Snake Egg Incubation
Dr. Jenni Bass
The serious reptile breeder keeps extensive records, but even the casual hobbyist will learn a great deal and have more success and a greater understanding of his reptiles if he keeps records. The short term value of records is not always clear, but in time will lead to a greater number of healthier pet snakes. Dates of emergence from dormancy, pre-ovulatory shed, introduction of male and female.
Mark the eggs and the container, such that you are able to identify which pair produced which eggs. In addition, note the following points specific to the breeding of oviparous snakes:
Observed mating behavior or actual copulation.
Date of pre-lay shed and introduction of nest.
Date eggs are laid, number and quality of eggs (eg. thin, rough or unshelled eggs), and any difficulty in laying.
Incubation parameters including temperature and humidity ranges and unusual events such as power cuts or earthquakes.
Any infertile eggs, as well as any that die during development. Note the date of death in shell, as accurately as you can. This information can form patterns that may help you to refine your incubation techniques.
Maternal health: Although females who are not receiving adequate nutrition may lay eggs, there will likely be a reduced fertility rate, more deaths in shell and decreased survivability after hatching. The developing fetus receives calcium from the egg shell and from the yolk, so a healthy calcium balance in the mother snake is important. Incorrect housing of the female and health concerns such as obesity are significant contributing factors to low hatch rates. Snakes who have had difficulty laying in the past are in general, more likely to have future difficulty.
Parental factors: Older parents increase the likelihood of poor quality eggs and sperm. Snakes of the same species may have wild origins that are sufficiently different so that the combination of their genetics and incubation requirements leads to decreased hatchability. As far as possible, try to pair snakes of like geographical origin.
Premature assisted pipping. Snakes removed from the shell too early often do not survive. If not absorbed, the yolk sac is an ideal medium for bacterial growth, which can quickly infect and kill the young snake.
Incubation problems. Excessive fluctuations in temperature, prolonged hot or cool periods, excessive drying or wetting of the eggs and excessive vibration are the most common reasons a fertile egg will fail to hatch.
Records can often point to trends or unusual occurrences that may explain the death of the egg or of the hatchling.
Although less is known about the reptilian egg, as compared to the avian egg, a reptile veterinarian may be able to rule in or out several possibilities by performing an egg post mortem. This must be done quickly, as the egg will undergo rapid autolysis, that is, it will decompose quickly once the embryo has died.
Your veterinarian can also do a histology exam, which examines tissues microscopically. Tissue from the egg can be cultured to identify possible bacterial disease. Your reptile veterinarian can also provide an objective eye, which may be able to see a pattern in your records to explain losses.
Start with healthy, well-kept parents. Be as sure as possible that they are of similar geographic origin. Learn the species' natural history and nesting conditions by talking to experienced breeders and keepers. Record all data related to parental activity, eggs and incubation parameters. Realize that assisted pipping may save the animal, but may also kill it. There are no hard and fast rules. Make use of your reptile veterinarian and of successful breeders of your reptile's species.