The Subspecies of Boa constrictor and their Varieties

The following description of the subspecies of Boa constrictor and their varieties occurring in their individual ranges mirrors the actual state of knowledge. Some classifications, however, are producing controversy. This has always been the case (not only for Boa constrictor), and will continue to be in the future.

We take the liberty of defending our personal point of view in controversial cases. Nevertheless, we will always hint at differing positions in the following paragraphs. Errors can never be excluded, and the taxonomic system is in permanent flow. Consequently, one or the other position statement found in this book may turn out to be erroneous or obsolete within a few years (a fairly good example for such a case is given in the chapter dealing with B. c. ortonii).  

At present, new classification of Boa constrictor is achieved by means of genetic analyses, and thus it may happen that some varieties of this species will be assigned to different subspecies, or that new subspecies must be defined for recognized forms.

Until Boa constrictor has been categorized genetically, taxonomists still make do with counting scales or saddle patches. We cannot deny that we do not share the general sympathy with these procedures. There is simply too little basic matter for comparison to achieve sound results – a situation which is also reflected by the fact that the opinions of the taxonomists concerning the ‘correct’ number of scales in this or that subspecies differ considerably. In addition, a crossbred boa may present the same number of scales as a pure-blooded one.

Although we maintain a critical position towards this kind of identification, we have nevertheless listed the number of scales, saddle patches, and ventral and dorsal shields found in the individual subspecies in order to achieve completeness.