For many herpetologists and chameleon enthusiasts breeding panther chameleons is a highly rewarding extension of their interest in panther chameleon husbandry. While successful captive breeding of this species can initially be challenging, by gaining a good understanding of reproduction in panther chameleons, as well as acquiring all of the equipment required to facilitate each stage of the process, enthusiasts stand a good chance of breeding panther chameleons and raising hatchlings successfully.
Sexing Panther Chameleons
The first step in breeding panther chameleons is to acquire a compatible mating pair. Needless to say both the male and female should be in good health and should have been provided with a varied diet of suitable gutloaded feeder insects. Adult males are easily distinguished from adult females due to their larger size and the fact that they are much more colourful than females. Sexing young panther chameleons can be much more difficult however. Immature males can usually be distinguished from females by looking at the tail base. Even at the hatchling stage males tend to have a thicker tail base than females as the undeveloped pair of hemipenal pockets give the underside of the tail base a gently tapered slope. Young females lack the thickened tail base and tend to display more orange or pink on the body. Females also tend to have more red or orange on the interstitial skin of the gular region (throat) although this is not always the case. Using the above guidelines panther chameleons can be sexed with a relatively high degree of accuracy. When mistakes are made it is usually a case of males being misidentified as females as the hemipenal pockets are not always obvious to inexperienced chameleon enthusiasts.
Captive Panther Chameleon Courtship and Mating
While some herpetologists have experienced breeding success when permanently maintaining pairs or breeding groups consisting of a single male and several (up to 5) females, the most commonly used approach involves maintaining individual male and female adults in isolation, occasionally introducing one individual in to the enclosure of an adult of the opposite sex. This approach best reflects behavior observed in wild populations where males and females form breeding pairs but tend to be solitary and well spaced out when not breeding. As the technique involving permanent isolation of individual adults interspersed with periodical introduction of opposite sexed individuals for mating tends to be the most widely used approach and best replicates field observations, this technique will be the focus of the rest of this article.
The first step is to ensure that the adult female is in breeding condition. Females become receptive to the courtship advances of adult males spontaneously after reaching sexual maturity. Receptive females can be identified by the brightening of body colour and by the suppression of markings and body patterns. Females that have not bred in the past tend to remain receptive for up to 3 months, while non-virgin females that are denied the opportunity to mate assume non-receptivitiy rapidly, usually after just a few days. The breeding season for female panther chameleons varies between populations, with some populations showing very well defined short breeding seasons, while individuals from other populations are able to breed for most of the year. In addition the timing of receptivity to mating and the duration of gestation varies between individuals, although it is generally fairly predictable for a single known individual.
When deciding which individual (male or female) to introduce to the others enclosure it is important to keep in mind the temperament of each individual animal. Generally speaking the tamer individual should be chosen to be the introduced non-resident. If both animals are equally tame it isn’t so important which is introduced and which is resident. The process of introduction involves opening the enclosure door of the resident and displaying the individual of the opposite sex to them. This is commonly achieved by having the individual to be introduced perched on a stick or a hand in full view of the resident and watching for the social interaction to begin. If the male begins courting the female too aggressively the female may display non-receptive behaviour even if she is in breeding condition. In such cases the pair should be isolated from one another but still in view. Typically within a few hours the male will become used to the females presence and will approach with a less aggressive and more ritualised courtship display. If the females body colouration and suppression of markings (described above) persists after she has seen the male this indicates that she is receptive to mating.
The next step is to leave the pair cohabiting an enclosure for up to 2 weeks or until the female begins to display non-reciptive colouration and behaviour. Non-receptive females in the presence of males commonly flatten their bodies laterally, rock from side to side while gaping, and display dark colouration and bold patterns on the body. At this stage females should be isolated from males by returning the introduced individual back to its original enclosure.
Approximately 3 to 6 weeks after mating females start to noticeably become restless, which indicates that she will soon be ready to lay her eggs. Nesting substrate made up of moist potting soil and/or moist sand should be provided in a container at the bottom of her enclosure. It is important that the substrate provided is between 16cm and 30cm deep (approx 6in to 12in). Gravid females not provided with substrate to dig a nest in commonly oviposit (lay) their eggs on the floor of the enclosure where the eggs rapidly dehydrate and subsequently spoil. It is also possible that females not provided with suitable substrate will retain some eggs, leading to infection and death of the female. It is also important to prevent insect prey from roaming around the bottom of the enclosure at this time as them may disturb the female or try to predate the eggs.
Incubating Panther Chameleon Eggs
After laying her eggs (oviposition) in the container of substrate, the female will appear noticeably thinner and will often have some of the nest box substrate attached to her. At this point the eggs should be removed and placed in an incubation chamber. The incubation chamber should be filled with vermiculite and sealed (or at least partially sealed) to retain moisture. The vermiculite should be moist, with particles sticking together when squeezed but not dripping with excess water as this can cause egg bursting and death. A good rule of thumb is to mix (by weight) 1 part of medium grained vermiculite with 0.7 parts of water. The eggs should be spaced out within the moist vermiculite.
The duration of incubation rages from 6 months to 12 months depending on the temperature at which the eggs are incubated. Once laid, panther chameleon eggs remain in diapause for between 3 to 6 months before developing further. In the wild the cooler winter temperatures characteristic of Madagascar hold eggs in diapause before further development is initiated by rising spring temperatures. It is thought that this phenomenon has evolved so that eggs laid at different times hatch simultaneously when conditions are favourable for hatchlings. The duration of diapause (and incubation) is therefore strongly influenced by incubation temperature. For example, eggs incubated at a constant temperature of 28c (82f) will hatch approximately 2-6 months later than eggs incubated at 18c (65f ) for a month or two followed by fluctuating day/night temperatures of 18c/26c (approx. 65f/79f). This is because the cooler temperature followed by a slight increase in temperature mimic the transition of the seasons (winter to early spring), initiating further development by ending the diapause phase earlier (sometimes before 3 months), while a constant temperature of 28c (82f) prolongs diapause for several months before further development begins. It is important not to discard healthy eggs even if they have been incubating for an extremely long time as diapause can be prolonged even further if eggs are incubated at improper temperatures. Infertile and dead eggs are easily identified as they spoil just a week after either oviposition (infertile eggs) or death.
Panther chameleon eggs are relatively robust and can be gently handled when in diapause. The initiation of further development after diapause can be identified by holding the egg gently between finger and thumb and placing the egg between the observer and a suitable light source. Should the egg appear yellow this indicates that the egg is still in diapause, while pink indicates further embryonic development. After the end of diapause it is still possible to handle eggs carefully, although it is important not to change the orientation of the eggs.
Hatching Panther Chameleon Eggs and Hatchling Care
Just prior to hatching beads of moisture can be observed forming of the surface of the eggs as they become more permeable, and their size noticeably decreases. Within a few days the neonate inside the egg makes a slit in the shell before emerging a few days later. It is extremely important to prevent the eggs from becoming dry at this stage as the neonate may be unable to either create the slit or hatch out after having made the slit. For this reason some herpetologists recommend spraying the eggs with water or saline solution when the first signs of egg permeability are observed. Should the neonate fail to make a slit in the shell a few days after permeability is observed it will likely die, so some herpetologists also recommend manual slitting of the eggs, although this will likely be unnecessary in the majority of cases.
Panther chameleon hatchlings should be housed in small enclosures such as plastic or glass tanks or small screened enclosures. 1-2 gallon capacity containers are a suitable guideline in terms of size as this stage. The environmental (temperature, humidity, UVB lighting) requirements are the same as for adult panther chameleons. Neonates should also be provided with ample structures for climbing and perching as well as cover to hide in. A small container such as the lid of a jar should also be provided. This should contain 10-20 crickets of 1mm to 3mm in size at all times. Fruit flies are another good food source during the first few weeks and can be cultured relatively easily. Providing that feeder insects are gutloaded with a suitable diet it is not necessary to dust them, although some hepetologists recommend occasional dusting of a few individual crickets. As the young chameleons grow their enclosures and feeder insects should also increase in size as appropriate.