Eastern Patch-nosed Snake (Salvadora grahamiae)

An Annotated Bibliography of the Eastern Patch-nosed Snake
(Salvadora grahamiae)

Compiled by Tom Lott [TEL] - Last updated on 22 September 2016

[These bibliographies and their annotations are an on-going project. I have many comments on papers that I have not yet posted but I will attempt to attend to this task as time allows. Comments proffered in the annotations are strictly my own opinions and should be taken as such. If you wish to comment or supply additional references that I have overlooked, you may contact me via E-mail. To correspond with me, I may be reached at:  tomlott[at]thornscrub[dot]com.  Thanks for reading, Tom Lott ]

Anderson, P.K. 1942.  New record for Salvadora lineata. Copeia 1942: 127.

Axtell, R. W. 1959b. Amphibians and reptiles of the Black Gap Wildlife Management Area, Brewster County, Texas. Southwest. Nat. 4(2): 88-109.  ["Three (1♂, 2♀) mountain patch-nosed snakes were secured, two from limestone gravel hills and one from the basalt talus slope.
              "Brown (1950:178) writes that'Salvadora hexalepis deserticola is a snake inhabiting the dry lowland areas of western Texas while S. grahamiae is to be found on the upper slopes of the mountains.'  We found both S. grahamiae and S. h. deserticola in our area, where local relief was at best no more than five to seven hundred feet.  One specimen of deserticola came from about 200 yards south of Dell Tank where a U.S.G.S. benchmark read 2,069 feet, while an S. grahamiae was found on a hillside approximately 500 yards southeast of Dell Tank where the elevation was not 300 feet higher.  From the few recordings it appears that grahamiae may prefer the rougher rocky slopes, while deserticola inhabits the less rugged floodplain and adjacent flat areas." - TEL]

________.  1977(1978).  Ancient playas and their influence on the recent herpetofauna of the northern Chihuahuan desert. In Transactions of the symposium on the biological resources of the Chihuahuan desert region, United States and Mexico. Ed. R.W. Wauer and D.H. Riskind, Ser. 3: 493-512.  Alpine, Tex.: National Park Service.

Baker, R.J., Mengden, G.A., and J.J. Bull. 1972.  Karyotypic studies of thirty-eight species of North American snakes.  Copeia 1972(2): 257-265. 

Blair, W.F. 1949. The biotic provinces of Texas. Texas J. Sci. 2(1):93-117.

________. 1953. Growth, dispersal and age of sexual maturity of the Mexican toad (Bufo valliceps Weigmann)> Copeia 1953: 208-212.

________. 1960d. The rusty lizard: a population study. Austin: University of Texas Press.

Bogert, C.M. 1939. Notes on snakes of the genus Salvadora with a redescription of a neglected Mexican subspecies. Copeia 1939: 140-147.

_________. 1939. A study of the genus Salvadora, the patch-nosed snakes.  Publ. Biol. Sci., Univ. Calif. Los Angeles 1: 177-236.

Boulenger, E.G. 1896.  Catalogue of the snakes in the British Museum, vol. 1.  London: Taylor and Francis

Boundy, J.  1997.  Maximum lengths of North American Snakes.  Bull. Chicago Herpetol. Soc. 29(6): 109-122.
[Cites the maximum length of the nominate subspecies as 953 mm (37.5 in., fide Conant 1975) and as 1194 mm (47.0 in., fide Conant 1958) for S. g. lineata.  - TEL]

Brattstrom, B.H. 1967. A succession of Pliocene and Pleistocene snake faunas from the High Plains of the United States.  Copeia 1967: 188-202.

Brennan, J.N. 1945.  Field investigations pertinent to Bullis fever: Preliminary report on the species of ticks and vertebrates occurring at Camp Bullis, Texas.  Texas Rept. Biol. Med. 3: 112-121. 

Brown, A.E. 1901a.  A review of the genera and species of American snakes north of Mexico.  Proc. Acad. Nat. Sci. Phila.  53:10-110.

_________. 1903b.  Texas reptiles and their faunal relations.  Proc. Acad. Nat. Sci. Phila.  55:543-558.

Brown, B. C. 1950. An annotated check list of the reptiles and amphibians of Texas. Waco: Baylor University Studies. 

Burchfield, P.M., T.F. Beimler, and C.S. Doucette. 1982.  An unusual precoital head-biting behavior in the Texas patchnosed snake, Salvadora grahamiae lineata (Reptilia: Serpentes: Colubridae). Copeia 1982: 192-193.  [On two occasions in mid-April of 1977, a sexual pair of this species captured at the same location exhibited mating behavior in captivity that was unusual.  First, the female of the pair was already gravid, but allowed copulation (the female laid nine eggs the following day, the timing of which is fairly normal for this species in south Texas).  Second, on each occasion the male grasped the head of the female in a manner that differed from the well-known neck-biting actions characteristic of many colubrids (other than the head biting, the copulatory behavior followed the typical colubrid pattern).  This head grasping behavior, however, was more consistent with that seen in a cannibalistic attack than in typical precoital ritual and continued throughout the copulations.  It would appear that this conduct, if indeed pervasive in this species, could easily be mistaken for a cannibalistic attack. - TEL]

Butterfield, B.P., S.E. Trauth, T.W. Steward, V.R. McDaniel, and P. McLarty. 1991. New county records of amphibians and reptiles from Texas.  Herpetol. Rev. 22: 28  [Eastland County record. - TEL]

Camper, J.D. and B.G. Hanks. 1995. Variation in the nucleolus organizer region among New World snakes.  J. Herpetol. 29: 468-471.

Carl, G. 1980.  Distributional records for Johnson County, Texas.  Herpetol. Rev. 11: 116-117.  [Johnson County record. - TEL]

Cochran, D.M. 1961.  Type specimens of reptiles and amphibians in the United States National Museum.  Bull. U.S. Natl. Mus. 220: 1-291.

Conant, R. 1942.  Notes on the young of three recently described snakes, with comments upon their relationships.  Bull. Chic. Acad. Sci. 6: 193-200.

_______ . 1958. A field guide to reptiles and amphibians of the United States and Canada east of the 100^th meridian. Boston: Houghton Mifflin Co.

_______ . 1975. A field guide to the reptiles and amphibians: Eastern and central North America. 2^nd edition. Boston: Houghton Mifflin Co.

_______ . and J. T. Collins. 1991. A field guide to the reptiles and amphibians: Eastern and central North America. Boston: Houghton Mifflin Co.

_______ . and ______. 1998. A field guide to the reptiles and amphibians: Eastern and central North America. 3^rd edition (expanded) Boston: Houghton Mifflin Co.

Cope, E. D. 1900. The crocodilians, lizards, and snakes of North America. Annu. Rept. U.S. Natl. Mus. 1898: 155-1294.

Cox, C.L., C.E. Roelke, and B. Pope. 2008.  Geographic distribution.  Salvadora grahamiae lineata (Texas patch-nosed snake).  Herpetol. Rev. 39: 373.  [Shackleford County record, from Hwy. 351 ca. 4.8 km S jct. with Hwy. 180. - TEL]

Davenport, J.W. 1943. Field book of the snakes of Bexar County, Texas, and vicinity.  San Antonio: Witte Memorial Museum.  Out of Print.

Degenhardt, W.G., Painter, C.W. and A. H. Price 1996. Amphibians and reptiles of New Mexico. Univ. New Mexico Press, 431 pp.

Desantis, D.L.; V. Mata-Silva, and J. D. Johnson. 2016.  Natural History Notes. Winter foraging.  Herpetol Rev. 47(3)483-484.  [A large adult male of the nominate subspecies (92.4 cm/36.4 in TTL) was found basking on 11 December 2015 on the Indio Mountains Research Station, Hudspeth Co., Texas.  This was during an unseasonably warm day (ambient temp.= 24.4^oC/75.9^oF).  The snake was also determined to contain a recently ingested meal (speculated to be a lizard, possibly Cophosaurus texana, although none were observed active in the area).  The authors could find no reports of winter feeding in this species, but noted that winter activity was common, having been observed during every month of the year except January at that locality.  They infer from this incident that this species may be an opportunistic winter feeder throughout the year, "given appropriate environmental conditions." - TEL]

Dixon, J. R. 1987. Amphibians and reptiles of Texas. W. L. Moody, Jr., Nat. Hist. Ser. 8. College Station: Texas A&M University Press.

_______ . 1993. Supplement to the literature for the Amphibians and reptiles of Texas. 1987. Smithson. Herpetol. Info. Serv. 94: 1-43.

_______ . 2000. Amphibians and reptiles of Texas. 2^nd Ed. W. L. Moody, Jr., Nat. Hist. Ser. 25. College Station: Texas A&M University Press.  [Provides 90 literature citations for this species.  Notes that D. L. Lannutti is tudying the systematics of the species at UTEP.  A county-based distribution map is provided. - TEL]

_______ . 2013. Amphibians and reptiles of Texas. 3rd Ed. W. L. Moody, Jr., Nat. Hist. Ser. 25. College Station: Texas A&M University Press.  [Provides 93 literature citations for the species.  Color photos of the nominate subspecies from Presidio County and S. g. lineata from Edwards County are provided.  A county-based distribution map is included.  Remarks are unchanged from the 2000 edition. I have reviewed this book HERE. - TEL]

_______ . and J.E. Werler.  2005.   Texas Snakes: A Field Guide.  Austin: University of Texas Press.  

Dunham, A.E. 1981.  Populations in a fluctuating environment: The comparative population ecology of the iguanid lizards Sceloporus merriami and Urosaurus ornatus.  Univ. Mich. Publ. Mus. Zool.  158: 1-62.

Ernst, C.H. and E.M. Ernst. 2003.  Snakes of the United States and Canada.  Washington and London: Smithsonian Books.

Gloyd, H.K. 1944.  Texas snakes.  Tex. Geogr. 8: 1-18. 

Gutberlet, R.L., C.L. Stewart, and M.B. Keck. 1998.  New distributional records for Texas reptiles and amphibians. Southwest. Nat. 43: 6-12.  [Karnes County record, FM 99 Coy City. - TEL]

Hampton, N. 1976. Annotated checklist of the amphibians and reptiles of Travis County, Texas. In A bird finding and naturalist's guide for Austin, Texas, area. ed E. Kutac and S. Caran, 84-101. Austin: Oasis Press.

Hartweg, H. 1940. Description of Salvadora intermedia, new species, with remarks on the grahamiae group.  Copeia 1940: 256-259.

Husack, J.F. and J. Wright. 1998b.  Geographic distribution. Salvadora grahamiae lineata.  Herpetol. Rev. 29: 116.  [Tom Green County record - TEL]

Jameson, D.L. and A.G. Flury. 1949.  Reptiles and amphibians of the Sierra Vieja.  Tex. J. Sci. 1(2): 54-79.

Karges, J.P. 1979.  Texas amphibians and reptiles: Some new distributional records. Part II. Herpetol. Rev. 10: 119-121.  [Dimmit, Duval, and Maverick county records. - TEL]

__________. 1981.  Texas amphibians and reptiles: Some new distributional records. Part III. Herpetol. Rev. 12(2): 68-69.  [Jim Hogg County record, 1.6 km NE Hebbronville. - TEL]

__________. 1982.  Texas amphibians and reptiles: Some new distributional records. Part IV. Herpetol. Rev. 13: 27.  [Zapata County record, on US 83, 9.7 km N San Ygnacio. - TEL]

Landwer, A.J. and T.E. Lee. 2001f.  Geographic distribution. Salvadora grahamiae (Texas patchnose snake).  Herpetol. Rev. 32: 124.  [Taylor County record, from 1.6 km N Lake Abilene. - TEL]

Licht, L.E. 1968.  Unpalatability and toxicity of toad eggs. Herpetologica 24: 93-98.  ["Tests with snakes were designed to observe the effects of ovarian eggs when ingested. Several hundred ovarian eggs were freeze-dried to a fine powder, placed in gelatin capsules . . ., and force fed to the snakes...
              "A Salvadora lineata (female, 24.4 g) was given .10 g of dried egg, and an Opheodrys aestivus (female, 42 g) was given .12 g of egg.  Both snakes are nontoad-eaters.  Two Thamnophis sirtalis, toad eaters, were also fed dried ovarian egg.  One (female, 21.5 g) was given .11 g of egg; the second (female, 51.2 g)was given .10 g of egg.
              "The Salvadora began opening and closing its mouth about 40 min after egg ingestion.  It then began rolling over continually onto its back, with its mouth open.  It would remain quiescent for 5-10 min, and begin rolling again.  The mouth continually opened and closed.  Three hours and 55 min after egg ingestion, final pronounced muscular tetany from snout to vent was culminated by death.
              "The same sequence of symptoms was observed in the Opheodrys which died in 5 hours and 15 min.
              "Neither of theT. sirtalis showed any ill effects and both and both appeared normal and fed one month later." - TEL]

________ and B. Low. 1968.  Cardiac response of snakes after ingestion of toad parotoid venom.  Copeia 1968: 547-551.

Logan, L.E., and C.C. Black. 1979.  The Quaternary vertebrate fauna of Upper Sloth Cave, Guadalupe Mountains National Park, Texas.  Natl. Parks Serv. Trans. Proc. Ser. 4: 141-158.

Marx, H. 1958.  Catalogue of type specimens of reptiles and amphibians in the Chicago Natural History Museum.  Fieldiana Zool. 36: 411-496.

Maxwell, T.C. 2013. Wildlife of the Concho Valley.  College Station: Texas A&M Univ. Press. 292 pp.  [Listed as "rare in southeastern and southern counties" of the Concho Basin but speculated that this impression may be due more to difficulty in catching fast-moving snakes than to actual scarcity - this is doubtful given that large numbers may be found under surface cover.  Maxwell could find only 5 museum specimens from the Basin, one each from Concho, Crockett, and Schleicher counties and two from Menard County - TEL]

McAllister, C.T., M.C. Wooten, and T.L. King. 1981.  Geographic distribution.  Salvadora grahamiae lineata.  Herpetol. Rev. 12(2): 66.  [Llano County record, 13.4 kn S Llano, off TX 16. - TEL]

 Mecham, J. S. 1979. The biogeographical relationships of the amphibians and reptiles of the Guadalupe Mountains. Nat. Park Serv. Trans. Proc. Ser. 4: 169-79.

Milstead, W.W., J.S. Meacham, and H. McClintock. 1950. The amphibians and reptiles of the Stockton Plateau in northern Terrell County, Texas. Tex. J. Sci. 2(4): 543-562.  ["Two specimens were collected on the Blackstone Ranch.  One was from the cedar-savannah and one was from the cedar-ocotillo association.  Blair collected an additional specimen in May from the cedar-ocotillo association near Gravel Springs.  This animal, a female, laid nine eggs soon after capture, and two of these were hatched in the laboratory during the summer." - TEL]

Minton, S.A. 1958(1959).  Observations on amphibians and reptiles of the Big Bend region of Texas.  Southwest. Nat. 3: 28-54. [Described S. grahamiae as being "largely restricted to the foothills and mesas from about 3300 to 5500 feet."  Usually seen on "mild, sunny mornings," his earliest specimen was found on 26 February.  He also describes them as quick to escape in brushy cover, but tending to freeze on road surfaces.  A female collected on 1 April deposited 6 eggs on 29 May.  Three of these eggs hatched on 27-28 August, with the young measuring 263, 264, and 267 mm, and strongly resembling adults in pattern and coloration. - TEL]

Morafka, D.J. 1977. A biogeographical analysis of the Chihuahuan desert through its herpetofauna. Biogeographica 9: 1-313.

___________. 1977 (1978).  Is there a Chihuahuan Desert? A quantitative evaluation through a herpetofauna perspective.  In Transactions of the symposium on the biological resources of the Chihuahuan desert region, United States and Mexico. Eds. R.W. Wauer and D.H. Riskind, Ser. 3: 437-454.  Alpine, Tex.: National Park Service.

Mosaur, W. 1932.  The amphibians and reptiles of the Guadalupe Mountains of New Mexico and Texas.  Occas. Pap. Mus. Zool. Univ. Mich. 246: 1-18.

Owen, J. G. 1989. Patterns of herpetofaunal species richness: Relation to temperature, precipitation, and variance in elevation. J. Biogeogr. 16: 141-50.

________ and J. R. Dixon. 1989. An ecogeographic analysis of the herpetofauna of Texas. Southwest. Nat. 34(2): 165-80.

Porter, Stuart T. 1969. An ecological survey of the herpetofauna of Palo Pinto County, Texas.  M.S. Thesis, North Texas State Univ. Pp. 1-55.  ["None of these were collected, but records from Conant (1942) and from specimens examined from the museums at North Texas State University (Denton, Texas) and Texas A. and M. University (College Station, Texas) indicate the presence of this snake in both the Oak Association and the Mesquite-Prairie Association. The Texas patch-nosed snake has a western distribution, but reaches its northeastern limit in Palo Pinto County." - TEL]

Ramirez-Bautista, A., X. Hernandez-Ibarra, and R. Torres-Cervantes. 2000. Natural history notes: Salvadora grahamiae lineata (Texas Patch-nosed Snake). Diet. Herpetol. Rev. 31(3): 180.  [A 5 g, 45 mm SVL partially digested Sceloporus s. scalaris was removed from the stomach of a 573 mm specimen of this species taken on the road between Las Lagunas and La Noria de las Flores, San Luis Potosi. - TEL]

Ramsey, L.W. 1951.  New localities for several Texas snakes. Herpetologica 7: 176.

Raun, G.G. 1959.  Terrestrial and aquatic vertebrates of a moist, relict area in Central Texas.  Tex. J. Sci. 14: 3-6.
[The author considered this species to be a western form near the eastern limits of its distribution in the vicinity of the relictual moist area partially contained within the Palmetto State Park, Gonzales County, Texas.  It was confined to the Post Oak-Blackjack vegetational community. - TEL]

_________. 1965b. A Guide to Texas Snakes. Tex. Mem. Mus. Notes 9.  [Account consists of a very brief sketch of the three forms of Salvadora found in Texas.  Includes a key to the forms, a black-and-white photo of S. g. lineata, a vague description of the range, food, habitat, and reproduction of each, as well as a notation of which of Blair's (1950) biotic provinces of Texas the form may be found. Not a particularly helpful reference. - TEL]

_________. 1966b. A population of woodrats (Neotoma micropus) in southern Texas.  Bull. Tex. Mem. Mus. 11 [Listed as a "presumed" predator of N. micropus, but such would be possible, given the size differential, only on newborn rat pups. - TEL]

_________.  and F.R. Gehlbach. 1972.  Amphibians and reptiles in Texas. Dallas Mus. Nat. Hist. Bull. 2: 1-61.

Rosen, P.C. 2005.  Lowland riparian herpetofaunas: The San Pedro River in southeastern Arizona.  USDA Forest Ser. Proc. Pp. 106-111.  [A survey of museum records from areas within two miles of the riparian bottomland of the river  yielded no Salvadora grahamiae, but it was listed as "expected" to occur in the "upper basin in Mexico, which has not been extensively surveyed."  Nine specimens of S. hexalepis, however, were found to be vouchered from the entire US reach of the river. - TEL]

Schmidt, K.P. 1940.  Notes on Texas snakes of the genus Salvadora.  Field Mus. Nat. Hist. Zool. Ser. 24: 143-150.
[The original description of this taxon as a full species, based upon a specimen from Kingsville, Texas.  In hindsight it seems remarkable that Schmidt, in this same paper, described S. deserticola as a subspecies of S. hexalepis, but failed to notice the substantial resemblance between his S. lineata and S. grahamiae - TEL]

_________. 1953. A checklist of North American amphibians and reptiles. Chicago: Univ. of Chicago Press.

_________. and D.D. Davis. 1941.  Field book of snakes of the United States and Canada.  New York: G.P. Putnam's Sons.

_________. and T.F. Smith. 1944.  Amphibians and reptiles of the Big Bend region of Texas.  Field Mus. Nat. Hist. Zool. Ser. 29:75-96  ["Two specimens from the Basin, collected by the writers in 1937, were discussed by the senior author in his description of the east Texan Salvadora lineata. The Chisos population of grahamiae is

widely isolated from that of southern Arizona, and affords a taxonomic problem for further study." - TEL]

Seifert, W. 1978d.  Geographic distribution.  Salvadora grahamiae lineata.  Herpetol Rev. 9(2): 62.  [Robertson County record, 4.8 km S Franklin. - TEL]

Smith, H.M. 1938d. Notes on the snakes of the genus Salvadora.  Univ. Kans. Sci. Bull. 25: 229-237.

_________.  and H. K. Buechner. 1947. The influence of the Balcones Escarpment on the distribution of amphibians and reptiles in Texas. Bull. Chi. Acad. Sci. 8(1): 1-16.

_________ and D. Chiszar. 1997. New records for amphibians and reptiles from Texas.  Herpetol. Rev. 28: 99-100.  [Willacy County record, 6.3 km E Porfirio. - TEL]

_________, P.A. Langbartel, and K.L. Williams. 1964. Type-specimens in the University of Illinois Museum of Natural History. III.  Biol. Monogr. 32: 1-80.

_________ and O. Sanders. 1952a.  Distributional data on Texas amphibians and reptiles.  Tex. J. Sci. 4: 204-219.

_________. and E.H. Taylor. 1945. An annotated checklist and key to the snakes of Mexico. Bull. U.S. Natl. Mus. 187:1-239.

________. 1950a.  Type localities of Mexican reptiles and amphibians.  Univ. Kans. Sci. Bull. 33:313-379.

Stallcup, W.B. 1961.  Notes on the vertebrate collection in the Department of Biology, Southern Methodist University.  J. Grad. Res. Ctr. 29: 66-69.

Stebbins, R. C. 1954. Amphibians and reptiles of western North America.  New York: McGraw-Hill.

____________. 1966. A field guide to western reptiles and amphibians. Boston: Houghton Mifflin Co.

Stone, W. 1903.  A collection of reptiles and batrachians from Arkansas, Indian Territory, and western Texas.  Proc. Acad. Nat. Sci. Phila. 55: 538-542.

__________. 1911.  On some collections of reptiles and batrachians from the western United States.  Proc. Acad. Nat. Sci. Phila. 63: 222-232.

Strecker, J.K. 1908a. The reptiles and batrachians of Victoria and Refugio counties, Texas.  Proc. Biol. Soc. Wash. 21: 47-52.

____________. 1908c. The reptiles and batrachians of McLennan County, Texas.  Proc. Biol. Soc. Wash. 21: 69-84.

____________. 1926d.  A list of reptiles and amphibians collected by Louis Garni in the vicinity of Boerne, Texas.  Contr. Baylor Univ. Mus. 6: 3-9.

____________. 1928e.  Common English and folk names for Texas amphibians and reptiles.  Contr. Baylor Univ. Mus. 16:1-21.

____________. 1930. A catalogue of the amphibians and reptiles of Travis County, Texas. Contr. Baylor Univ. Mus. 23: 1-16.

____________. 1935f.  The reptiles of West Frio Canyon, Real County, Texas.  Baylor Univ. Bull. 38:32.

____________ and J.E. Johnson. 1935. Notes on the herpetology of Wilson County, Texas. Baylor Univ. Bull. 38:17-23.

____________ and W.J. Williams. 1927. Herpetological records from the vicinity of San Marcos, Texas, with distributional data on the amphibians and reptiles of the Edwards Plateau region and Central Texas. Contr. Baylor Univ. Mus. 12: 1-16.

Swanson, R. L.  2009.  Temporal and spatial trends of the amphibians, reptiles, and mammals of the relict Ottine Wetlands.  MS Thesis, Texas State Univ. 83 pp.  [Swanson failed to find this species during a 16-month study, while Raun (1959) found one specimen during a 10-month study fifty years earlier, further supporting the contention that it is at the eastern limit of its distribution in this area.  This taxon is generally common where it occurs. - TEL]

Taggart, T.W., K.J. Irwin, and A. Sweetman. 1994.  Geographic distribution. Salvadora grahamiae.  Herpetol. Rev. 25: 77. [Hamilton County record, just SE of the jct. of Rt. 281 and the Bosque River. - TEL]

Tennant, A. 1984. The snakes of Texas. Austin: Texas Monthly Press.

__________. 1985. A field guide to Texas snakes. Austin: Texas Monthly Press.

__________. 1998. A field guide to Texas snakes. 2^nd edition. Houston: Gulf Publishing.

__________. and Bartlett, R.D. 2000. Snakes of North America - Eastern and Central Regions. Gulf Publishing, Houston, TX, 588 pp.

Turner, D.S., P.A. Holm, E.B. Wirt, and C.R. Schwalbe 2003.  Amphibians and reptiles of the Whetstone Mountains, Arizona.  Southwest. Nat. 48(3): 347-355.  [Study documented the presence of both Salvadora grahamiae and S. hexalepis in the range.  The latter was found in Madrean Woodland during the summer and in Semidesert Grassland during the spring.  Habitat of  S. grahamiae was not mentioned. - TEL]

Upton, S.J. and C.T. McAllister. 1990.  The Eimeria (Apicomplexa: Eimeriidae) of Serpentes, with descriptions of three new species from colubrid snakes.  Can. J. Zool. 68: 855-864.

Vermersch, T.G. and R.E. Kuntz. 1986. Snakes of South Central Texas. Eakin Press, Austin, Texas.

Ward, R., E.G. Zimmerman and T.L. King. 1990.  Multivariate analyses of terrestrial reptile distribution in Texas: An alternate view.  Southwest. Nat. 35:441-445.

Wauer, R.H. 1980.  Naturalist's Big Bend. An introduction to the trees and shrubs, wildflowers, cacti, mammals, birds, reptiles and amphibians, fish and insects.  College Station: TexasA&M University Press.

Werler, J.E., and J.R. Dixon. 2000. Texas Snakes. Identification, distribution, and natural history.  Austin: University of Texas Press. 

Worthington, R.D. 1976.  Herpetofauna of the Franklin Mountains, El Paso County, Texas.  In El Paso Geological Society symposium on the Franklin Mountains, ed. D.V. Lemone and E.M.P. Lovejoy, 205-212.  El Paso:
El Paso Geological Society Quinn Memorial Volume.  [Simply stated that the status of populations of this species in the Franklin Mountains was not known - TEL]

Wright, A. H., and A. A. Wright. 1952. List of the snakes of the United States and Canada by states and provinces. Am. Midl. Nat. 48(3): 574-603.


___________________________. 1957. Handbook of snakes of the United States and Canada. Ithaca, N. Y.: Comstock Publishing Co.