Expert tips on breeding the Kenyan sand boa.
While Kenyan sand boas (Eryx colubrinus) have yet to achieve the popularity of corn snakes or ball pythons, they are still kept and bred in significant numbers, and are considered by many to be among the best choices for a pet snake. They reproduce readily in captivity, so obtaining a captive-bred specimen is never a problem.
My Kenyans usually start courting behavior when introduced in May through July. This time frame varies, depending on a number of aspects, including the amount of food the female has taken (she needs to have adequate body weight for breeding) and the weather. I have had baby Kenyan's born in every month from October through April.
A two-month period of cooling is a good way to get your Kenyans in the mood for romance. This needs only to be a slight drop in temperature to have the desired effect. Simply shutting off the heat source to the enclosure and leaving them at room temperature will do the trick. An overall habitat temperature in the mid-70s is acceptable for Kenyan sand boa brumation. If the room is drafty, or there is a risk of the temperature dropping below 70 degrees, a lower-wattage heat source will keep it out of the danger zone.
I usually shut the heat source off for my sand boas around Christmas, and start warming them up around the end of February. Some keepers prefer to gradually lower the temperature over a period or two weeks or so, some just drop the temperatures suddenly. I have done it both ways, with no negative results. I do, however, stop offering food at least two weeks prior to shutting off the heat source.
Some years I have simply been too busy to focus on their cycling, and they still end up reproducing just fine. In other words, cooling them does help, but it is not necessary to breed this species successfully.
If you do cool your sand boas, be sure they have sufficient body weight, and do not feed them two weeks prior to, and during, the cooling period. They will not be able to digest their food properly without their regular heat source. Always ensure that fresh water is available to the snakes, even during brumation. Females should be at least 2 years old to breed, but males are occasionally to be reproductive at less than one year. A length of no less than 21 inches, and a weight of 325 grams, is required for breeding females. Larger is better. If an extra year is needed for a female to obtain the desired size, it will be worth the wait. The litter size is almost always larger in larger females, and the reproductive process will be far less stressful for the animal.
A week after cage temperatures return to normal (95 degrees Fahrenheit for the hotspot and 80 degrees for the cooler side), start offering small prey items, twice weekly. After a couple of weeks, I introduce my males into the females' cages. More often than not, courtship occurs immediately, or within a few hours. I leave them together for three or four days, then put the male back in his own enclosure for the rest of the week, offering food to both snakes. I follow the same method for all of my Kenyan sand boas for a month or so, until there is no more interest in breeding or I am convinced that they got the job done.
In the rare event that desired a male is not showing any interest in breeding, I will introduce a second male to the enclosure. This will often heat things up instantly, and combat between the two males will transpire. I have never seen any actual damage done, but I have heard about males inflicting nasty bites on one another, so I never leave them unattended. Five minutes of combat is usually long enough to rouse the leisurely male into waking up and smelling the pheromones!
A gravid female sand boa will seek out belly heat to help with the development of her babies. Be sure to provide this via a heat cable with a thermostat or an undertank heating pad. The gestation period is about four to six months, with the temperature having some influence on the birth date.
My females will usually continue feeding throughout most of their term, but I offer them smaller meals to allow room for the developing babies. Usually, as the due date approaches, females will refuse food altogether.
Kenyan sand boa does not lay eggs. They give birth to live young. No incubator needed. The female boa retains the embryos inside her, and she delivers the fully formed babies encased in individual membranes. Often she consumes unfertilized ova (slugs) at the time of delivery.
Out of all the sand boa litters I've had born, delivery has always taken place overnight. Litter sizes have ranged from six to 18, but I have heard of large females having more than 20 babies.
When the babies arrive, separate them from the mother and set them up in a plastic shoebox-sized container with small air holes, a heat source, paper lining, hiding places and a small water bowl. The mother can be offered small prey items again immediately, but she may enter a shed cycle first before accepting food. The babies should be offered their first meals after they complete their first shed, which is in about a week from the birth date.
I keep the entire litter together in the same container to start. I offer one pinky mouse, dead or alive, and wait to see which baby takes it. I remove this snake to its own container, and repeat the process until they have all taken their first meal. This may be done over the period of several days. This method has worked incredibly well for me, and I use it for many of my other types of snakes with excellent results. This type of group feeding may inspire predation through a sense of competition, or simply get them into a natural feeding mode because of the motion and excitement. It's a good idea to keep an eye on the progress, to ensure that two snakes don't go after the same pinky, which can result in one snake being accidentally swallowed by another.
I believe the Kenyan sand boa is in a good place right now, in terms of a moderately low-investment breeding animal. There is a devoted and growing following for the species, and with new morphs emerging, the demand is increasing and the value is holding firm. Because there are not huge numbers being produced, the market is not flooded, so breeders are not stuck with excess offspring. These factors, combined with the snake's willingness to readily reproduce in captivity, make it an excellent choice for an entry-level or intermediate breeding project.
Darren Boyd is a professional musician, herpetoculturist and all-around troublemaker. His founded his reptile breeding and education-based business, The Reptile Rainforest, in 1995. Visit him on the Web at reptilerainforest.com and darrenboyd.com.