Reptile & Amphibian Forums

Richard (or anyone else who knows),

I recently picked up a female RB that is supposedly cb and raised. They also claimed she is a yearling, but she is pretty large for a yearling, IMHO.
I am wondering if she is going to be big enough to try and breed next year. Do you have an approximate average mass for sexual maturity in females? Let's assume she isn't an umbratica, which I believe is a fair assumption.

TIA

Chris
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Chris Harrison

Chris,
Here at lower elevations in NW Oregon, females reach sexual maturity at about 22" and above. Without going back and searching my records, I believe I have had three local females slightly less than 22" that produced litters. For females of about 22" in reproductive condition, weights are usually around 75 grams to around 100 grams or a little more.

This past year I had a number of smaller females produce litters.
Four were from my E. Oregon study site at around 4600 ft. that is sagebrush / grassland habitat and 5 females from my study area in the mountains of SW Oregon at about 5200 ft. Females in these regions reach sexual maturity at smaller lengths than the boas at lower elevations. I just happened to have my folder with a summary sheet of those females showing lengths and weights at capture that can be used for comparison with your female boa.

Hyatt female #23 21 1/2" 77.0g (produced 3 neonates)
Hyatt female #26 22 1/4" 89.9g (produced 3 neonates)
Ft. Rock female #43 21 1/4" 54.9g (produced 2 neonates)
Ft. Rock female #42 21 3/8" 63.8g (produced 3 neonates)
Ft. Rock female #36 21 1/2" 61.5g (produced 2 neonates)

I also had two dwarf female C. bottae from S. Calif. that produced litters this past season.

Tehachapi female #3 21 1/2" 103.0g (produced 5 neonates)
Breckenridge female #5 18 1/2" 71.7g (produced 3 neonates)

And for added comparison, a female from Contra Costa County, Calif. near Berkeley is 27", weighted over 220 grams and produced a litter of 8 neonates. A local female over 28 inches was also over 200 grams and produced a litter of 7 neonates.

If you know the origin of the parents of your recent female Rubber Boa acquisition, perhaps the above can give you and idea if your female may be of reproductive length and weight for next spring. It should be noted that weight wise, the Fort Rock females were in marginal condition yet still produced litters.

In the early 1970's, I maintained some mutant juveniles at room temperature for about two years and tried to get them to feed as frequently as possible in order to get them to the size of sexual maturity as soon as possible. As I recall, the lone male reached maturity at about 2 years of age and was ready to court the following spring at 2 years 8 or 9 months of age. The two females took one and two years longer to reach sexual maturity at 3 and 4 years if age, mated the following spring and produced litters when 4 and 5 years of age.

In the wild, the minimum time males reach maturity is about 3 years and females at 5 years. The average time it takes the species to reach maturity has not been determined but I hazard a guess that it is somewhere around 5-8 years for males and 7 -10 years for females.

That some individuals have been able to get their captive specimens to feed at regular, short intervals throughout the year so that sexual maturity is reached sooner than what I produced is always a possibility. Doing so in one year seems out of reason from my experience and thus I am skeptical. But I learned long ago not to have a closed mind and thus leave the door open for such a possibility.

Richard F. Hoyer