At some point, lizard keepers usually think about breeding their favorite species. The ever-popular Leopard Gecko, Eublepharis macularius, is an excellent choice for both novice and advanced hobbyists. It is a reliable breeder, yet the conditions that must be established if one is to succeed are similar to those required by many other species; a beneficial learning process is thus ensured. Experienced breeders have developed a huge array of color and pattern morphs, and many enjoy “tinkering” with the genetics of these in order to create unique new gecko strains.
Note: Before attempting to breed any animal, it is important that you arrange homes for the youngsters. Please don’t assume that friends or pet stores will accept them…plan ahead.
Distinguishing the Sexes
Directly above the vent, you will see a series of “V” shaped bumps, the pre-anal pores. These are large and readily-visible in males and less-evident in females. Between the vent and the base of the tail, mature males also exhibit a pair of bulges, beneath which are the hemipenes. Please see the article below for a complete guide to determining your pets’ sex.
Breeding Age
Captive Leopard Geckos usually grow faster than their wild counterparts, and may become sexually mature at age 12 months. Year-old males may be bred, but it is preferable to wait until females are 18-24 months old. An even better indication of breeding readiness (for females) is weight, with 50-60 grams being ideal. A small postal or digital scale can be used to weigh your geckos.
“Almost Spontaneous” Breeding
Wild Leopard Geckos are brought into breeding condition by changes in daily temperatures and light levels. Captives may be stimulated by slight environmental changes, and so may seem to breed spontaneously. Separating and reintroducing a pair may also be effective.
While working at the Bronx Zoo, I even tried the old-timer’s technique of placing monitors and various pythons in a sack (or, rather, separate sacks!) and driving them about on a golf cart for awhile. Amazingly, this sometimes prompts breeding behavior – it seems that the “centers” for adjustment-to-change and reproduction are closely “wired” in some herps!
Conditioning Breeders: Cooling Off Period
However, a more reliable breeding method is to gradually reduce temperature and day-length, preferably in autumn. Feed your geckos well, perhaps increasing dietary variety, during the late summer. Cease feeding 10 days prior to the autumn cool-down, and do not begin dropping temperatures until the animals have defecated. Chilling your geckos before they have passed all wastes will lead to fatalities.
Drop the temperature by 10 F increments over 2 weeks or so, until 50 F is reached. Reduce the day/night cycle to 10 hour day and 14 hours night at the same time. Turning off basking lights and moving the tank may be used in the early stages. For the actual 5 week cooling off period, you’ll need a location that maintains 50 F. Basements and attics are often suitable, but be sure to test the site with a “high-lo thermometer” or other device that records temperatures over a 24 hour period.
Geckos in winter cool-down should be provided a hide box stocked with slightly moist sphagnum moss and a water bowl.
Conditioning Breeders: Warmth and Diet
Warm your lizards up slowly after their 5 week rest. Begin with small meals, progressing to a full diet once they are feeding well. Gravid females need ample calcium reserves, so use ReptoCal or ReptiCalcium on every meal, along with a vitamin/mineral supplement (i.e. Reptivite with D3) 2-3 times weekly. Although not essential, an occasional pink mouse may be offered at this time as well.
Please see this article for further info on providing a balanced diet.
Pairing and Breeding
In order to limit territorial aggression, place your male into the female’s cage. One male may be kept with several females, but trios usually work out best (some breeders keep a single male with up to 10 females…I’m assuming such males are fed very well, and are good at negotiating domestic squabbles!).
Female Leopard Geckos produce 2 eggs, which are often visible beneath the skin as they develop. Remove the male once copulation has been observed, or you notice a weight gain; watch also for overly aggressive males. Copulation is accompanied by biting about the neck, but continual harassment of the female is not normal.
A nest box stocked with moist sand, vermiculite and sphagnum moss should be provided and checked daily. Eggs may also be deposited in the hide box.
Even though we know a great deal about Leopard Gecko breeding, it is important to take notes on behavior, diet, temperature and other details. One never knows where the next unexpected discovery will pop up, and lessons learned while keeping common species are often applicable to endangered lizards…the fate of more and more of these, unfortunately, rests with captive breeding programs.
I’ll cover egg incubation and rearing the young in the future. Until then, please write in with your questions or comments.
Further Reading
Leopard Gecko Color Morphs (with photos)
Leopard Geckos image referenced from wikipedia and originally posted by Angela Rothermann
Leopard Gecko juvenile image referenced from wikipedia and originally posted by Jerome 66