I've only had concinnus(2.5 to 3.5 feet) and ordinoides(1.5-2 feet) give birth. The very least I've seen from concinnus was 23 not counting 3 stills. All were good feeders and appeared to be doing well. In spite of that, only 18 were left alive beyond the 6 month mark. I've never experienced newborn concinnus larger than 6 inches. On average, they were a bit smaller than that. I've always got a few stills, a few deformed that died in a day or two. I've never got slugs from any garter. If I did, she sneaked them out and ate them the second I turned my back. For litters 25 count and up, the number of problem feeders (most, but not all of those die) and sudden death increases but in spite of that, I've never had huge losses and the losses were proportional for the size of the litter.

On the other hand, I've never got more than 8 from an ordinoides. All were 4-6 inches. Never had stills, never had any suddenly die. Although there are few in number, they seem much larger and hardier than any concinnus litters I ever had and yet concinnus are much larger snakes as adults. Also, in spite of the size of the litters, concinnus aren't nearly as numberous as ordinoides in any given location. I think it's also interesting to note that even being there when they emerge from the dens, nearly all the snakes are the same size. Around 2 feet. The odds are against finding one larger or smaller.