Overview

Comprehensive Description

Description

A small toad of the family Pelobatidae, the genus is characteristically short-legged and squat, having vertical "cat-eye" pupils, and a black, keratinized spade (used for burrowing) on the underside of each hind foot.Their skin is relatively smooth compared to the rough, warty epidermis of truetoads (genus Bufo). Females are slighty larger than males. Distinguishing features include a slightly upturned, "pug-nose", a raised callus, or boss, between the eyes, and a dark brown or orange spot on each upper eyelid. Dorsal coloration is similar to that of other Spea and Scaphiopus species: Usually a brown, gray, or olive background, mottled with darker spots posessing light-colored centers. The ground color is variable and often matches the substrate. The venter is light gray, white, or creamy.

Tadpoles have large, globular or ovoid bodies, reaching 70 mm in total length. Their dorsal coloration is black, brown, or dark gray and flecked with metallic golds and rusts, while the abdomen displays an overall golden irridescence. The spiracle is located low on the abdomen, and to the left side.

  • Orchard, S.A. (1992). ''Amphibian population declines in British Columbia.'' Declines in Canadian amphibian populations: designing a national monitoring strategy. C. A. Bishop nd K.E. Petit, eds., Canadian Wildlife Service, 10-13.
  • Drost, C. A., and Fellers, G. M. (1996). "Collapse of a regional frog fauna in the Yosemite area of the California Sierra Nevada, USA." Conservation Biology, 10(2), 414-425.
Creative Commons Attribution 3.0 (CC BY 3.0)

© AmphibiaWeb © 2000-2011 The Regents of the University of California

Source: AmphibiaWeb

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Global Range: Southern British Columbia (Cannings 1999) southward through central and eastern Washington and Oregon, southern Idaho, eastern California, Nevada, Utah, Wyoming, and northwestern Colorado to northwestern Arizona (Hall 1998). From edge of Cascade-Sierra axis east to the Rockies. To elevations of about 9,200 ft (Stebbins 1985).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Range Description

This species can be in Southern British Columbia, Canada (Cannings 1999) southward in the USA through central and eastern Washington and Oregon, southern Idaho, eastern California, Nevada, Utah, Wyoming, and northwestern Colorado to northwestern Arizona (Hall 1998). It can be found from the edge of Cascade-Sierra axis east to the Rockies. It is found at elevations of about 850m asl (Stebbins 1985).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution and Habitat

This species lives in western North America, in the United States and Canada. In Calfornia, they occur east of the Sierra Nevada, and north of San Bernardino Co. They occur throughout Nevada and Utah east of the Colorado River, push just south into northwest Arizona, and north into northwest Colorado and southwest Wyoming. In Canada, Washington and Oregon, they are sandwiched between the Cascade and Rocky Mtn. ranges, but occur throughout lower Idaho. They are found in arid regions, often associated with high desert scrub and sagebrush, but also reach past the pinion-juniper woodland, and into the spruce-fir belt at about 2800 m (9200 ft).

Little is known about abundance due, in part, to its explosive breeding habits, but it is often heard in temporary pools and flooded ditches immediately after winter and spring rains.

Activity varies with local conditions, but it is most active during and after winter, spring, and sometimes summer rains, when it may emerge to breed or forage on wet nights.

  • Orchard, S.A. (1992). ''Amphibian population declines in British Columbia.'' Declines in Canadian amphibian populations: designing a national monitoring strategy. C. A. Bishop nd K.E. Petit, eds., Canadian Wildlife Service, 10-13.
  • Drost, C. A., and Fellers, G. M. (1996). "Collapse of a regional frog fauna in the Yosemite area of the California Sierra Nevada, USA." Conservation Biology, 10(2), 414-425.
Creative Commons Attribution 3.0 (CC BY 3.0)

© AmphibiaWeb © 2000-2011 The Regents of the University of California

Source: AmphibiaWeb

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Geographic Range

Great Basin spadefoot toads are found in the United States and Canada. The species occurs in northwest Arizona, in California east of the Sierra Nevada mountain range, northwestern Colorado, lower Idaho, southwestern Wyoming, throughout Nevada and Utah, and between the Cascade and Rocky Mountain ranges in Oregon, Washington, and British Columbia.

Biogeographic Regions: nearctic (Native )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Physical Description

Morphology

Physical Description

Great Basin spadefoot toads usually have a gray, olive, or brown colored dorsal coloration mottled with darker spots with light-colored centers. Gray streaks outline an hourglass shaped marking on the back. The coloration is similar to that of other species of the genera Spea and Scaphiopus. Ventral coloration is light gray, white, or creamy and without markings. The skin is relatively smooth compared to the rough, warty nature of true toads (genus Bufo), but still contains small bumps. Parotoid glands seem to be absent. There is a dark brown or orange spot present on each upper eyelid. Pupils are vertical, and the eyes are large, catlike, golden yellow, and located on the side of the head. The nose is slightly upturned and there is a raised callus between the eyes. The body is short and fat with stubby limbs. Spadefoot toads get their name from the presence of a black, keratinized spade, or tubercle, on the underside of each hind foot, which is used for burrowing behavior. Adult body lengths vary from 32 to 67 mm and females tend to be only slightly larger than males. Tadpoles have large globular bodies and can reach 70 mm in length. They are colored black, brown, and gaey with scattered golden specks.

When threatened, adult Great Basin spadefoot toads can produce noxious skin secretions, which are probably poisonous or at least distasteful to predators.

Range length: 32 to 67 mm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; poisonous

Sexual Dimorphism: sexes alike; female larger

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Size

Length: 5 cm

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Type Information

Syntype for Spea intermontana
Catalog Number: USNM 25335
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1872
Locality: No Further Locality Data, Utah, United States, North America
  • Syntype: Cope, E. D. 1872. Report upon Geographical and Geological Explorations and Surveys West of the Hundredth Meridian in Charge of First Lieutenant George M. Wheeler, Zoology. 525, plate 25, figures 6-8.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Syntype for Spea intermontana
Catalog Number: USNM 8188
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1872
Locality: No Further Locality Data, Utah, United States, North America
  • Syntype: Cope, E. D. 1872. Report upon Geographical and Geological Explorations and Surveys West of the Hundredth Meridian in Charge of First Lieutenant George M. Wheeler, Zoology. 525, plate 25, figures 6-8.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Syntype for Spea intermontana
Catalog Number: USNM 8653
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1872
Locality: No Further Locality Data, Utah, United States, North America
  • Syntype: Cope, E. D. 1872. Report upon Geographical and Geological Explorations and Surveys West of the Hundredth Meridian in Charge of First Lieutenant George M. Wheeler, Zoology. 525, plate 25, figures 6-8.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Palouse Grasslands Habitat

This taxon is found in the Palouse grasslands, among other North American ecoregions. The Palouse ecoregion extends over eastern Washington, northwestern Idaho and northeastern Oregon. Grasslands and savannas once covered extensive areas of the inter-mountain west, from southwest Canada into western Montana in the USA. Today, areas like the great Palouse prairie of eastern  are virtually eliminated as natural areas due to conversion to rangeland. The Palouse, formerly a vast expanse of native wheatgrasses (Agropyron spp), Idaho Fescue (Festuca idahoensis), and other grasses, has been mostly plowed and converted to wheat fields or is covered by Drooping Brome (Bromus tectorum) and other alien plant species.

the Palouse historically resembled the mixed-grass vegetation of the Central grasslands, except for the absence of short grasses. Such species as Bluebunch Wheatgrass (Elymus spicatus), Idaho Fescue (Festuca idahoensis) and Giant Wildrye (Elymus condensatus) and the associated species Lassen County Bluegrass (Poa limosa), Crested Hairgrass (Koeleria pyramidata), Bottlebrush Squirrel-tail (Sitanion hystrix), Needle-and-thread (Stipa comata) and Western Wheatgrass (Agropyron smithii) historically dominated the Palouse prairie grassland.

Representative mammals found in the Palouse grasslands include the Yellow-bellied Marmot (Marmota flaviventris), found burrowing in grasslands or beneath rocky scree; American Black Bear (Ursus americanus); American Pika (Ochotona princeps); Coast Mole (Scapanus orarius), who consumes chiefly earthworms and insects; Golden-mantled Ground Squirrel (Spermophilus lateralis); Gray Wolf (Canis lupus); Great Basin Pocket Mouse (Perognathus parvus); Northern River Otter (Lontra canadensis); the Near Threatened Washington Ground Squirrel (Spermophilus washingtoni), a taxon who prefers habitat with dense grass cover and deep soils; and the Northern Flying Squirrel (Glaucomys sabrinus), a mammal that can be either arboreal or fossorial.

There are not a large number of amphibians in this ecoregion. The species present are the Great Basin Spadefoot Toad (Spea intermontana), a fossorial toad that sometimes filches the burrows of small mammals; Long-toed Salamander (Ambystoma macrodactylum); Northern Leopard Frog (Glaucomys sabrinus), typically found near permanent water bodies or marsh; Columbia Spotted Frog (Rana luteiventris), usually found near permanent lotic water; Pacific Treefrog (Pseudacris regilla), who deposits eggs on submerged plant stems or the bottom of water bodies; Tiger Salamander (Ambystoma tigrinum), fossorial species found in burrows or under rocks; Woodhouse's Toad (Anaxyrus woodhousii), found in arid grasslands with deep friable soils; Western Toad (Anaxyrus boreas), who uses woody debris or submerged vegetation to protect its egg-masses.

There are a limited number of reptiles found in the Palouse grasslands, namely only: the Northern Alligator Lizard (Elgaria coerulea), often found in screes, rock outcrops as well as riparian vicinity; the Painted Turtle (Chrysemys picta), who prefers lentic freshwater habitat with a thick mud layer; Yellow-bellied Racer (Chrysemys picta); Ringneck Snake (Diadophis punctatus), often found under loose stones in this ecoregion; Pygmy Short-horned Lizard (Phrynosoma douglasii), a fossorial taxon often found in bunchgrass habitats; Side-blotched Lizard (Uta stansburiana), frequently found in sandy washes with scattered rocks; Southern Alligator Lizard (Elgaria multicarinata), an essentially terrestrial species that prefers riparian areas and other moist habitats; Pacific Pond Turtle (Emys marmorata), a species that usually overwinters in upland habitat; Western Rattlesnake (Crotalus viridis), who, when inactive, may hide under rocks or in animal burrows; Night Snake (Hypsiglena torquata); Western Skink (Plestiodon skiltonianus), who prefers grasslands with rocky areas; Western Terrestrial Garter Snake (Thamnophis elegans), found in rocky grasslands, especially near water; Rubber Boa (Charina bottae).

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© C. Michael Hogan & World Wildlife Fund

Supplier: C. Michael Hogan

Trusted

Article rating from 2 people

Average rating: 3.0 of 5

Comments: Mainly sagebrush flats, semi-desert shrublands, pinyon-juniper woodland. Digs its own burrow in loose soil or uses those of small mammals. Breeds in temporary or permanent water, including rain pools, pools in intermittent streams, and flooded areas along streams. Eggs are attached to vegetation in water or placed on bottom of pool.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Habitat and Ecology

Habitat and Ecology
This species is found mainly in sagebrush flats, semi-desert shrublands, pinyon-juniper woodland. Digs its own burrow in loose soil or uses those of small mammals. Breeds in temporary or permanent water, including rain pools, pools in intermittent streams, and flooded areas along streams. Eggs are attached to vegetation in water or placed on bottom of pool.

Systems
  • Terrestrial
  • Freshwater
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Mojave Desert Habitat

This taxon is found in the Mojave Desert, the smallest of the four North American deserts. While the Mojave lies between the Great Basin Shrub Steppe and the Sonoran Desert, its fauna is more closely allied with the lower Colorado division of the Sonoran Desert. Dominant plants of the Mojave include Creosote Bush (Larrea tridentata), Many-fruit Saltbush (Atriplex polycarpa), Brittlebush (Encelia farinosa), Desert Holly (Atriplex hymenelytra), White Burrobush (Hymenoclea salsola), and Joshua Tree (Yucca brevifolia), the most notable endemic species in the region.

The Mojave’s warm temperate climate defines it as a distinct ecoregion. Mojave indicator species include Spiny Menodora (Menodora spinescens), Desert Senna (Cassia armata), Mojave Indigobush (Psorothamnus arborescens), and Shockley's Goldenhead (Acamptopappus shockleyi). The Mojave supports numerous species of cacti, including several endemics, such as Silver Cholla (Opuntia echinocarpa), Mojave Prickly Pear (O. erinacea), Beavertail Cactus (O. basilaris), and Cotton-top Cactus (Echinocactus polycephalus).

While the Mojave Desert is not so biologically distinct as the other desert ecoregions, distinctive endemic communities occur throughout. For example, the Kelso Dunes in the Mojave National Preserve harbor seven species of endemic insects, including the Kelso Dunes Jerusalem Cricket (Ammopelmatus kelsoensis) and the Kelso Dunes Shieldback Katydid (Eremopedes kelsoensis). The Mojave Fringe-toed Lizard (Uma Scoparia), while not endemic to the dunes, is rare elsewhere. Flowering plants also attract butterflies such as the Mojave Sooty-wing (Pholisora libya), and the widely distributed Painted Lady (Vanessa cardui).

There are a total of eight amphibian species present in the Mojave Desert all of which are anuran species: the endemic Relict Leopard Frog (Lithobates onca); the endemic Amargosa Toad (Anaxyrus nelsoni); Lowland Leopard Frog (Lithobates yavapaiensis); Red-spotted Toad (Anaxyrus punctatus); Southwestern Toad (Anaxyrus microscaphus); Great Basin Spadefoot (Spea intermontana); Great Plains Toad (Anaxyrus cognatus); and the Pacific Treefrog (Pseudacris regilla).

The native range of California’s threatened Desert Tortoise (Gopherus agassizii) includes the Mojave and Colorado Deserts. The Desert Tortoise has adapted for arid habitats by storing up to a liter of water in its urinary bladder. The following reptilian fauna are characteristic of the Mojave region in particular: Gila Monster (Heloderma suspectum NT); Western Banded Gecko (Coleonyx variegatus), Northern Desert Iguana (Dipsosaurus dorsalis), Western Chuckwalla (Sauromalus obesus), and regal horned lizard (Phrynosoma solare). Snake species include the Desert Rosy Boa (Charina trivirgata gracia), Mojave Patchnose Snake (Salvadora hexalepis mojavensis), and Mojave Rattlesnake (Crotalus scutulatus).

Endemic mammals of the ecoregion include the Mojave Ground Squirrel (Spermophilus mohavensis) and Amargosa Vole (Microtus californicus scirpensis); and the California Leaf-nosed Bat (Macrotus californicus).

Creative Commons Attribution 3.0 (CC BY 3.0)

© C. Michael Hogan & World Wildlife Fund

Supplier: C. Michael Hogan

Trusted

Article rating from 1 person

Average rating: 2.5 of 5

Spea intermontana is found in arid regions, semi-desert shrubland, or sagebrush flats, but can also be found in alkali flats, pinion-juniper woodland, ponderosa pine, and high elevation spruce-fir forests at about 2800 m (9200 ft). Great Basin spadefoot toads require temporary or permanent water sources for breeding, such as slow-flowing springs, seasonal pools, irrigation ditches, and ponds. They are able to survive in arid habitats by remaining buried underground, thus their survival requires soils that permit burrowing.

Range elevation: 2800 (high) m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: desert or dune ; chaparral ; forest ; scrub forest ; mountains

Aquatic Biomes: temporary pools

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Migration

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Migrates up to several hundred meters between breeding pools and nonbreeding terrestrial habitats.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Trophic Strategy

Comments: Not well documented. Adults known to eat insects. Larvae probably eat algae, organic debris, plant tissue, etc., sometimes invertebrates and amphibian larvae.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Food Habits

Adult Great Basin Spadefoot toads are insectivores and carnivores who feed primarily at night. They are generalists, feeding on easily captured terrestrial insects and other arthropods. One study found that adult toads consumed at least 56 different arthropod taxa from the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Orthoptera, Trichoptera, Collembola, and Araneae. Due to their abundance in the native habitats of Great Basin spadefood toads, ants and darkling beetles are the most common sources of prey. Great Basin spadefoots do not have any particular preference, however, for one prey type over another. Toads are limited to eating species small enough for them to swallow whole, and tend not to eat species that produce noxious secretions, such as certain types of ground beetles. While plant matter has been found in the stomach contents of the toads, vegetation is not a primary source of food for adults of the species.

Little information is available regarding the feeding habits of Great Basin spadefoot toad larva. Tadpoles of spadefoot toads are omnivorous; they feed on water-born plant material such as algae, organic detritus, and small plants, as well as insects and other amphibian larvae. Tadpoles also feed on carrion and may even become cannibalistic, especially in breeding pools. Carnivorous larvae are able to grow and metamorphose faster due to the higher level of protein in their diet.

Animal Foods: amphibians; carrion ; insects; terrestrial non-insect arthropods

Plant Foods: algae; phytoplankton

Other Foods: detritus

Primary Diet: carnivore (Insectivore )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Associations

Ecosystem Roles

Great Basin spadefoot toads affect populations of the arthropods they prey on. Due to the relative stability of their populations, the species also helps maintain the populations of its predators, as the toads are a relatively consistent source of food. They have no symbiotic or mutualistic interactions with any other species. Parasites that infect the species include Polystoma nearcticum in the lung and bladder, Distoichometra bufonis in the small intestine, Aplectana incerta in the small and large intestine, species of the genera Physaloptera (larvae) in the stomach, and Acuariidea (larvae) in cysts on the stomach wall.

Commensal/Parasitic Species:

  • Goldberg, S., C. Bursey. 2002. HELMINTHS OF THE PLAINS SPADEFOOT, SPEA BOMBIFRONS,THE WESTERN SPADEFOOT, SPEA HAMMONDII, AND THE GREAT BASIN SPADEFOOT, SPEA INTERMONTANA. Western North American Naturalist, 62/4: 491-495.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Predation

Adult Great Basin spadefoot toads are preyed upon by western rattlesnakes, coyotes, and burrowing owls. Tadpoles are mainly preyed upon by western terrestrial garter snakes and American crows. When water levels rise high enough to flood breeding pools, tadpoles are also preyed upon by rainbow trout and brown trout.

When threatened, adult Great Basin spadefoot toads can produce noxious skin secretions, which are reported to smell like popcorn or roasted peanuts. The skin secretions are probably poisonous or at least distasteful to predators. They may even cause minor allergic reactions in humans, symptoms of which may include sneezing and a runny nose, and may also cause a burning sensation upon contact with the eyes and nose. Burrowing and camouflaged coloration may also help adult spadefoots escape predation. By contrast, tadpoles are comparatively helpless and have few defenses against predation other than cryptic coloration.

Known Predators:

Anti-predator Adaptations: cryptic

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Population Biology

Number of Occurrences

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Hundreds of occurrences.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Global Abundance

10,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but certainly exceeds 10,000.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

General Ecology

Predators include birds and probably fishes.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History and Behavior

Behavior

Communication and Perception

Males attract females to temporary breeding pools with loud calls while they are partially submerged in the water. These calls may also attract other males who will compete for the females. The calls are short, between 1 and 3 notes long, and duck-like. Because Spea intermontana is nocturnal, it has large eyes probably adapted to seeing at night. Great Basin spadefoot toads likely perceive their environment through a minimum of audio, visual, tactile and chemical stimuli.

Communication Channels: tactile ; acoustic ; chemical

Perception Channels: visual ; tactile ; acoustic ; chemical

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Cyclicity

Comments: Primarily nocturnal. Sometimes forages during the day.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life Cycle

Development

Eggs usually hatch within 2 to 4 days. Tadpoles transform in about 30 to 40 days, but the rate of metamorphosis can increase if the temporary pools in which the larvae are developing begin to dry out. Growth and differentiation rates are also influenced by temperature, which affects thyroid hormone activity (thyroid hormone is involved in metamorphosis). It is critical that larvae develop rapidly in species that breed in temporary pools, such as Spea intermontana, because metamorphosis must occur before the water evaporates, as the tadpoles cannot survive outside of water. Transformed juveniles still have a tail which disappears soon after they leave the breeding pools, and they may remain at the breeding location for a period of several days to several weeks before they leave the site. Transformed juveniles develop into sexually mature adults in 1 to 2 years for males, and in about 2 years for females.

  • Stebbins, R. 1954. Amphibians and Reptiles of Western North America. New York: McGraw-Hill.
  • 2010. "California Reptiles & Amphibians" (On-line). Accessed February 21, 2010 at http://www.californiaherps.com/frogs/pages/s.intermontana.html.
  • Buchholz, D., T. Hayes. 2002. Evolutionary Patterns of Diversity in Spadefoot Toad Metamorphosis. Copeia, 2002/1: 180-189.
  • Hall, J., J. Larsen, R. Fitzner. 1997. POSTEMBRYONIC ONTOGENY OF THE SPADEFOOT TOAD, SCAPHIOPUS INTERMONTANUS (ANURA: PELOBATIDAE): EXTERNAL MORPHOLOGY. Herpetological Monographs, 11: 124-178.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life Expectancy

Lifespan/Longevity

The lifespan of Great Basin spadefoot toads is unknown. It is assumed to be similar to other spadefoot toad species and is therefore estimated to be about 13 years for females and 11 years for males in the wild.

Typical lifespan

Status: wild:
11 to 13 years.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Lifespan, longevity, and ageing

Maximum longevity: 20 years (wild) Observations: While the average longevity of this animal is certainly much shorter, it has been suggested that dormant animals may have survived over 20 years in the arid Imperial Valley (http://www.fs.fed.us/database/feis/).
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Reproduction

Breeds sporadically May-July, often after spring or summer rains. Eggs laid in small packets of 20-40 eggs. Female may lay a total of about 300-500 eggs. Under optimal conditions eggs probably hatch in about 2-3 days (Nussbaum et al. 1983). Larval period lasts a few to several weeks.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Great Basin spadefoot toads are explosive breeders, with all breeding completed in a few days. There is no specific or definite breeding season, but all breeding takes place from May through August, when temperature and water availability is favorable. There is much variation in the timing of mating each year due to the nature of mating locations. Adults are terrestrial, but breeding sites are located around water sources. As a result, adults of the species must migrate to the breeding sites. These journeys typically occur at night in order to limit exposure to dangers such as evaporative water loss and predation. The factors that stimulate mating are not very well understood. Rainfall may be one of them, but is not necessary for it as is the case with other spadefoot toad species. Adults migrate anywhere from 1 to 5 km to reach breeding sites.

Males migrate to breeding sites, partially submerge near the shore, and attempt to attract females using loud calls 1 to 3 notes in length. The calls, or choruses, are reported to be monotonous duck-like snoring sounds, and may be heard over great distances. The choruses attract females, and probably other males, to the breeding pools. As females arrive, males scramble and compete to find mates. Reproduction involves amplexus, where males embrace females from behind using their forelimbs. This position allows males to externally fertilize the female eggs as they emerge from the females' cloacae. When mating is completed, the adults quickly burrow underground to avoid evaporative water loss.

Mating System: polygynandrous (promiscuous)

Great Basin spadefoot toads are explosive breeders, with all breeding completed in a few days. There is no specific or definite breeding season, but all breeding takes place from May through August, when temperature and water availability is favorable. There is much variation in the timing of mating each year due to the nature of mating locations.

The breeding pools may be permanent or temporary sources of water, such as rain-water pools, snowmelt, ponds, irrigation ditches, and streams. Breeding is more common in ephemeral water sources in areas where it rains enough to create temporary pools, and more common in permanent water sources in areas where it does not rain enough to create temporary pools. The water must be still or slow-moving to allow breeding. In order to support metamorphosis, breeding pools must remain filled for at least 40 days to allow enough time for eggs to hatch and for larval transformation.

After mating, females lay anywhere from 300 to 1000 eggs in small clusters of 10 to 40 eggs. They attach the egg clusters to floating sticks, submerged rocks, and underwater vegetation. Eggs usually hatch within 2 to 4 days, but may take longer if water temperatures are too cold.

The size of Great Basin spadefoot toads at sexual maturity is unknown. Males mature sexually in the first 1 to 2 years after metamorphosis, while females do not sexually mature until at least the second year after metamorphosis.

Breeding interval: Great Basin spadefoot toads breed an average of once yearly if conditions are favorable.

Breeding season: Great Basin spadefoot toads will breed from May through August when conditions are favorable.

Range number of offspring: 300 to 1000.

Range time to hatching: 2 to 4 days.

Average age at sexual or reproductive maturity (female): 2 years.

Range age at sexual or reproductive maturity (male): 1 to 2 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous

There is no parental involvement in the care for young once the eggs are laid. Females lay and attach their eggs to vegetation in bodies of water, and subsequently migrate back to feeding habitats, along with males, to replenish their energy reserves.

Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

Conservation Status

National NatureServe Conservation Status

Canada

Rounded National Status Rank: N3 - Vulnerable

United States

Rounded National Status Rank: N5 - Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Very narrow to narrow.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2004

Assessor/s
Geoffrey Hammerson

Reviewer/s
Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)

Contributor/s

Justification
Listed as Least Concern in view of its wide distribution, tolerance of a broad range of habitats, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Total adult population size is not knows but exceeds 10,000. The species has no special conservation status and populations seem to be stable. Natural habitats have mostly not been subject to threat, though agriculture has reduced and threatened some populations. Irrigation, however, could be creating new habitats, as it creates standing water sources necessary for breeding in areas previously inhospitable to the toads. Man-made reservoirs also account for a sizable number of breeding sites. The fact that the toads are generalized in their feeding habits is also good news for the survival of the species; the elimination or reduction of a particular species of prey will not significantly impact the availability of food. In general, Great Basin spadefoot toads have a good chance of survival wherever standing water is available and wherever soil allows for burrowing.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

  • Bradford, D., J. Jaeger, S. Shanahan. 2005. Distributional Changes and Population Status of Amphibians in the Eastern Mojave Desert. Western North American Naturalist, 65/4: 462-472.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Global Short Term Trend: Relatively stable (=10% change)

Comments: Area of occupancy and abundance are relatively stable.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Comments: Likely relatively stable in extent of occurrence, likely less than 25 percent decline in population size, area of occurrence, and number/condition of occurrences.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Population

Population
It is widespread and locally abundant. Range size and population levels are relatively stable.

Population Trend
Stable
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History, Abundance, Activity, and Special Behaviors

An explosive, opportunistic breeder, Spea intermontana is well adapted to the unpredictable and usually harsh seasons typical of the high desert areas it inhabits. Males have loud calls which attract females and probably other males to temporary or vernal pools where breeding takes place. Males are non-territorial, clumping and calling to females from partially submerged positions near the shore of pools. They appear to engage in a mad scramble for mates as they arrive. After breeding, adults disappear underground by using the spades on their hindfeet to burrow backward into the soil, thereby avoiding evaporative water loss to the dry desert air.

Eggs are laid underwater in groups of 10-40, and depending on the type of vegetation and substrate available, are arranged in either flat sheets, short strings, or golfball sized clusters.

Tadpoles may be either herbivorous or carnivorous, depending on local environmental conditions. The carnivorous morph has an enormous head, large jaw adductor muscles, and a sharp keratinous beak for tearing and cutting flesh. Tadpoles develop quickly to avoid dessication in their rapidly drying temporary pools.

  • Orchard, S.A. (1992). ''Amphibian population declines in British Columbia.'' Declines in Canadian amphibian populations: designing a national monitoring strategy. C. A. Bishop nd K.E. Petit, eds., Canadian Wildlife Service, 10-13.
  • Drost, C. A., and Fellers, G. M. (1996). "Collapse of a regional frog fauna in the Yosemite area of the California Sierra Nevada, USA." Conservation Biology, 10(2), 414-425.
Creative Commons Attribution 3.0 (CC BY 3.0)

© AmphibiaWeb © 2000-2011 The Regents of the University of California

Source: AmphibiaWeb

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Threats

Comments: Most of habitat is not subject to incompatible uses or major threats, but intensive-extensive agriculture likely has extirpated/reduced some populations.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Major Threats
Most of its habitat is not subject to incompatible uses or major threats.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History, Abundance, Activity, and Special Behaviors

Officially unthreatened, but recent studies have detected possible declines (Orchard 1992) and a repeat survey of historic collecting sites in the Sierra Nevada (Drost and Fellers 1996) found no specimens of Spea intermontana.

  • Orchard, S.A. (1992). ''Amphibian population declines in British Columbia.'' Declines in Canadian amphibian populations: designing a national monitoring strategy. C. A. Bishop nd K.E. Petit, eds., Canadian Wildlife Service, 10-13.
  • Drost, C. A., and Fellers, G. M. (1996). "Collapse of a regional frog fauna in the Yosemite area of the California Sierra Nevada, USA." Conservation Biology, 10(2), 414-425.
Creative Commons Attribution 3.0 (CC BY 3.0)

© AmphibiaWeb © 2000-2011 The Regents of the University of California

Source: AmphibiaWeb

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
No conservation measures are needed. It occurs in many protected areas.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

There are no known adverse effects of Spea intermontana on humans. When threatened, adult Great Basin spadefoot toads can produce noxious skin secretions which may cause minor allergic reactions in humans, symptoms of which may include sneezing and a runny nose, and may also cause a burning sensation upon contact with the eyes and nose.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Economic Importance for Humans: Positive

Members of this species have few interactions with humans, positive or negative.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Great Basin spadefoot

The Great Basin spadefoot (Spea intermontana) is a species of toad in the Scaphiopodidae family. It is 3.8 to 6.3 cm long and is usually colored gray, olive or brown. Great Basin spadefoot toads have adapted to life in dry habitats. They use the hard, keratinized spade on each foot to dig a burrow, where they spend long periods during cold and dry weather. They are opportunistic hunters and will eat anything they can subdue. While their tadpoles have numerous predators, adults are able to produce skin secretions that deter enemies.

Contents

Identification

The Great Basin spadefoot ranges from 3.8 to 6.3 cm long.[2] It is usually gray, olive or brown colored. Gray streaks outline an hourglass shaped marking on the back. The skin is smooth compared with the bumpy skin of the true toads in the genus Bufo. There is a spade present on the inside of each hind foot; it has sharp edges and is wedge-shaped. A glandular boss is present between the eyes. Eyes are catlike; pupils are vertical in bright light and round at night. Dark brown spots are present on each upper eyelid.

Habitat and distribution

The natural habitats of the Great Basin spadefoot include pinyon-juniper, ponderosa pine, and high elevation (up to 2,600 m[3]) spruce-fir forests, semidesert shrubland, sagebrush flats, temperate grasslands, and deserts. They are present in agricultural areas as well. The Great Basin Spadefoot can be found from southern British Columbia through the eastern portions of Washington and Oregon and in southern Idaho. Their range extends throughout all of Nevada and into most of Utah; they are also present in small areas in California, Arizona, Colorado, and Wyoming.[4][2]

Reproduction

Breeding

Breeding is explosive, meaning that large congregations of individuals assemble and mate with each other. Adults are terrestrial and must migrate to breeding sites. Breeding may take place in permanent or temporary water sources such as springs, sluggish streams, and manmade reservoirs during the months of April through July. Spring rains usually provide the stimulus for males to emerge from their burrows for breeding, although unlike other spadefoots (Scaphiopus spp.), Great Basin spadefoots do breed during periods of no rainfall. The stimulus for breeding in the absence of rain is unknown. Males move to breeding waters first and begin vocalizing.[5] Once females arrive, there is a race to mate with as many others as possible, and physical contests between males are common.

Females usually lay 300–500 eggs contained in a sticky gel, but have been reported lay as many as 1000 eggs in captivity. The female deposits her fertilized eggs in several different locations within the breeding water: on vegetation, rocks, bottom of the pool, or anything else that anchors the eggs. After mating, females return to their burrows. Males stay at the breeding pool and continue vocalizing until females stop arriving (presumably because all females in the vicinity have mated); then the males also return to their burrows.[3]

Development

Eggs hatch in 2 to 4 days,[6] and the tadpole development and metamorphosis is complete within 4 to 8 weeks, depending upon temperature, food quality, and food quantity. Developing rapidly helps Great Basin spadefoots avoid desiccation and consequent death in their arid environment.[3]

Young morphs (metamorphosed preadults) are small, about 0.8 inch (19 mm) in length on average.[6][7] They have high surface-to-volume ratios; therefore, they are highly susceptible to desiccation and seek shade cover immediately after emerging from breeding pools. They grow, by about 110% in lengthand 1,100% in mass over 3 months under laboratory conditions.[7] Tadpoles may be carnivorous or herbivorous, depending on environmental conditions. Different larval diets are associated with different morphological characteristics.[8]

Behavior

Diet

Adult spadefoots are opportunistic carnivores. Adults have been shown to eat arthropods from the taxa Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Orthoptera, Trichoptera, Collembola, and Araneae. Ants and beetles are their most common prey. Feeding seems to be generalized and opportunistic; the toads will eat anything they can subdue.[3]

Adults hunt in spring and summer, but only at night or during light rains. Spadefoot tadpoles are dimorphic. Within a cohort, some tadpoles have large mouthparts, while others have much smaller mouthparts. As well as consuming other types of food, large-mouthed individuals are cannibalistic, swallowing other tadpoles whole.[3][9]

Defense mechanisms

Reported predators of adult Great Basin Spadefoot toads include rattlesnakes, coyotes, and owls. Predators of larva include mud turtles (Kinosternon flavescens), spotted skunks (Spilogale putarius),[10] raccoons (Procyon lotor),[11] common crows (Corvus brachyrhynchos) and snakes. Adults are able to produce skin secretions that cause allergic reactions in some humans, including a burning sensation if the secretion gets in the eyes or nose. The skin secretions also deter predators.[12]

Burrowing behavior

Great Basin spadefoot toads have adapted to life in dry habitats. Desiccation is avoided by this terrestrial amphibian through burrowing into the ground. The toad use the hard, keratinized spade on each foot to dig a burrow, where it spends long periods during cold and dry weather. The toad is able to absorb water from the surrounding soil; even as the soil becomes increasingly dry in spring and early summer months, increased concentrations of urea in the toad's body allow it to continue to suck water out of the soil through osmosis. When the summer rains arrive the Great Basin spadefoot emerges from its burrow.[3]

Morphs and adult Great Basin spadefoots normally venture from their burrows at night, when it is rainy or the night air is humid enough for dew to collect.[6] Captive spadefoots have been observed to dig shallow burrows in moist soil, then dig deeper (2 to 3 feet [0.7–1.2 m]) as soil dries at the surface. Spadefoots have been found 15 feet (4.6 m) underground in natural conditions. An individual spadefoot digs and occupies only one burrow, which it usually returns to after foraging or mating. Spadefoots do not use shrubs or other vegetation for cover while foraging.[3]

Spadefoots accumulate fat rapidly in summer. They are dormant in fall and winter, with dormancy and apparently triggered by photoperiod.[7] Spring emergence may be triggered by increased moisture in the burrow.[3] Spadefoots extend their dormancy period during drought, and can apparently remain dormant or mostly dormant for long periods of time. Fat reserves are metabolized slowly during dormancy, and females may reabsorb their eggs if spring rains do not occur.[8]

References

 This article incorporates public domain material from the United States Forest Service document "Scaphiopus intermontanus".

  1. ^ Geoffrey Hammerson (2004) Spea intermontana. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.
  2. ^ a b Stebbins, Robert C. 1985. Western reptiles and amphibians. 2nd ed. Peterson Field Guides No. 16. Boston: Houghton Mifflin Company.
  3. ^ a b c d e f g h Bragg, Arthur N. (1965). Gnomes of the night. Philadelphia: University of Pennsylvania Press
  4. ^ Frost, Darrel R. (ed.) 1985. Amphibian species of the world: a taxonomic and geographic reference. Lawrence, KS: Allen Press, Inc. ISBN 0942924118
  5. ^ Hovingh, Peter; Benton, Bob; Bornholdt, Dave (1985). "Aquatic parameters and life history observations of the Great Basin spadefoot toad in Utah". Great Basin Naturalist 45 (1): 22–30. 
  6. ^ a b c Nussbaum, Ronald A.; Brodie, Edmund D., Jr.; Storm, Robert M. (1983). Amphibians and reptiles of the Pacific Northwest. Northwest Naturalist Books. Moscow, ID: University of Idaho Press ISBN 0893010863
  7. ^ a b c Seymour, Roger S. (1973). "Energy metabolism of dormant spadefoot toads (Scaphiopus)". Copeia 3 (3): 435–445. doi:10.2307/1443107. 
  8. ^ a b Scaphiopus intermontanus. United States Forest Service. fs.fed.us
  9. ^ Whitaker, John O., Jr.; Rubin, David; Munsee, Jack R. (1977). "Observations on food habits of four species of spadefoot toads, genus Scaphiopus". Herpetologica 33: 468–475. JSTOR 3891718. 
  10. ^ Newman, R. A. (1987). "Effects of density and predation on Scaphiopus couchi tadpoles in desert ponds". Oecologia 71 (2): 301–307. doi:10.1007/BF00377299. 
  11. ^ Childs, Henry E., Jr. (1953). "Selection by predation on albino and normal spadefoot toads". Evolution 7 (3): 228–233. doi:10.2307/2405733. 
  12. ^ Waye, Heather L.; Shewchuk, Christopher H. (1995). "Scaphiopus intermontanus (Great Basin spadefoot). Production of odor". Herpetological Review 26 (2): 98–99. 

Further reading

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Names and Taxonomy

Taxonomy

Comments: Placed in the genus Scaphiopus by some authors. Hall (1998) argued against the recognition of Spea as a distinct genus, but most authors have accepted the split of Spea from Scaphiopus.

Wiens and Titus (1991) presented a phylogenetic analysis of the genus (or subgenus) Spea based on allozymic and morphological data.

Wiens and Titus (1991) found pronounced allozymic differences between small samples from populations of nominal S. intermontanus in Colorado and Oregon and suggested the possibility that two different species may be involved; further research is needed.

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.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!