One of the very often reported issues in male panther chameleons imported from Madagascar is that they simply do not want to mate. So, in the seek of getting new genetics and fresh blood in the breeding lines, the approach of getting wild-caught animals from the wild often fails.
And people try whatever to change it and sometimes they succeed and sometimes not. Noone knows really what is behind it...
As usually, the answer gives us the Mother Nature and not the captivity...
Let us look at the natural reproductive cycle of the panther chameleons in the NW madagascar (slightly modified in the whole range of F. pardalis).
They pair-bond at the onset of the rainy season on late November - beginning of December. Right after that, they mate.
Females lay their eggs few weeks after, in January and February, the eggs then need about 8 months to incubate and the hatchlings appear between October and December.
So, there is the answer:
The males are really mating in the wild in a short period of about a month or two, the rest of the year, they stay sexually inactive.
For the females, it is not necessary to mate again to eventually lay the second clutch, they store sperm.
They sometimes do, as it does makes sense for them only to lay eggs e.g. in february, rest a bit and lay second clutch not later than in april: the eggs would not have enough time to hatch later than in December if laid later.
What happens when we import them.
1. Males are sexually active only in about 10% of the time of the year. So, 90% of the time they stay sexually inactive... Therefore, it is logical that 90% of the males have no interest in mating when they are imported.
2. We import them almost always to the northern hemisphere with a reverse climatic sequence of cycles. And we import almost always adult specimens that have already established their cycles. So, we expose them to summertime (especially in outdoor keeping, but partly also indoor) when they should have wintertime and rest and produce sperm at rest and lower temperatures, that are necessary for male gametes: spermatozoids.
3. We try to get for breeding and commercial reasons as many clutches as possible and often expose themselves to captive conditions (at least in indoor keeping) that do not resemble natural cycles but simulate a permanent summer and rainy season. So, instead of staying sexually active for one or two months, we suggest them to mate all year around. But, when they should produce good quality sperm?
4. When importing them, they are caught, and then transported, not fed or fed not properly and got to Antananarivo, at about 1300m (4000ft) a.s.l. In a completely different (colder, moister) climate than they experience in their home mostly. The they are closed to tiny boxes and shipped for days in darkness.
So, this is why they do not want to breed. We confuse them totally. Millions of years of evolution we want to ignore and force them to do what we want them to...
No wonder that it does not work.
What is the way out of this?
Some of the issues we hardly can influence, as they are the pay-off of the importing and transferring them to the artificial conditions in captivity.
The only way is to try to restore their natural cycles after wild-caught imports, and, produce healthy offsprings that will accept the cycles in captivity, we provide to them.