Posted by:
RichardFHoyer
at Sat Jul 26 00:44:00 2003 [ Email Message ] [ Show All Posts by RichardFHoyer ]
Eric:
My specific and current goals were mentioned in the first two sentences. I have been trying to discover all I possibly can about the life history aspects of the species.
The current focus or goal deals with trying to shed more light
on the relationships between various boa populations--in other words, a study dealing with taxonomic issues.
Existing literature on the Rubber Boa was pretty skimpy when I began my involvement with the species in the early 1960's. You could go to a univerity library and become and expert in a few days. Most of the literature at that time dealt with taxonomic issues and what eventually became known about the biology of the species was contained in scientific notes or short articles. The situation is only slightly change at the present time.
In 1974 I published a description of the boa population here in W. Oregon from a sample of somewhat over 300 specimens. I documented sex ratios amongst three age classes, described dimorphic differences between the sexes, and touch on taxonomic issues by indicating that the then recognized subspecies of C. b. bottae and C. b. utahensis was unworkable within Oregon.
Most of the information was new.
As a science teacher and helping raise a family, although I continued to go afield and gather information, time was not available to organize data and prepare drafts for publication. In late 1990 I was asked to present a paper at a symposium in the Seattle area and the following year, the proceedings were published. My topic dealt with reproduction in the species detailing data acquired on hundreds of litters. The paper was poorly written but the data was solid!
The Southern Rubber Boa (C. b. umbratica) had been desribed by Klauber in 1943 based on only two specimens, one each from the San Jacinto and San Bernardino Mts. in S. Calif. Some authors discounted that designation while one author suggested that umbratica be elevated to the species level. Upon retirement, I proposed a study of the SRB in conjuction with Dr. Glenn Stewart of Cal. Poly, Pomona. Virtually nothing was known about that race of boa which in 1971 had been designated as "RARE" by the Calif. Dept. of F & G later changed to "Threatened" in 1984.
I undertook that specific field study to try and shed some light on the basic biology of that regional population of C. bottae. Two papers developed from that study which were published in 2000. Essentially all of the information in those papers was new including information on diet, reproduction, size,
predation, etc. For instance, the conventional published thought
on the function of the blunt tail of C. bottae was for use against predators. This view was held despite the fact that no study had ever been conducted or data presented toward support of that position. Information on the basic function of the blunt tail acquired since the late 1960's, and alluded to in the two papers published in 1974, was again shown in the SRB study that the major function of the blunt tail is involved in feeding behavior.
At the time our study began, there was only about 28 - 30 preserved specimens of the SRB in all collections, not really large enough to make many determinations with confidence. Hence, one of our goals was to increase the size of SRB sample. We did that and as a result, were able to establish beyond any reasonable doubt that the SRB population in the San Bernardino Mts. was a dwarf form of C. bottae.
Because the issue of subspeciation was unsettled, the second project for was to address that issue. This meant acquiring larger samples of the species from various regions in which there was little or no representation. That is the thrust of my present efforts.
In a sense, you are correct in that superficially, all rubber boas look pretty much alike. However, the species probably has the most variation in major scalation features of any native snake. The scalation is so variable that in the late 1800's and early 1900's, there were about 6-7 species of boa described in 3-4 different genera. It wasn't until about the 1920's that all species were then placed into a single species we now identify as C. bottae. I use this variation in scalation as a natural tagging method. Boas are unique in this regard so that this natural type of fingerprinting allows me to identify individual specimens one from another.
You have alot of company in not being able to describe differences as despite it large distribution, its secretive habits do not readily lend to finding large samples and thus the species has been largely ignored as a subject for research.
When Dr. Stewart sent me data on 19 preserved SRB specimens in 1973, I noticed that the lengths he provided of those 19 SRB specimens were all pretty small. In my reply, I remarked on this point wondering if the SRB was a dwarf race of rubber boa. As mentioned above, they are and since 1997, I have confirmed that this dwarf form of C. bottae occurs in most if not all of the isolated mt. ranges and peaks in S. Calif. From the current evidence, C. bottae in the rest of the species distribution in N. Am. is what I call the large morph. Beside this size difference, there are scalation difference between different populations in different regions, some of which I believe may turn out to be statiscally significant.
(Mr.) Richard F. Hoyer
[ Hide Replies ]
|
RE: Why 38 boas? - RichardFHoyer, Sat Jul 26 00:44:00 2003