Anaxyrus microscaphus (Cope, 1867)

Class: Amphibia > Order: Anura > Family: Bufonidae > Genus: Anaxyrus > Species: Anaxyrus microscaphus

Bufo microscaphus Cope, 1867 "1866", Proc. Acad. Nat. Sci. Philadelphia, 18: 301. Syntypes: USNM 4106 (now lost), 4184, and 132901 according to Cochran, 1961, Bull. U.S. Natl. Mus., 220: 35 (who did not note 4106); USNM 4184 designated lectotype by Shannon, 1949, Bull. Chicago Acad. Sci., 8: 307. Type localities: "Territory of Arizona, . . . chiefly near the parallel of 35°, and along the valley of the Colorado from Fort Mojave to Fort Yuma" and "upper Colorado region"; restricted to "Fort Mohave, Mohave County, Arizona", USA, by Shannon, 1949, Bull. Chicago Acad. Sci., 8: 307 (see comment on lectotype designation by Shannon, 1953, Herpetologica, 9: 182-183).

Bufo lentiginosus microscaphus — Garman, 1884, Bull. Essex Inst., 16: 43, by implication.

Bufo woodhousii microscaphus — Shannon, 1949, Bull. Chicago Acad. Sci., 8: 301.

Bufo microscaphus microscaphus — Stebbins, 1951, Amph. W. North Am.: 274.

Anaxyrus microscaphus — Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006, Bull. Am. Mus. Nat. Hist., 297: 363.

Bufo (Anaxyrus) microscaphus — Fouquette and Dubois, 2014, Checklist N.A. Amph. Rept.: 305. See comment under Bufonidae regarding how this arrangement is part of a a system that requires widespread paraphyly. 

Common Names

Western Toad (Yarrow, 1876, List Skeletons and Crania: 39). 

Small Spaded Toad (Yarrow, 1882, Bull. U.S. Natl. Mus., 24: 23).

Cope Toad (Stebbins, 1951, Amph. W. North Am.: 266).

Southwestern Toad (Schmidt, 1953, Check List N. Am. Amph. Rept., Ed. 6: 64; Conant, Cagle, Goin, Lowe, Neill, Netting, Schmidt, Shaw, Stebbins, and Bogert, 1956, Copeia, 1956: 176 Stebbins, 1966, Field Guide W. North Am. Rept. Amph.: 61; Collins, Huheey, Knight, and Smith, 1978, Herpetol. Circ., 7: 10; Liner, 1994, Herpetol. Circ., 23: 17 Frank and Ramus, 1995, Compl. Guide Scient. Common Names Amph. Rept. World: 42).

Fort Mojave Toad (Schmidt, 1953, Check List N. Am. Amph. Rept., Ed. 6: 64).

Arizona Toad (Schmidt, 1953, Check List N. Am. Amph. Rept., Ed. 6: 64; Conant, Cagle, Goin, Lowe, Neill, Netting, Schmidt, Shaw, Stebbins, and Bogert, 1956, Copeia, 1956: 176; Stebbins, 1966, Field Guide W. North Am. Rept. Amph.: 62; Collins, Huheey, Knight, and Smith, 1978, Herpetol. Circ., 7: 10; Frank and Ramus, 1995, Compl. Guide Scient. Common Names Amph. Rept. World: 42; Collins, 1997, Herpetol. Circ., 25: 11; Crother, Boundy, Campbell, de Queiroz, Frost, Highton, Iverson, Meylan, Reeder, Seidel, Sites, Taggart, Tilley, and Wake, 2001 "2000", Herpetol. Circ., 29: 8; Stebbins, 2003, Field Guide W. Rept. Amph., Ed. 3: 213; Frost, McDiarmid, and Mendelson, 2008, in Crother (ed.), Herpetol. Circ., 37: 4; Liner and Casas-Andreu, 2008, Herpetol. Circ., 38: 8; Collins and Taggart, 2009, Standard Common Curr. Sci. Names N. Am. Amph. Turtles Rept. Crocodil., ed. 6: 6; Frost, McDiarmid, Mendelson, and Green, 2012, in Crother (ed.), Herpetol. Circ., 39: 13).

Distribution

Virgin River drainage of southern Nevada and southwestern Utah, and in adjacent California along the Colorado drainage, thence southwest across the Mogollon Plateau of central Arizona to the Mogollon Mountains of New Mexico (Catron, Grant, Luna, Sierra, and Socorro counties), USA.

Geographic Occurrence

Natural Resident: United States of America, United States of America - Arizona, United States of America - California, United States of America - Nevada, United States of America - New Mexico, United States of America - Utah

Endemic: United States of America

Comment

In the Bufo americanus group according to Blair, 1959, Texas J. Sci., 11: 427. Shannon, 1949, Bull. Chicago Acad. Sci., 8: 307, redescribed the lectotype. See comment under Bufo californicus. See account by Price and Sullivan, 1988, Cat. Am. Amph. Rept., 415: 1–3. Cocroft and Ryan, 1995, Animal Behav., 49: 283–303, discussed advertisement call in an evolutionary context. Considered until recently to include Anaxyrus mexicanus and Anaxyrus californicus as subspecies; see comment under Anaxyrus californicus for access to pertinent literature. Stebbins, 2003, Field Guide W. Rept. Amph., Ed. 3: 213–214, provided a brief account, figure, and map, and who noted areas of extensive hybridization with Anaxyrus woodhousii. Schwaner and Sullivan, 2005, in Lannoo (ed.), Amph. Declines: 422–424, provided a detailed account, map, and conservation status. Schwaner and Sullivan, 2009, Herpetol. Conserv. Biol., 4: 198–206, discussed introgressive hybridization with Anaxyrus woodhousii (as Bufo) in southwestern Utah, USA. Dodd, 2013, Frogs U.S. and Canada, 1: 127–132, provided an account that summarized relevant literature and noted the extinction of this species in the Las Vegas wash area of Nevada, USA. Elliot, Gerhardt, and Davidson, 2009, Frogs and Toads of N. Am.: 170–171, provided an account, photos, and advertisement call. Altig and McDiarmid, 2015, Handb. Larval Amph. US and Canada: 181–182, provided an account of larval morphology and biology. Sullivan, Wooten, Schwaner, Sullivan, and Takahashi, 2015, J. Herpetol., 49: 150-156, reported on mybridization of this species and Anaxyrus woodhousii along the Agua Fria River of central Arizona, USA, on the basis of morphology and mtDNA. Wooten, Klooster, Brown, Bradford, Schwaner, and Sullivan, 2018, J. Arizona–Nevada Acad. Sci., 47: 45–52, characterized microsatellite markers with reference to a hybrid zone with Anaxyrus woodhousii in southern Yavapai County, Arizona. Wooten, Sullivan, Klooster, Schwaner, Sullivan, Brown, Takahashi, and Bradford, 2019, J. Herpetol., 53: 104–114, reported on 30 years of hybridization with Anaxyrus woodhousii on the Agua Fria river in Arizona, USA. Painter, Stuart, Giermakowski, and Pierce, 2017, Western Wildlife, 4: 35, commented on the status and county range in New Mexico, USA. Driver, Eversole, Unger, Kulhavy, Schalk, and Hung, 2023, Ecologies, 4: 762–778, reported on the effects of climate change on the modeled distribution. Oyler-McCance, Ryan, Sullivan, Fike, Cornman, Giermakowski, Zimmerman, Harrow, Hedwall, Hossack, Latella, Lovich, Siefken, Sigafus, and Muths, 2024, Conserv. Genetics, 25: 835–848, reported on genetic connectivity of populations with reference to conservation units.  

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