By Jerry G. Walls
I've recently purchased my first breeding pair of Bibron's geckos (Pachydactylus bibroni). I'm looking for good basic information on conditioning them, their preferred breeding habitat, incubation period and how to raise the young. What do you recommend?
Kylene Burey
Ottawa, Ontario, Canada
Bibron's geckos are one of the familiar larger species, but it seems that little captive-breeding information is published on them. Perhaps this is because the species is almost always sold as wild-caught specimens at low prices, so there is little initiative to breed them and publish the results.
There also is a problem with the correct scientific name for this common thick-toed gecko. According to recent revisions, Pachydactylus bibroni is restricted to southern South Africa and is not exported at the moment. What is in the hobby now is said to be the virtually identical P. turneri, a name first used by Gray in 1864 and resurrected for the similar-looking thick-toed geckos found in Tanzania, Zimbabwe and areas south into northeastern South Africa. True bibroni have regular, dark-brown bands across the back, while in the terrarium form (probably turneri) they are broken and highly irregular in color.
Bibron's geckos thrive in warm, relatively dry terrariums. Though in nature nocturnal, most captives like to bask under a weak light and often stay out during the day. The sexes lack obvious external distinctions, such as femoral pores. Males are heavier in build, more aggressive and have an enlarged tail base caused by the hemipenes - the best way of sexing them.
I am not aware of any conditioning required to breed them, but a breeding colony consisting of a single male with two or three females is recommended. Feed them heavily on crickets and mealworms, and try to add some local grasshoppers or even an occasional pinky mouse to fatten up any females. The diet must be high in calcium so females can form proper eggshells.
In nature, these are colonial geckos that can be found by the dozen on rocky piles and in dry gardens. This does not mean that they are gentle geckos, and fighting does occur, sometimes with the loss of digits or torn skin. Warm room temperatures (70 to 85 degrees Fahrenheit) will suffice, especially if one corner of the terrarium is kept a bit warmer during the day. Allow the temperature to drop at night. Daily misting should provide sufficient humidity.
Mating takes place mostly at night and is not often seen. The female lays two half-inch, hard-shelled, rounded eggs in a clutch (young females may lay only a single egg), placing them in a relatively moist spot under a rock or a bit of bark. In nature, good laying spots are rare, so many females may lay in a single spot.
The eggs can be left in the terrarium or removed and incubated at about 80 to 82 degrees. There is some controversy about length of incubation, but 45 to 60 days will cover most of the range, with 55 to 60 days being typical.
Hatchlings are about 2 inches long, have more distinct patterns than adults and are little eating machines that take almost any insect that will fit in their mouths. Because of fighting, it's best to raise them separately or at least in small groups. Babies left in the terrarium with the adults probably are safe if there is lots of cover, but they could also turn into a snack. Conventional thought is that babies kept on sand may swallow too much of it with their insects, resulting in impactions. However, most keepers don't see it as a major concern. If you want to be safe, use wood chips for substrate.
Females may lay at least three to six clutches of eggs a year, so the babies just keep coming, and in about 18 months you could be breeding your second generation. These geckos can live at least six to eight years. Be patient and you are almost certain to get at least a few young.