kingsnake.com - The Captive Breeding of Colubrid Snakes

The Captive Breeding of Colubrid Snakes:

This document, written by Steven T. Osborne, was originally published as a 4 part series in the 1982 edition
( Volume 4: Number 3,4,7, & 9 ) of the San Diego Herpetological Society Newsletter.

Part III. Preparing for Egg Laying and Hatching of Eggs

This article is the third in a series pertaining to husbandry and captive breeding of North American colubrid snakes in the genera Elaphe, Pituophis, and Lampropeltis. This article specifically pertains to (1) Supplying gravid females with a suitable egg-laying site, and (2) incubation and hatching of eggs.

As stated in Part II, females will usually undergo a pre-oviposition shed shortly before egg laying. On the day this occurs, it is important to provide a suitable egg-laying site that the female will be satisfied with. A successful way to accomplish this is to use moist sphagnum or peat moss as a substrate inside a container. Typical containers would be tupperware or a large butter dish with an entrance hole cut in the top or side large enough for easy passage. Two to 3 inches of substrate with ample room for the snake to move around determines the container size.

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An occurrence that is often distressing to the keeper is the excited activity some females exhibit several days prior to egg laying. This might be referred to as "nesting search" and is a normal behavior. This behavior is characterized by movement in and out of the egg-laying container and all around the cage. At the point when egg laying is due, the female will normally settle down in the container and lay her eggs. It is important to remove the water dish from the cage shortly before the egg-laying date as females may choose this as an alternative egg-laying site, which can result in drowning of the eggs.

At the time when egg laying occurs, females deposit eggs that often connect to each other via a bonding substance that coats the outside of each egg. If the eggs are found soon after being laid (e.g., 30 minutes), it is possible to separate them. This procedure is delicate and requires sensitive handling. The reason for doing this is mainly to separate possibly infertile eggs that may mold and possibly affect adjoining fertile ones. Fertile eggs generally appear bright white and firm rather than soft and discolored. A clutch of infertile eggs is often laid earlier than expected-following the pre-oviposition shed-and the eggs are often not all laid in the same 24-hour period. If the eggs are solidly connected to each other, it is best to leave them that way. Eggs in the wild hatch in this manner, and they are easily hatched this way in captivity.

Before egg laying occurs, an incubation container should be ready in order to set up the eggs as soon as they are laid. An ideal incubation substrate is vermiculite moistened with water. The recommended ratio is 1 : 3/4 (vermiculite to water) by weight. Plastic shoe or sweater boxes have proven to be excellent incubating containers.

The specifics for the set-up are:

Plastic shoe or sweater box with lid;
A 2-to 3-inch layer of moistened vermiculite in box;
A 1/8-inch hole drilled in opposite ends of the box for ventilation (otherwise it is a closed system, which could lead to embryo asphyxiation);
Single eggs or the entire clutch partly buried in the vermiculite with 1/3 to 1/2 of each egg exposed; and
Light misting with water every 2-3 weeks or as needed to maintain the original vermiculite-to-water ratio.

The final and a most important aspect of incubation is temperature. For these three genera, a constant temperature of 74-82�F seems ideal. Temperatures over 87�F should be carefully avoided. Eggs incubated as low as 65-70�F will hatch successfully but take more time. Average hatching times for a few species at 80 degrees F are:

Lampropeltis getulus and L. triangulum 60-65 days Lampropeltis mexicana ssp. 55-65 days Elaphe guttata and E. obsoleta 55-65 days Pituophis melanoleucus ssp. 68-75 days.

Approximately 2 days can be added for every 1�F that the average incubation temperature falls below 80�F (e.g., 70-75 days for Lampropeltis getulus at 75�F). A table or shelf serves as a suitable location to keep the eggs if the temperature there stays within the 65-82�F range. Usually all initial slitting of the eggs by the hatching snakes takes place within a 48-hour period. Once the egg is slit, 12-48 hours may pass before the hatchling emerges. I have found that the most satisfying and enjoyable time in captive breeding is when the eggs hatch. It tells you that your captive breeders are performing to their best potential in your breeding situation.

Click Here for Part IV

All photos and text courtesy Steven T. Osborne - Professional Breeders