Reptile & Amphibian Forums

Do the ranges of these ssp overlap, and if so, is there an effect on coloration or anything else?
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...and I think to myself, "What a wonderful world."

Shaky -- the quick answer is, yes, there are places in Mexico where the ranges of the two overlap. And I'd point to Southern Chihuahua and Northern Durango as one of those places. And, yes, where the ranges overlap there is interbreeding that places havoc with counting scales. However, with a species like deppei that has such a variable coloration anyway, would intergrades cause any problems? Probably not. Blotch counts would change, too. BTW, here are the ranges as I understand them right now, and as they are noted at my web site.

P. d. jani range: The Barlett's state "The more easterly of the two races of Mexican Bullsnake (P. d. janni [sic]) is found in the Mexican states of Coahuila, Nuevo Leon, Hidalgo, and Tamaulipas" ( 91).

Kardon gives a range of northcentral to western Mexico, to include the Sierra Madre Oriental (Snakeling 41).

P. d. deppei range: Alan Kardon states that deppei deppei ranges from "Chihuahua to Durango, Jalisco, Hidalgo, Colima, Veracruz, Mexico state, etc. in Sierra Madres at elevations ranging from 5,000 ft. to 8,000 ft" (forum post, August 27, 1997).

R.D. and Patricia P. Bartlett give the range for P. d. deppei as "the Sierran elevations in central northern Mexico" (Snakes 91).

Now I need to see current studies, if any, that are more definitive than that. Wish I could pin this answer down for you, but I know I am only in the ballpark.

Shannon

Shaky -- forget my comments about range overlap in S. Chihuahua and N. Durango. That's where deppei deppei, affinis, and sayi ranges overlap. Here's what Smith and Taylor in an old study say about deppei ranges:

Pituophis deppei deppei

Central Puebla through central San Luis Potosi to central Coahuila, westward to Jalisco and southern Chihuahua, eastward in the north to northern central Nuevo Leon (recorded in Mexico from the states of Aquascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Jalisco, Mexico, Michoacan, Nuevo Leon, Puebla, San Luis Potosi, and Veracruz, and Distrito Federal.

Pituophis deppei jani

Northern Hidalgo to southeastern Coahuila, on the interior arid slopes of the Sierra Madre Oriental (known from Buena Vista 30 miles west of La Rosa, Coahuila; Jacala and vicinity of Ixmiquilpan, Hidalgo; Galeana, Nuevo Leon; Miquihuana and Ranch Santa Ana, Tamaulipas).

From pages 107-108, Smithsonian Institution, United States National Museum, Bulletin 187, An Annotated Checklist and Key to the Snakes of Mexico, Hobart M. Smith and Edward H. Taylor, 1945.

So extrapolating from these ranges, it looks like they overlap in Tamaulipas, Neuvo Leon, and Coahuila. I'm sure new records indicate other range overlaps as well. I just don't have that info at hand.

Shannon

wondered their ranges and if they overlap. I appreciate it, thanks again.
Gregg F.
Gregg's RB