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.
click to enlarge
|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.
All photos and text courtesy Steven T. Osborne - Professional Breeders
New & Updated Business Listings
Looking for a reptile or amphibian related business? A reptile store, breeder, importer,
maunfacturer or supplier? Our business directory lists some of the most popluar herp businesses in the world.
|Locate a reptile or amphibian business by name: