BREEDING LEOPARD GECKOS
Authored by Ron Tremper Leopardgecko.com
Leopard Gecko Egg-Laying and Incubation
Note that no Leopard gecko has ever laid more than two eggs per clutch.
Leopard geckos lay one or two eggs for their first clutch and on average a total of eight eggs for their first breeding year. After the first breeding year, the healthiest individuals may produce as many as eight two-egg clutches (16 eggs) per year. The average in our commercial colony is 5 clutches per season. Resulting in 8.4 babies per year, per female, due to infertility and variables related to embryo death. Once a breeding season begins, you can expect females to lay a clutch every 15-20 days over a 4-5 month period. As noted earlier, after the fifth or sixth year of breeding, egg production declines until a female reaches menopause. Note that no leopard gecko has ever laid more than two eggs per clutch, and that it is common for older females, six or more years old, to only lay single egg-clutches. We will reiterate what we have stated before: Careful record keeping is absolutely necessary for the serious breeder. Tracking the female’s age, egg production, hatch rate and partners, will optimize the production capability of a commercial operation.
When a leopard gecko is ready to lay, you can clearly see the two elongated, shelled, white eggs (see photo) through her abdominal wall, and with experience, you will also notice slight bulges on the sides of the body when viewing her from above. These physical clues of impending oviposition are coupled with pre-laying behaviors, such as restlessness, digging, resting over the heat source, and a disinterest in feeding. As soon as you notice the bulgy appearance and the above behaviors, it is time to properly prepare for eggs to be deposited.
Years ago, some researchers found that they could remove the water dish (to prevent females from laying in them) and in a rather small, high humidity environment merely spray the cage sides and substrate to provide for egg-laying. This procedure is not recommended because it can stress some females and lead to egg-binding. Today, the technique employed by virtually everyone is the use of a laying box.
For one or two females an opaque plastic container of any type can suffice for a laying chamber as long as it measures at least 6-7” in diameter and 4” high. For cages housing 3-5 females, a plastic shoebox is ideal. In both instances, since leopard geckos are surprisingly good climbers, a two-inch hole should be made in the box lid. Placing the hole on the side will also work, but these geckos will tend to kick out good amounts of the laying medium over time.
Whatever you use, you must keep the egg-laying medium moist at all times
A good choice of egg-laying medium for placing at the bottom of the laying box is peat moss or vermiculite. I discourage the use of vermiculite for this purpose. Although many herpetoculturists have experienced no problems with the use of vermiculite in this fashion, many leopard geckos will eat this material, which can cause harmful impactions. Whatever you use, you must keep the egg-laying medium moist at all times. A pistol-grip hand sprayer is perfect to have nearby for this task. The moisture level should feel like freshly dug earth. If it clumps when you squeeze a handful together, then it is too wet.
The egg-laying box will also function as a shelter/resting place, which will be essential for giving leopard geckos security and provide contact with a high relative humidity/moist substrate environment, ensuring proper shedding; especially of the toes. If when checking for eggs, you notice eggs with dents or geckos with skin shed problems then your laying box is kept too dry.
Some hobbyists, when they first notice a female is carrying eggs, choose to move it to a separate egg-laying enclosure; this is not a good idea. The stress of moving gravid females to unfamiliar surroundings, just before they are ready to lay, often causes them to deposit eggs outside of the egg box or in the water dish. If you see this, then you know that something is amiss. It has been found that 15-20% of eggs found floating in a water dish, sometimes for hours or days, would still hatch.
Freshly laid eggs are soft and sticky, but when fertile, quickly become turgid, with the feel of a stale marshmallow. You can handle newly laid eggs without concern about rotation issues for the first two weeks. A good egg is very resilient. More than once I have played soccer with dropped eggs or outright bounced them off the floor causing no harmful effects.
Egg Laying and Incubation Part 2, will follow soon…