Black toad

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Black toad
Anaxyrus exsul 001.jpg
Status TNC G1.svg
Critically Imperiled  (NatureServe) [2]
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Bufonidae
Genus: Anaxyrus
Species:
A. exsul
Binomial name
Anaxyrus exsul
(Myers, 1942)
Anaxyrus exsul range map.png
Synonyms

Bufo exsulMyers, 1942

The black toad (Anaxyrus exsul), also known as the Inyo toad or Deep Springs toad, is a true toad that lives only in scattered oases in the Deep Springs Valley of Inyo County, California. [1] [3] [4] In fact, its original scientific name, Bufo exsul, means "exiled toad," which refers to its species' isolation in a tiny spot in the high desert wilderness of the Californian Great Basin. [4]

Contents

Description

The toad's black skin is covered in white and tan speckles and it sports a white midline down its spine from head to rump. Adults are approximately 5 centimetres (2.0 in) in length. They are active during the warmer months and overwinter underground near their native springs. This species walks rather than hops, and never strays far from water. Male black toads do not have vocal sacs and do not make a real advertisement call, but rather a small chirping noise as a territorial call around other males; much like its close relative the western toad (Anaxyrus boreas).

Conservation status

The habitat of the black toad is relatively intact, however it is still considered a vulnerable species because although it is abundant within its habitat, the black toad has a very limited range. [1] Deep Springs College continues a program to care for the wild population of this species, and owns much of the land where its habitat is found. [5] Livestock grazing has occurred in much of the toad habitat for more than one hundred years, and grazing, vegetation management, and irrigation have been suggested as possibly increasing the suitable habitat for the species, which breeds in otherwise comparatively rare open water. As noted in the IUCN Red List, [1] the population of this species was reported to be more or less stable in the early 1970s, [6] [7] and no significant change was reported in 1990 or 1999. [8] [9] The population at Antelope Springs was once reported to have died out, [10] but was found by researchers in 2003, [9] and is now apparently thriving where vegetation has been maintained in a suitable state. In 1977 it was estimated that there were more than 80,000 individuals in the population. [11]

The toad's primary habitat is watercourses, irrigation ditches, and marshes (grass, sedge, dwarf bulrush, and watercress) formed by waterflow from springs, surrounded by cold desert steppe. Adults are more aquatic than other toad species in California, and breed in shallow marsh and pond waters. The toads retreat to rodent burrows or other refuges in winter. [12] At present, there do not appear to be any major threats to this species. However, potential future threats might include habitat destruction from changes in irrigation schemes or other factors resulting in water table alteration, well-intentioned but non-scientifically based conservation efforts, [9] changes in water availability, recreational vehicle use, collection by humans, changes in grazing regimes and predation by introduced fish. [1] Other desert toads in nearby areas have done well, and even thrived, with more active management. [13] Black toad adults prefer habitats with short plant cover and unobstructed access to still or slowly flowing water. [12] In recent years, fencing some springs to exclude cattle has resulted in an overgrowth of vegetation requiring hand cutting to keep the habitat accessible for toads. The toads have been able to maintain a fairly stable population regardless of changes in agriculture and grazing practices over the past 20 years. [9]

The black toad was federally listed as a species "threatened with extinction" in 1967 by the authority of the Endangered Species Preservation Act of 1966. [14] Following the passage of the Endangered Species Act of 1973 (ESA), the species was proposed for a threatened status under the replacement legislation and critical habitat was outlined. [15] However, with the passage of amendments to the ESA in 1978, these materials were invalidated and the window of time for the ESA listing proposal to be finalized lapsed in 1980. [16] At present the black toad is designated as a "Fully Protected" and "Threatened" species of California at the state level only. [17] [18]

Related Research Articles

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<span class="mw-page-title-main">American toad</span> Species of amphibian

The American toad is a common species of toad found throughout Canada and the eastern United States. It is divided into three subspecies: the eastern American toad, the dwarf American toad and the rare Hudson Bay toad. Recent taxonomic treatments place this species in the genus Anaxyrus instead of Bufo.

<span class="mw-page-title-main">Houston toad</span> Species of amphibian endemic to Texas, US

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<span class="mw-page-title-main">Western toad</span> Species of amphibian

The western toad is a large toad species, between 5.6 and 13 cm long, native to western North America. A. boreas is frequently encountered during the wet season on roads, or near water at other times. It can jump a considerable distance for a toad. Breeding occurs between March and July in mountainous areas, and as early as January in lower-elevation regions. The female lays up to 17,000 eggs stuck together in strings that adhere to vegetation and other objects along water edges.

<span class="mw-page-title-main">Arroyo toad</span> Species of amphibian

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The Wyoming toad or Baxter's toad is an extremely rare amphibian that exists only in captivity and within Mortenson Lake National Wildlife Refuge in Wyoming in the United States. The Wyoming toad was listed as an endangered species in 1984, and listed as extinct in the wild since 1991. As with ferrets at the Tom Thorne and Beth Williams Wildlife Research Center at Sybille in Wheatland, Wyoming, the effort to save the Wyoming toad has been a cooperative effort among state and federal agencies and private landowners. The Wyoming toad was common from the 1950s through the early 1970s, but its distribution was limited to the Laramie Basin in Albany County. The population crashed around 1975 and was extremely low by 1980. The Wyoming toad was federally listed as endangered in January 1984. To prevent extinction, a captive-breeding program began in 1989 at the Thorne Williams Unit that produced enough offspring in its first few years to supply seven zoos, and in 1998 the Saratoga National Fish Hatchery received captive-breeding stock. Nearly 46,000 offspring were produced at the Thorne Williams Unit from 1995 until 2006, when the remaining captive stock was moved to the Red Buttes Environmental Biology Laboratory south of Laramie, and then released back into the wild. Before the sharp declines occurred, this toad was classified as a subspecies of the Canadian toad.

<span class="mw-page-title-main">Southern toad</span> Species of amphibian

The southern toad is a true toad native to the southeastern United States, from eastern Louisiana and southeastern Virginia south to Florida. It often lives in areas with sandy soils. It is nocturnal and spends the day in a burrow. Its coloring is usually brown but can be red, gray, or black. It is approximately 8 cm (3 inches) long.

<span class="mw-page-title-main">Woodhouse's toad</span> Species of amphibian

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<i>Anaxyrus fowleri</i> Species of amphibian

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<span class="mw-page-title-main">Great Plains toad</span> Species of amphibian

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<span class="mw-page-title-main">Yosemite toad</span> Species of amphibian

The Yosemite toad is a species of true toad in the family Bufonidae. Endemic to the Sierra Nevada of California, the species ranges from the Alpine County to Fresno County. Yosemite toads are only found in the montane to subalpine elevational zone of 1,950–3,445 m (6,398–11,302 ft) asl. The Yosemite toad is similar to the nearby Western toad, but in many ways adapted to a high elevation lifestyle. It was initially described during the Grinnell Survey of California, by an undergraduate student of Joseph Grinnell named Charles Camp.

<span class="mw-page-title-main">Arizona toad</span> Species of amphibian

The Arizona toad is a species of toad in the family Bufonidae. It is endemic to the south-western United States, where its natural habitats are temperate lowland forests, rivers and streams, swamps, freshwater marshes, freshwater springs, ponds, open excavations, irrigated land, and seasonally flooded agricultural land.

<span class="mw-page-title-main">Amargosa toad</span> Species of amphibian

The Amargosa toad is a species of toad in the family Bufonidae. It was at one time considered to be a subspecies of the western toad. It is threatened by habitat loss and is classified by the IUCN as being "Critically endangered".

<span class="mw-page-title-main">Oak toad</span> Species of amphibian

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<span class="mw-page-title-main">Dixie Valley toad</span> Species of amphibian

The Dixie Valley toad is a species of toad in the family Bufonidae. It is endemic to Churchill County in the state of Nevada in the United States. It was the first new toad species to be described from the United States since the description of the now-extinct in the wild Wyoming toad about 49 years prior.

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References

  1. 1 2 3 4 5 Geoffrey Hammerson (2004). "Anaxyrus exsul". IUCN Red List of Threatened Species . 2004: e.T3169A9647112. doi: 10.2305/IUCN.UK.2004.RLTS.T3169A9647112.en . Retrieved 20 November 2021.
  2. ↑ "NatureServe Explorer 2.0". explorer.natureserve.org. Retrieved 6 June 2022.
  3. ↑ Frost, Darrel R. (2015). "Anaxyrus exsul (Myers, 1942)". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 3 January 2016.
  4. 1 2 Nafis, Gary (2000–2015). "Bufo exsul - Black Toad". A Guide to the Amphibians and Reptiles of California. Archived from the original on 31 August 2015. Retrieved 3 January 2016.
  5. ↑ Sahagún, Louis (8 April 2021). "When rare California toads get thirsty for love, this tiny college helps set the mood". Los Angeles Times. Retrieved 8 May 2021.
  6. ↑ Bury, R.B., Dodd, Jr., C.K. and Fellers, G.M. 1980. Conservation of the Amphibia of the United States: a review. Resource Publication: 1-34.
  7. ↑ Schuierer, F.W. 1972. The current status of the endangered species Bufo exsul Myers, Deep Springs Valley, Inyo County, California. Herpetological Review 4: 81-82.
  8. ↑ California Department of Fish and Game (CDF&G). 1990. 1989 annual report on the status of California's state listed threatened and endangered plants and animals. California Department of Fish and Game
  9. 1 2 3 4 Murphy, J.F., Simandle, E.T. and Becker, D.E. 2003. Population status and conservation of the black toad, Bufo exsul. Southwestern Naturalist 48: 54-60.
  10. ↑ Stebbins, R.C. A Field Guide to Western Reptiles and Amphibians. Second Edition. Houghton Mifflin Company, Boston, Massachusetts.
  11. ↑ Sherman, C.K. 1980. A comparison of the natural history and mating system of two anurans: Yosemite toads (Bufo canorus) and black toads (Bufo exsul). Ph.D. Dissertation, University of Michigan, Ann Arbor, Michigan.
  12. 1 2 Schuierer, F. W., and S. C. Anderson. 1990. Population status of Bufo exsul Myers. Herpetological Review 21:57.
  13. ↑ Hamilton, Jon (10 November 2010). "All Hopped Up: Town Unites For Toad Revival". npr.org/. NPR. Retrieved 16 January 2011.
  14. ↑ 32 FR 4001
  15. ↑ 42 FR 13567
  16. ↑ 45 FR 5782
  17. ↑ "Amphibian Conservation - Black Toad". CDFW Inland Deserts Region (Region 6). California Department of Fish and Wildlife. Retrieved 12 April 2023.
  18. ↑ "Black toad (Bufo exsul)". Environmental Conservation Online System. U.S. Fish & Wildlife Service. Retrieved 12 April 2023.

Further reading

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