Just a few years ago Day Geckos were rare captive animals, highly sought after by collectors. Specimens were available infrequently and only limited captive breeding had occurred. European fanciers, especially in Germany, were having the best success in maintaining Day Geckos. Near the end of the 1980's a wave of Malagasy imports began to enter the United States' markets. Included among these animals were the previously elusive Day Geckos. One of the largest and most spectacular of the Day Geckos is the Giant Day Gecko, Phelsuma madagascariensis grandis. At the turn of the decade, an adult pair could be purchased for $200.00 but captive-bred juveniles were not available. Thankfully since that time the care and breeding of the Giant Day Gecko has become easier as more people have kept them and information has circulated as to the proper husbandry of the species. In just a few short years, captive-bred individuals have become the norm rather than the exception.
My wife and I obtained a male and two female adult, imported Phelsuma madagascariensis grandis in the fall of 1990. For the first year and a half, the trio was maintained in a 15"x24"x30" enclosure made of wood and plastic. Lighting was provided by an incandescent bulb and a fluorescent Vita-Lite. Diet consisted of a rotating selection of crickets, mealworms, waxworms and baby food, usually banana or apricot. All insects were dusted with a calcium powder preparation prior to feeding, and a vitamin powder was mixed into the baby food.
In the summer of 1991, one of the two females laid 7 eggs, an initial single egg followed by 3 doublets. Six of these eggs subsequently hatched. Incubation temperature varied, ranging from 78 F. to 88 F. Eggs hatched after incubating for 74 to 82 days. Unfortunately, we were never able to observe mating, egg deposition, or hatching. The female did not have eggs that were visible through the skin over the abdomen, as has been reported for other geckos. Eggs usually were deposited in the center of a Sanseveria plant in the enclosure or in crevices in a large piece of wood. Soon after the final egg was deposited the female had to be separated from the male, as she was exhibiting signs of calcium deficiency.
In 1992, the remaining pair of geckos was transferred to a larger enclosure: 3'x3'x5'. This enclosure was a metal-walled cabinet with front glass doors and an open screened top and back. Lighting was as before, with the daylight cycle timed to coincide with the local day length. Soon after the move, the first female juvenile from the previous year was introduced into the cage, the remaining juveniles having been sold in the interim. No breeding was seen during the year and no eggs were discovered. Vocalizations were heard over the course of the summer, however.
In the spring of 1993, two singlet eggs were discovered in the enclosure. Both females exhibited bite marks on the neck region, and vocalizations were heard at an increased frequency. Early one morning, just prior to the timer activation of the lights, I happened to be in the room where the geckos are housed. The lights came on in the enclosure, and the following series of events was witnessed and photographed:
The male gecko ran up one wall to the younger female, who was facing downward at a 45 degree angle. He stopped just short of her, and each began moving their heads from side to side in a jerky fashion, flicking the tongue in and out rapidly at the same time. Each vocalized a number of times. The sound was a low raspy whirring sound: "Kcck" The male then moved up to the female, positioning his head next to hers. She did not move, and after a moment he began to circle her, whereupon she turned until she was facing up. The male, from below and to the left of her, grabbed her neck in his mouth, stretching the skin over her calcium sacs. (1) After the initial vocalizations the pair remained silent.
The female did not move while the male put his front right, and then back right, foot on her back. He then moved over her to her right side, although he still remained on top of her, holding the left side of her neck in his mouth. (2) The male would hold this skin in his mouth the whole time mating occurred.
Using his rear right foot, the male began to lift the lower abdomen and tail section of the female. He swung his body under hers and began to move his groin so as to come into contact with her. (3) At this point he was anchored to the wall by both front feet (on either side of the female's head) and his back right foot (almost directly under the female's groin area). His left foot was firmly gripping the female's back over the base of the tail. The female had by this time become rather bent from side to side and was anchored by all but possibly the right back foot, which could not be seen due to their positions. (4) This position lasted for a number of minutes.
Rather suddenly the male disengaged from the female, who paused for a moment and then scampered away to hide behind a rock near the bottom of the cage. The male moved to a horizontal branch where he proceeded to lick his vent for two or three minutes. One small portion of the hemipenis could be seen initially but was retracted after a few moments.
Unlike previous experience, visible eggs have been seen through the belly of the younger female. (5) Within three days of observing eggs through the skin a doublet was discovered in the cabinet.
As of this writing thirteen eggs are incubating, two of which have hatched. The previous hatchlings all turned out to be females but we hope that some of this year's hatchlings will be male.
Originally published in Reptile & Amphibian Magazine, May/June 1994, pages 12-19.
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