"The female will be ready in 07. The male will not be ready until 08. I do not want to risk the female retaining sperm or ruining the planned pairing in 08, so I will not breed her in 07 at all. However, I might be able to get the male up to size enough to try for a breeding with her late 07."
With my experience males tend to be more reliable being bred at a smaller size. If you think about it the female has to have the fat reserves for producing eggs and then use up reseves such as calcium. All the male has to do is deposit his sperm.
What I do not understand is why you are risking the female with retained sperm unless you are using a different male the folowing season(?)Not sure what you meant by that?
If you want to breed the female but are concerned about her size try this.
I put the females down late (late Jan) and feed them while they have the opportunity to thermoregulate (slight warm side).This gives more time to feed the females and giving them a chance to grow. Then I put the male in when the weather changes outside, usually late April here, no earlier. I do this so that the season outdoors correlates with what the snake is experiencing indoors. I hate artificial brumation where people warm the snakes in mid febuary and then go all the way till April for them to breed...nonsense. I go by what the season is doing naturally. If the snakes stay cool during march and april and I do not feed them, I don't sweat it (patience is a big aspect). Then I try and feed the female once or maybe not at all and put the male in with her and leave them together for some time.
I never worry about males being slim or small during spring or the summer. They do not have to carry the "*weight*" that the females do. What I do try to do is powerfeed the males and females as much as poissible with regard to the target breeding date late winter. In other words, if you think they can make size then feed as much as they will eat and as often as they will eat and keep them up as long as you think.
You can put down snakes late in the winter and bring them up with limited cool time and be successful. I used to breed rosy boas and put them down in June (in an ice chest) for two weeks and they would cycle. Seems weird but it worked for rosys. Agian with colubrids, I would not worry about the males. They don't need to be big. Focus on powerfeeding ( Gosh, I hate that word) the females more then males. The males will do their thing irregardless. Some are individuals in puberty...so don't take this as a science. Just individual males tend to either be small and horny and others are immature. Its a crap shoot. You will get the "green thumb"!
