Breeding Gargoyle Geckos

The short version

• Pair females only at 40 grams or more and at least 18 months old; males at 30 grams or more, of similar size [6][16].
• Introduce the pair for a few days, watch for injuries, then separate them. One mating can fertilize a whole season of eggs [13][16].
• Expect two-egg clutches every 4–6 weeks, for about 3–8 clutches a season [6][16][17].
• Eggs hatch at room temperature, 70–78°F (21–26°C), in about 45–100 days depending on temperature; most take 2–3 months [13][16][17].
• House every hatchling alone, and protect the female's calcium with a full rest every off-season [6][17].

Gargoyle geckos are one of the easier lizards to breed. A healthy adult pair kept at room temperature will produce two-egg clutches about once a month through the season, and the eggs hatch without incubator heat. The hard parts are patience (females take 18–24 months to be ready), keeping the pair from hurting each other, and protecting the female's calcium.

Sexing

Gargoyle geckos cannot be sexed reliably as hatchlings. Sex becomes clear as they grow.

• The bulge is the dependable sign. It usually develops at about 18–25 grams [14]. Some breeders report sexing at about 15 grams [18] (hobby report).
• Pore checks can mislead. Looking for pores with a jeweler's loupe can give an earlier answer, but experienced keepers warn it is unreliable on small geckos [13][14]. Females can have false pores (0–3 rows in females versus 5–7 in males) [6], and young females can show a slight bulge that fools new keepers [13].

We recommend calling a gargoyle male or female only once the bulge is unmistakable, at roughly 20 grams or more. For a smaller juvenile, "unsexed" or "probable male/female" is the honest answer.

Maturity and breeding condition

Age and weight both matter. A heavy 12-month-old female is not the same as a mature 20-month-old female.

Sources vary a little on the female weight minimum. One university herpetarium says gargoyles reach maturity at around 40 grams, between 12 and 18 months [6]; one breeder care sheet gives 40 grams and 12 months for females, and 30 grams and 10 months for males [16]; a hobby care sheet gives 34 grams [18]; and a hobby breeding page says 40 grams minimum, with many breeders waiting until 50 grams and full maturity at 18–24 months [17]. One long-time breeder pairs males at about 1 year and says females usually finish maturing at about 18 months, "give or take a few months" [13].

We recommend not pairing a female under 40 grams or under 18 months old. Smaller, younger females lay smaller or infertile eggs, lose weight faster, and are at higher risk of a calcium crash. A full-grown adult usually weighs 60–70 grams [19], so a 40-gram female is still growing.

Pairing, and why you separate afterward

Gargoyle geckos are not social. Pair a male with a female only if you plan to breed, and never house two males together, because they fight and can seriously injure or kill each other [15]. Hatchlings and juveniles must also be housed apart to prevent injury [6].

Tail and toe biting is the species' trademark. Breeding males rarely keep their original tail, and regrown tails often get bitten off again once they are big enough [13]. Hatchlings kept together will eat each other's tails [18]. Toes and toe pads can also be bitten in scuffles. A lost tail regrows, usually smoother and plainer in color, but a bitten-off toe does not.

How to pair

1. Confirm both geckos are at breeding weight, healthy and of similar size. Avoid putting a small young male in with a much larger female [13][16].
2. Introduce the new gecko a few hours before lights-out at the far end of the enclosure, then leave them alone [16]. Most geckos will not mate while being watched [13].
3. Expect noise. Grumbling, chirps, squeals and the male nipping the female's sides, neck and tail are normal courtship, not a fight [13][16]. Mating takes seconds to minutes [16].
4. Check every day for bite marks, scratches, lost tails or weight loss. If you see any, separate them right away [15][16].
5. Leave the pair together for a few days (some breeders leave compatible pairs longer, or together year-round [13][16]), then separate them. We recommend separating, because pairs kept together are more likely to lose tails and toes [15]. A female can lay fertile clutches for months after one successful pairing, so there is no need to leave the male in.

Group sizes. One male to one or two females is standard, and pairs are reported to be more productive than trios or groups [18] (hobby report). Some high-volume breeders run one male with three females in large tubs [13], but that takes an experienced eye. For most keepers, one male with one female is the safe choice.

Enclosure for pairing: at least 18×18×24 in (46×46×61 cm) [16]. One major care guide sets the adult minimum at 18×18×36 in (46×46×91 cm) [15].

Cooling and rest periods

Gargoyle geckos do not need a cooling period to breed. One experienced breeder states that no special heating or cooling is required [13]. Many breeders still give one, because it tends to sync the female's cycle so the season starts predictably, and it gives both animals a rest. Typical practice, which is breeder experience rather than tested research:

• Length: 4–6 weeks before pairing [17], usually over the winter so the season can start around February in the Northern Hemisphere. One hobby care sheet uses a couple of months [18].
• Temperatures: days of 68–70°F (20–21°C) and nights of 64–66°F (18–19°C) [18], or simply nights in the low 60s°F (16–18°C) [17]. Do not go below about 60°F (15.5°C).
• Feeding: keep offering the powdered diet. Appetite drops naturally.
• Rest after the season: at least 4–6 months off before the next season. Some breeders breed each female only every other year [17]. Females can lose 15–25% of their body weight over a season and should regain their pre-breeding weight within 2–3 months of their last clutch before they are considered ready again [17].

We recommend giving every breeding female the whole winter off, every year.

The lay box

Females bury their eggs [13]. Without a lay box, a female may dig into the substrate, drop eggs in the water dish, or hold them, which risks egg-binding.

• Container: a lidded plastic box of about 6 quarts (5.7 L) with a hole cut in the lid [13], a reptile hide box, or a modified food container [16].
• Fill: 3–4 in (8–10 cm) of slightly moist coconut fiber, or a half-and-half mix of coconut fiber and fir bark [16]. It should hold its shape when squeezed but never drip.
• Placement: on the enclosure floor, out of the spray of any misting system [16]. In a planted bioactive enclosure, a layer of mesh under the substrate elsewhere can discourage laying outside the box [16].
• Check daily once the female is gravid. You can often see or feel the eggs as two lumps in her lower belly. Dig gently with your fingers, not tools.

Eggs and clutches

With a winter cool-down, the season runs roughly February through August in the Northern Hemisphere [17]. Females kept warm all year may lay on and off year-round, which is hard on them. A female paired once can keep laying fertile clutches for the whole season from stored sperm. Breeders widely report this, but no study has tested it in this species.

Eggs are soft-shelled and about the size of a jelly bean. Mark the top of each egg with a soft pencil when you lift it, and keep that side up [16]. Shining a small flashlight through the egg ("candling") can show a red bullseye of blood vessels in a fertile egg, but candling is not definitive, so incubate every egg anyway [16]. Remove an egg only once it is clearly bad: collapsed, yellowed and moldy.

Incubation

This is one of the easiest incubations in the hobby: room temperature, no added heat.

Why cooler is better. Cooler incubation takes longer but produces larger hatchlings that grow faster [13][17]. Breeders also report that warm incubation, above about 80°F (27°C), gives small, weak hatchlings and more deformities. This is breeder experience, not proven.

Does temperature set the sex? Sources disagree. One says the species has genetic sex determination and temperature does not change the ratio [17]. Another calls temperature-based sex determination "possible, but not carefully controlled" [6]. Treat it as unknown, and do not expect to incubate for a particular sex.

Equipment. A closet, basement shelf or wine cooler that holds a steady 72–76°F (22–24°C) is enough. If you use an incubator, choose a digital or pulse-proportional thermostat rather than a basic dial type [16]. A min/max thermometer in the room tells you whether summer heat spikes are a problem.

Hatching. A hatchling can take up to 24 hours from first slitting the shell to climbing out. Do not help it [17].

Hatchling care

• First shed. Leave the hatchling in its incubation cup or a small deli cup until its first shed, usually within 12–24 hours [16]. It will eat the shed skin.
• House singly. Hatchlings bite each other's tails and toes [6][18]. One major care guide sets 12×12×12 in (30×30×30 cm) as the minimum for one hatchling under 12 grams [15]; many breeders use a small tub of similar size.
• Setup. Use a paper towel floor until about 4–5 months old to reduce impaction risk [16]. Add a humid hide (a deli cup with damp sphagnum moss), a removable climbing structure of artificial plants or egg carton, and a hygrometer [13].
• Food. Offer a complete powdered gecko diet every other day: a dime- to nickel-sized blob on an upturned 1.5 oz (44 ml) deli cup lid [16]. Remove any food that gets stuck to their feet. Small gut-loaded insects (1/8–1/4 in, or 3–6 mm, crickets or dubia roaches) can start at 2–4 weeks, dusted with calcium.
• Misting. Mist lightly in the morning and generously at night [16]. Hatchlings dry out fast.
• What to expect. Hatchlings are about 1 in (25 mm) long and weigh about 3 grams [19]. A wavy or kinked tail in the first months is common and usually straightens. The skull "horns" develop with age [13].
• Handling. Let new hatchlings settle for at least a couple of weeks before regular handling [16].
• New homes. We recommend waiting until a baby has eaten the powdered diet reliably for at least 3–4 weeks and has gained weight before it goes to a new home. This is a hobby rule of thumb.

Protecting the female's calcium

Egg shells are built from the female's calcium. Gargoyle geckos store calcium in two sacs on the roof of the mouth, which show as white pads behind the upper jaw when the mouth is gently opened. Check these at least a couple of times a season. If they look shrunken or small, take the female out of breeding until they refill [16]. That guidance was written for crested geckos, but gargoyles have the same sacs.

1. Feed a complete powdered diet as the staple. It already contains calcium and D3.
2. Add calcium-dusted insects about twice a week during the season [6][18], and watch egg-laying females closely for early signs of calcium shortage [18].
3. Increase calcium right after a successful pairing, since egg development starts almost immediately [17].
4. Weigh weekly. Females can lose 15–25% of their weight over a season [17], so steady loss is a sign to slow down. Muscle tremors, twitching toes, tiredness, loss of appetite or seizures can mean a calcium crash. That is an emergency: stop breeding her, separate her, and get her to a reptile vet [17].
5. Rest her for the full off-season, and let her regain her pre-breeding weight before the next pairing [17].

How many babies to expect

These figures are for planning, not promises.

A single proven female realistically produces 6–11 hatchlings a year, and roughly 40–60 over a breeding life of about 6 years [6]. One male with two females can mean 12–22 hatchlings a year. Each one then needs 3–6 months of its own housing and feeding before it is ready for a new home, so count tub space and good homes, not just eggs.

Breeding checklist

1. Female 40 grams or more and at least 18 months old; male 30 grams or more, of similar size.
2. Both animals weighed, calcium sacs checked, and free of mites and parasites.
3. Separate enclosures ready for after pairing.
4. Lay box in place before pairing.
5. Incubation spot confirmed at 70–78°F (21–26°C) with a min/max thermometer.
6. Deli cups, incubation medium, a soft pencil and a hygrometer on hand.
7. Hatchling tubs and paper towel ready by about day 55.
8. Good homes lined up before the eggs hatch.

Wash your hands with soap and water after touching your gargoyle geckos, their eggs, their enclosures or anything in them. The CDC says children under 5 should not touch reptiles, and reptiles are not recommended for homes with children under 5, adults 65 and older, or people with weakened immune systems [8].