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Home/Species/ Couch's Spadefoot

Scaphiopus couchii

Baird, 1854

Couch's Spadefoot

G5Secure Found in 17 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.105658
Element CodeAAABF01020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassAmphibia
OrderAnura
FamilyScaphiopodidae
GenusScaphiopus
Synonyms
Scaphiopus variusSpea laticeps
Other Common Names
Couch's spadefoot (EN)
Concept Reference
Frost, D. R. 1985. Amphibian species of the world. A taxonomic and geographical reference. Allen Press, Inc., and The Association of Systematics Collections, Lawrence, Kansas. v + 732 pp.
Taxonomic Comments
Garcia-Paris et al. (2003) used mtDNA to examine the phylogentic relationships of Pelobatoidea and found that the family Pelobatidae, as previously defined, is not monophyletic (Pelobates is sister to Megophryidae, not to Spea/Scaphiopus). They split the Pelobatidae into two families: Eurasian spadefoot toads (Pelobates), which retain the name Pelobatidae, and North American spadefoot toads (Scaphiopus, Spea), which make up the revived family Scaphiopodidae.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-07-24
Change Date2001-11-29
Edition Date2023-07-24
Edition AuthorsHammerson, G. (2011); rev. R. L. Gundy (2023)
Threat ImpactLow
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 to >300
Rank Reasons
This species is widespread throughout the southwestern United States and northern Mexico. No major threats are known at this time. However, future changes in the climate are expected to significantly impact this species. It is generally abundant where present and breeds explosively when conditions are appropriate.
Range Extent Comments
Couch's spadefoot is found in southeastern Colorado, western Oklahoma, western Texas, New Mexico, Arizona, and southeastern California in the United States and southern Baja California, Nayarit, Zacatecas, San Luis Potosi, and northern Veracruz in Mexico (Conant and Collins 1991, Mulcahy and Setser 2002, Stebbins 2003).
Occurrences Comments
There are many occurrences throughout the range extent (GBIF 2023, iNaturalist 2023).
Threat Impact Comments
Invasive saltcedar (Tamarix spp.) degrades habitat quality in riparian areas and can reduce or even eliminate Couch's spadefoot from the habitat (Riddle and Bateman 2020). This species is considered extremely vulnerable to climate change under all climate models examined, although the impact and timing is not known (Griffis-Kyle et al. 2018). At this time, chytrid fungus (Batrachochytrium dendrobatidis) does not appear to be threatening this species (Christman and Jennings 2018, Hernández-Martínez et al. 2019, Watters et al. 2016).
Ecology & Habitat

Description

Vertically elliptical pupil (in bright light); single hard, black, sickle-shaped spade on each hind foot; parotoid glands present but indistinct; adult snout-vent length often 6-7 cm, rarely up to 9 cm. Mature male: greenish yellow with scattered dark spots; dark patches on the inner three digits of mature individuals during breeding season; expanded vocal sac large and evenly rounded; breeding call a croaking yeow. Female: greenish yellow; coarse dark mottling of juveniles becomes a finer dark reticulation in adults. Larvae: dorsum usually bronze, dark brown, or dark gray to black (black in preservative); body typically wider in rear than in front; tail fin clear with fine scattered dark dots and lines that are most numerous in dorsal fin; eyes dorsal; intestine visible through skin; jaws serrated, never cusped; lower mandible striated; labial tooth rows usually 4/4, 4/5, or 5/5; oral papillae completely encircle mouth (narrow dorsal gap may be present); no keratinized area on roof of mouth; anus on midline at front end of ventral tail fin; usually not more than 3.5 cm total length. Eggs: black on top, whitish underneath, diameter 1.3-1.6 mm, surrounded by one jelly envelope; deposited as a cluster, cylindrical mass, or string of several to more than 100. Source: Hammerson (1999).

Habitat

Habitat includes arid and semi-arid shrublands, shortgrass plains, mesquite savanna, creosote bush desert, thornforest, cultivated areas, and tropical deciduous forest (Mexico). These toads spend most of their time underground or in rodent burrows, except when rains stimulate activity and bring them to the surface. Females attach eggs to vegetation in shallow ephemeral water resulting from heavy rains.

Ecology

Monogenean parasite infection may reduce spadefoot reproduction and/or survival (Tocque 1993).

Reproduction

These toads emerge from the ground and breed explosively after heavy rains in spring or summer. Breeding choruses usually last only 1 day. Females produce a clutch of up to several hundred eggs, divided among several clusters. Eggs and larvae develop quickly, and toadlets leave the pools in only about 1-2 weeks, if breeding pools do not dry up sooner than this. A newly laid Couch's spadefoot egg can develop into a tiny land-dwelling toadlet in only 1-2 weeks.
Terrestrial Habitats
Forest - HardwoodWoodland - HardwoodShrubland/chaparralSavannaGrassland/herbaceousDesertCropland/hedgerowSuburban/orchard
Palustrine Habitats
TEMPORARY POOL
Other Nations (1)
United StatesN5
ProvinceRankNative
ArizonaS5Yes
TexasS5Yes
CaliforniaS2Yes
New MexicoS4Yes
ColoradoS1Yes
OklahomaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
8 - Invasive & other problematic species, genes & diseasesRestricted (11-30%)Moderate - slightHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesRestricted (11-30%)Moderate - slightHigh (continuing)
8.1.2 - Named speciesRestricted (11-30%)Moderate - slightHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.1 - Habitat shifting & alterationPervasive (71-100%)UnknownHigh - moderate
11.2 - DroughtsPervasive (71-100%)UnknownHigh - moderate

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Roadless Areas (17)
Arizona (13)
AreaForestAcres
BoulderTonto National Forest40,359
Butterfly Roadless AreaCoronado National Forest42,296
Catalina St. Pk. Roadless AreaCoronado National Forest951
Cdo WsaCoronado National Forest1,955
ChiricahuaCoronado National Forest76,876
GaliuroCoronado National Forest28,333
Lower San FranciscoApache-Sitgreaves National Forests59,310
Middle Romero WSRCoronado National Forest60
Oracle RoadlessCoronado National Forest22,365
PinalenoCoronado National Forest130,920
Santa RitaCoronado National Forest6,078
TumacacoriCoronado National Forest44,594
WhetstoneCoronado National Forest20,728
New Mexico (4)
AreaForestAcres
Apache Kid ContiguousCibola National Forest67,542
Lower San FranciscoGila National Forest26,460
Peloncillo (NM)Coronado National Forest43,339
West Face Sacramento MountainsLincoln National Forest41,176
References (16)
  1. Behler, J. L., and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. Alfred A. Knopf, New York. 719 pp.
  2. Blackburn, L., P. Nanjappa, and M. J. Lannoo. 2001. An Atlas of the Distribution of U.S. Amphibians. Copyright, Ball State University, Muncie, Indiana, USA.
  3. Bragg, A.N. 1965. Gnomes of the night. the spadefoot toads. 127 pp.
  4. Conant, R. and J. T. Collins. 1991. A field guide to reptiles and amphibians: eastern and central North America. Third edition. Houghton Mifflin Co., Boston, Massachusetts. 450 pp.
  5. Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]
  6. Frost, D. R. 1985. Amphibian species of the world. A taxonomic and geographical reference. Allen Press, Inc., and The Association of Systematics Collections, Lawrence, Kansas. v + 732 pp.
  7. Frost, D.R. 2020. Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History, New York, USA. Online: http://research.amnh.org/herpetology/amphibia/index.html
  8. García-París, M., D.R. Buchholtz, and G. Parra-Olea. 2003. Phylogenetic relationships of Pelobatoidea re-examined using mtDNA. Molecular Phylogenetics and Evolution 28:12-23.
  9. Hammerson, G. A. 1982b. Amphibians and reptiles in Colorado. Colorado Division of Wildlife, Denver. vii + 131 pp.
  10. Hammerson, G. A. 1999. Amphibians and reptiles in Colorado. Second edition. University Press of Colorado, Boulder. xxvi + 484 pp.
  11. Mulcahy, D. G., and K. W. Setser. 2002. Geographic distribution: <i>Scaphiopus couchii</i>. Herpetological Review 33:64.
  12. Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
  13. Stebbins, R.C. 1985b. A Field Guide to the Reptiles and Amphibians of Eastern North America. Houghton Mifflin Company. Boston, Massachusetts.
  14. Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
  15. Tocque, K. 1993. The relationship between parasite burden and host resources in the desert toad (<i>Scaphiopus couchii</i>), under natural environmental conditions. J. Anim. Ecol. 62:683-693.
  16. Wasserman, A.O. 1970. <i>Scaphiopus couchii</i>. Catalogue of American Amphibians and Reptiles. 85:1-4.