Just like all other tortoises age is not a good way to determine if the tortoise can breed or not, measuring the tortoise would be a more accurate way of telling. I have seen a big difference between my yearling pancake tortoises there is a big size difference, a lot of factors can be the answer to faster growth such as food, humidity... January through march is the normal breeding season for them if you also want to increase fertility u may want to add another male but at the same time add 2 more females.
Thanks for the replies. I should have been more clear; what I meant is at what size can they produce viable eggs? I looked for adults for several months without success so I have decided to get some hatchlings and raise them myself. Hence me wondering when they will be big enough to produce eggs of their own.
As far as the winter cycling, I have read that people have had success with reducing the length of time they receive daylight during the winter. Can anyone vouch for this?
I dont really do any of that if they are captive bred they should be used to your one seasonal weather and make their best out of it. I live in Thailand so right after the rainy season when its hot they start breeding. Adult size for is about 15+ for females and bit smaller for males. What country do you live in?
Seasonal variation in the natural range of pancakes does NOT include a cool down. They use rock crevices to moderate their climate so they do best in a narrow range of temp and RH. Breeding and egg laying is timed so hatchlings are most likely to emerge at the beginning of a wet season (greater food abundance). In captivity females can lay an egg as often as every 28 to 30 days for as many a six eggs in one year. Some females produce two eggs each laying, the normal is one. When any particular female lays or does not is all over the calendar.
So in captivity, maintain a steady temp and RH year round, 1.1 groups are okay as long as the female has a few choices for a retreat to get away from the male. As stated a second male kept separately can be used to prompt either to mate after a short term introduction. Sometimes multiple males will get along , this is more likely when no females are present. Males can get caught up in constant fighting and stressing of each other. A good group size is 1.2 to 1.4. You can use males from one group to instigate breeding in both groups by putting one male in another enclosure for a few hours, then putting the visiting male back into his home group. Both males will be hoped up on tortoise testosterone for several hours - days.