at Tue Dec 25 13:07:35 2012 [ Report Abuse ] [ Email Message ] [ Show All Posts by RichardFHoyer ]
With respect to your reference to the SRB, that particular designation pertains only to populations of the species in the San Bernardino and San Jacinto Mts. Those two populations have been listed by the CDFG as 'Threatened' and thus are in a hands-off protected status.
Question #1: If the male you received measures 20 inches or greater (stretched length), it is highly unlikely to be a SRB. If its maximum dorsal scale row count is 43 or greater, then it is not a SRB. If the boa's ventral count is in excess of about 210, it is not likely to be a SRB. If the suture between the parietal and frontal head plates is moderately to strongly curved, it is highly unlikely to be a SRB. (Add details below).
Question #2: There is no problem with having specimens of different origins or subspecies being housed together.
Question #3: I believe I answered that inquiry in my response to your private email.
Richard F. Hoyer
Based on only two specimens, one from each of the San Jacinto and San Bernardino mountain ranges, in 1943, Lawrence Klauber proposed those two populations be assigned the subspecific status of Charina bottae umbratica, Southern Rubber Boa.
In 1971, the CDFG placed the SRB in a protected status officially claiming the subspecies to be "RARE". In the early 1980s, CDFG changed the status from 'RARE' to 'Threatened' to conform with federal terminology.
The primary distinguishing features of the SRB are as follows: They are a dwarf form of the Rubber Boa as shown by a study myself and Dr. Glenn Stewart undertook between 1993 and 1997. Recorded maximum lengths of adult males and females are about 19 1/2 inches and 22 1/4 inches respectively. Males above about 17 1/2 inches and female over 21 inches are uncommon. Most SRBs generally vary from light brown to tan dorsally and the ventrals are also a light shade of yellow. The maximum mid dorsal scale row count on the SRB is 42 however the vast majority of specimens have 41 or fewer dorsal scale rows. The suture between the frontal and parietal head plates tends to be flat or have less curvature than boas from other regions. Ventral counts are also lower than other populations.
There exists problems with the above features that once were defining traits of the SRB. That is, since the late 1990's, I have found that there are a number of other boa populations in S. Calif. that are of the dwarf phenotype. Most of those populations also are tan dorsally with light yellow ventrals. Although the other dwarf populations have somewhat higher mean dorsal scale row counts, higher mean ventral counts, and on the average have somewhat more curvature to the parietal / frontal suture, there exists considerable overlap in those traits between the SRB and these other dwarf boa populations. For instance, last year I determined that 38% of the sample of boas I had examined from Mt. Pinos (west of I-5 and Frazier Park, CA.) would key out to be SRBs using the combination of the above defining SRB features.
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