While reading, or in some cases re-reading, material it became apparent to us there are several specific islands in various publications as having an, as of yet, unidentified boa as an inhabitant.  Are they range extensions of known boas, new subspecies or species?  Here are the candidates as written about in the literature:

• C.s. fowleri:  Sheplan and Schwartz (1974) identify a museum specimen from Mangrove Cay in Central Andros.  Mangrove Cay lies between South Bight and Middle Bight; completely isolated from all other C.s. fowleri populations.  This Mangrove Cay specimen is a female with a SVL of 980 mm and is, dorsally, a patternless medium brown.  There is a blueish gray stripe that extends from the rear of the jaw to midbody.  The boa is basically patternless but for some small darker brown blotches below the lateral stripe and a few scattered dorsal black scales.  Since Central Andros and South Andros are both large land masses and completely separated from the east-west bight system, it is possible the boas separated from the boas on North Andros.  This specimen is either an aberrant color/pattern of the subspecies or something new.  More material from the Cay is needed to determine where this locale stands.   (p88-89)
•  C.f. fordii:  Sheplan & Schwartz (1974) lament the lack of specimens from different areas on the island and remark on the difficulty of assessing geographic variation with the species.  They feel collecting more specimens throughout the range of E. fordii will result in the species consisting of at least 3 populations.
•   C.f. fordii:  Schwartz writes of fordii in 1979 (p254), while describing C.f. manototus:  “There are also apparently isolated populations at Cap-Haitien on the northern Haitian coast and in the Valle de Cibao in northwestern Republica Dominicana; these two populations are questionably assigned to C.f. fordii.  A third isolate has been recently discovered on Isla Catalina by R.I. Crombie (pers. comm.).  That island is far (135 km) to the east of the previously easternmost locality record (Limonal) for the species.”
• C.s. strigilatus:  Sheplan & Schwartz (1974) write,”The species may occur on Green Cay on the eastern edge of the Tongue of the Ocean.  That isolated islet has a poorly known but remarkably diverse herpetofauna.”    Can it be found there?  If so, is it C.s. strigilatus, a subspecies or a new species?  (p80)
• C. chrysogaster:  Buden writes in 1975; There are unconfirmed reports of its existence on East Caicos, Providenciales and Pine Cay .  He also mentions the fact that Mayaguana, even though in line between the Caicos Bank and the Crooked-Acklins Bank, is devoid of the boa.  Though Mayaguana is similar in topography as the other two banks, it has but two lizards as inhabitants.
• C. chrysogaster:  In addition to Buden, in 1987 Tolson also depicts Mayaguana on a map and denotes the island with a question mark. Can C. chrysogaster be found there?

• C. exsul:  Sheplan and Schwartz opine in 1974, “Since there is only one specimen available from Little Abaco, it is impossible to compare the populations of E. exsul on Little and Great Abaco. However, the following data are of interest. The Little Abaco specimen (CM 45450) is the largest male exsul (the larger of the two Great Abaco males has a 525 mm snout-vent length), it has the only pre-intersupraocular scale count of 3 (all other snakes have 5 scales in this position), and has the only post-intersupraocular count of 3 (4 or 5 on Great Abaco). The Little Abaco male also sets the low parameters of anterior and posterior dorsal scale rows (28 on neck, 19 before vent). The scale differences between this snake and those from Great Abaco suggest that some differentiation has taken place.” (Sheplan & Schwartz, 1974).
• The question of E.s. versicolor has never been truly settled.  Sheplan and Schwartz remark:  “If at some future time the Bahamian snakes presently regarded as E. striatus strigilatus are subdivided, then versicolor will require further consideration.”
• A population of C. gracilis exists at the east side of the Barahona Peninsula in the south of the Dominican Republic. Sheplan and Schwartz examined four specimens from this population and noted that they were similar in size to the C. g. hapalus specimens, however the ventral counts of these snakes resembled closer those of C. g. gracilis. Thus Sheplan and Schwartz suggested that this population represents extreme intergrades between C. g. hapalus and C. g. gracilis. They noted that there are no specimens of C. g. hapalus closer than 150 kilometers to the west (Port-au-Prince, Diquini, Ca Ira) in Haiti, although apparently suitable habitat occurs abundantly between the eastern coast of the Peninsula de Barahona and the base of the Tiburon Peninsula . However, Tolson and Henderson, as well as Henderson and Powell assigned this population with a questionmark . It is to this day unclear if this population is a natural variation of C. g. hapalus, an intergrade form between the two subspecies or a third – yet undescribed – subspecies of C. gracilis.

If any of these lingering questions have been answered, we have found no evidence in the writings thus far.  Feel free to point out the reference that resolves one or more of the above.

Citations