Snakes have two basic reproduction strategies. The first involves the retention of the fertilized eggs within the body of the female wherein they develop. When the embryos are fully developed, the offspring are born, appearing like miniature adults. The boa constrictors, water and garter snakes, and rattlesnakes possess this reproductive strategy and are considered ovoviviparous. The second such strategy involves the actual deposition of oblong, leathery-shelled eggs within the environment in which the embryos develop. At the completion of embryonic development, the offspring hatch, appearing like miniature adults. The pythons and rat and milk snakes possess this reproductive strategy and are considered oviparous. In either case, the newborn baby or newly hatched are fully capable of fending for themselves and receive no parental nurturing.
Many snake species will readily mate in captivity. One mating may result in up to 3 clutches of eggs or 3 “litters” of live young. This is because sperm can be stored within the reproductive tract of the female after insemination.
The proper pairing of snakes according to age and sex is essential if reproduction is to be successful. The sexing of most species of snakes can be difficult because males generally resemble females. Male pythons and boa constrictors possess a spur on each side of the vent. Some females have spurs, but they are usually smaller than those possessed by males of the same species and body size although these observations can be misleading at times.
Snakes under 18 inches long can usually be sexed by exerting pressure on the tissues surrounding the vent. Male snakes have paired hemipenes (elongated, spurred structures used during copulation) that can be extruded with this maneuver. The widely accepted method for sexing most snakes over 18 inches in length requires the use of specialized sexing probes. These elongated, blunt-tipped instruments are gently inserted into the vent and directed toward the tail. The probe will penetrate only a short distance in females and a comparatively much longer distance in males. This procedure should only be attempted by an experienced individual.
Artificial Incubation of Snake Eggs
The artificial incubation of fertile snake eggs is quite easy to do. A small amount of water is added to an empty styrofoam picnic chest. Then, a thick layer of peat moss, sphagnum moss, vermiculite, shredded newspaper, or paper towel is added. The eggs are then carefully introduced into this medium. Slightly moistening the incubation medium will also help prevent the eggs from drying out. Too much moisture will cause the destruction of the eggs’ contents. The relative humidity required to incubate snake eggs falls within the range of 75% to 85%. The covered styrofoam chest is then placed on a heating pad which is set on its lowest heating setting. The ideal temperature range for most incubation lies between 78º and 84ºF. The average incubation period for most snakes ranges between 55 and 60 days.