rainbow Boas selected for breeding should be subjected to a 6 week cooling-off period, at temperatures of 68-70 F.  Over much of their natural habitat, such temperature dips are associated with rainy periods.  Increased misting may, therefore, help spur reluctant breeders, but care must be taken that the snakes dry off completely, lest fungal skin infections take hold.

Snakes slated for cooling should be fasted for 2-3 weeks beforehand (undigested food in the gut of a cool snake will spoil and likely kill the animal).  A water bowl should be available during their artificial “winter”.

At the end of the cool period, temperatures should gradually (over a 10 day period) be raised to 78-85 F, with a basking site of 92 F.  Females give birth 6-8 months after copulation, and produce an average of 10 young per litter (the range is 1 to 25).   Newborn Rainbow Boas are large enough – 14 to 24 inches – to take fuzzies or small mice as a first meal.

A Note Concerning Diet

I’ve found that Rainbow Boas often refuse favored foods after a time.  Usually, a switch from mice to rats, or vice-versa, gets them started again.

Rainbow Boas usually relish chicks, and may take gerbils, hamsters and other rodents, but these should not be used unless a steady supply is available.  Snakes that “fixate” on a difficult-to-obtain food can be trouble.  I once worked with an anaconda that refused all food but muskrats, another which took only wild-caught Norway rats, and several that “demanded” ducks.

Further Reading

Information on the natural history of the Brazilian Rainbow Boa and other creatures that live in its habitat may be found in the newsletter of The Amazon Conservation Association.

A video of a nicely colored young Brazilian Rainbow Boa is posted here.

Peruvian Rainbow Boa image referenced from wikipedia and originally posted by Damien Farrell

The Tropical Girdled Lizard (Cordylus tropidosternum) is the most readily available of the 30+ Cordylus species, and offers an excellent introduction to the group.  It is sometimes sold as the “Armadillo Lizard”, confusing purchasers who had in mind another (and, at $1,200+ each, vastly more expensive!) species with the same common name, C. cataphractus.  It also occasionally appears under the name “East African Spiny-tailed Lizard”.

Tropical Girdled Lizards in Captivity

Don’t let their inexpensive price tag mislead you – Tropical GirdledLlizards are no less interesting in appearance or behavior than their pricey cousins. In fact, the “true” Armadillo Lizard, C. cataphractus, which is no longer exported from South Africa, is one of the shyest reptiles I’ve ever encountered.

When kept properly, these southeast African natives may reward you by reproducing, always a thrill for responsible herp keepers (judging from the size of the young, the event is less thrilling for the moms – please see below!).  While not bold, they are no as retiring as most related species, and are relatively easy to observe.

Girdled Lizards give birth to 1-4 huge live youngsters.  The hatchling pictured here, born at the Maritime Aquarium in Connecticut, is one of a litter of 2 – their total mass seemed to be nearly half that of their mother.

Further Reading

Two subspecies of tropical Girdled Lizards appear in the pet trade; to help determine which you have, and for a key to other species in the genus, please see this reference.

Over the last several years I have helped to set up new reptile and amphibian exhibit areas for The Maritime Aquarium in Norwalk, CT (long known for its excellent collection of native marine life).  To learn more, please click here.