Arroyo Toad (23789477236)
   HOME

TheInfoList



OR:

The arroyo toad (''Anaxyrus californicus'') is a species of
true toad A true toad is any member of the family Bufonidae, in the order Anura (frogs and toads). This is the only family of anurans in which all members are known as toads, although some may be called frogs (such as harlequin frogs). The bufonids now ...
s in the family
Bufonidae {{Cat main, Toad This category contains both species commonly called toads, and the true toads from the family Bufonidae {{Cat main, Toad This category contains both species commonly called toads, and the true toads from the family Bufonidae {{Cat m ...
, endemic to
California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, U.S. and
Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
state, Mexico. It is currently classified as an
Endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
on the
IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
of Threatened Species because of
habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
.


Description

The arroyo toad is a stocky, blunt-nosed, warty-skinned species of
toad Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. A distinction between frogs and toads is not made in scientif ...
, long. It has horizontal pupils, and is greenish, grey or salmon on the dorsum with a light-colored stripe across the head and eyelids. It has light sacral and mid-dorsal patches, large, oval and widely separated
parotoid gland The parotoid gland (alternatively, paratoid gland) is an external skin gland on the back, neck, and shoulder of toads and some frogs and salamanders. It can secrete a number of milky alkaloid substances (depending on the species) known collective ...
s, and weak or absent cranial crests. The juvenile of this species are ashy-white, olive or salmon on the dorsal side, with or without black spotting. It has red-tipped tubercles on its back.


Distribution and habitat

The arroyo toad prefers sandy or cobbly washes with swift currents and associated upland and
riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...
habitats, in
Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...
from
Santa Barbara County Santa Barbara County, California, officially the County of Santa Barbara, is located in Southern California. As of the 2020 census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa Maria. Santa Barba ...
south into northwestern
Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
. An
arroyo Arroyo often refers to: * Arroyo (creek), an intermittently dry creek Arroyo may also refer to: People * Arroyo (surname) Places United States ;California * Arroyo Burro Beach, a public beach park in Santa Barbara County, California * Arroyo ...
, in the desert called a
wash WASH (or Watsan, WaSH) is an acronym that stands for "water, sanitation and hygiene". It is used widely by non-governmental organizations and aid agencies in developing countries. The purposes of providing access to WASH services include achievin ...
, is a predominantly dry creek or river bed. It fills and flows after sufficient rain, but only temporarily during specific seasons. The arroyo toad inhabits these areas alongside creeks and rivers with shallow pebble-like rocks near sandy terrains. Adults take refuge into the sandy soil for protection and shelter and for deposition of eggs. Areas with very little to no vegetation are the primary target.


Behavior

The arroyo toad is nocturnal, spending most of the day underground with exception to mating season. During the mating season may be found during the day along the shallows of a pond. It travels by quickly hopping, as opposed to walking or striding. When hunting for food the toad lunges towards the targets, usually ants, and extends its large sticky tongue to trap and consume them. During the dry season the arroyo toad goes into a state of
hibernation Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most ...
called aestivation to prevent dehydration. This dormant state normally takes place within the soil or clay-like sand and is from August to January.


Reproduction

The breeding season of the arroyo toad revolves around the months of late winter and early spring after seasonal rains. The male toad will choose a spot near a river or water bank where he will make mating calls to attract a female toad. They mate in an
amplexus Amplexus (Latin "embrace") is a type of mating behavior exhibited by some externally fertilizing species (chiefly amphibians and horseshoe crabs) in which a male grasps a female with his front legs as part of the mating process, and at the same ...
position, and the female toad returns to the location to lay her eggs by the water. The eggs are laid in a two-row formation with an average of 4,700 eggs. The placement of the eggs by the water is very crucial due to the water flow: if some of the eggs are too far from hydration they will dry up and die; eggs can also drop into the depth of the water and be eaten by predators. The eggs that survive hatch in between four and six days.


Diet

Once the eggs hatch, the larvae feed on microbes found in the sand by the water where they hatch. For the most part, young arroyo toads feed on ants and other small insects. When they grow their diet changes to include small beetles. The diet of an adult toad usually consists of caterpillars, moths, crickets, snails, and in some instances eggs and larvae of other Arroyo toads.


Defense mechanisms

The toad defends itself with a toxin found on its skin. The toxin is released from the
parotoid gland The parotoid gland (alternatively, paratoid gland) is an external skin gland on the back, neck, and shoulder of toads and some frogs and salamanders. It can secrete a number of milky alkaloid substances (depending on the species) known collective ...
s which can be identified as pale spots found towards the head. The main component found in the venom is called
bufotoxin Bufotoxins are a family of toxic steroid lactones or substituted tryptamines of which some may or may not be toxic. They occur in the parotoid glands, skin, and poison of many toads ( genus ''Bufo'') and other amphibians, and in some plants and ...
. All of the venom found on the toad's skin is enough to cause serious symptoms or even death in the attacker. Although some natural predators have built an immunity and regularly feed on the toads, their toxin should not be underestimated. If a human comes in contact with the toad's skin symptoms include: serious irritation and pain to the throat, eyes, nose, and mouth, cardiovascular and respiratory systems, seizures and paralysis, vomiting, hallucinations or even death. There is no anti-venom and treatment varies based on the symptoms exhibited. Another method of defense is hiding in vegetation or underwater from attackers.


Predators

The arroyo toad is fairly cryptic, but often vulnerable to a variety of predators. Eggs and larvae are susceptible to being preyed on by fish, other species of frogs (not excluding adult forms of the Arroyo toad), birds, snakes, and insects that inhabit the waters where the eggs and larvae are developing. Adult arroyo toads are also vulnerable to predators such as American Bullfrogs and garter snakes. Although they may escape, they have a high likeliness of dying from wounds caused by their attackers. The American Bullfrog has a tendency to prey on males during their mating calls, and will attack toads while they are in amplex thereby preventing reproduction rates in the population. This has a great influence on the decrease in the species population number.


Conservation

The total estimated breeding population is less than 3,000 individuals. In 1994 when the species was listed, only six of the 22 extant populations south of Ventura were known to contain more than a dozen adults. It has been extirpated from an estimated 75% of its former range in the U.S. The most important threats to the arroyo toad stem from human activities. These activities include encroachment by agriculture, construction of roads, off-road vehicle use, grazing by livestock and mining. All can result in substantial
habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
and/or alteration of river hydrology. Other smaller threats are due to introduced non−native predators such as
bullfrog ''Bullfrog'' is a common English language term to refer to large, aggressive frogs, regardless of species. Examples of bullfrogs include: Frog species America *Helmeted water toad (''Calyptocephalella gayi''), endemic to Chile *American bullfro ...
s and predatory fish, non−native
invasive plant An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
s, drought, wildfire and
wildfire suppression Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated ...
, unseasonal water releases from dams, and light and noise pollution from adjacent developments. The arroyo toad has been the subject of litigation related to its conservation status. In 2000, developer Rancher Viejo, which wished to build on a site that the toads used as a habitat, sued the
Secretary of the Interior Secretary of the Interior may refer to: * Secretary of the Interior (Mexico) * Interior Secretary of Pakistan * Secretary of the Interior and Local Government (Philippines) * United States Secretary of the Interior See also

*Interior ministry ...
over whether the Department was constitutionally authorized to apply the
Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...
to prevent the development in order to protect a species that never crossed state lines. The developer's challenge to the law failed, but in his dissent to the ruling then-Judge and later- Chief Justice
John Roberts John Glover Roberts Jr. (born January 27, 1955) is an American lawyer and jurist who has served as the 17th chief justice of the United States since 2005. Roberts has authored the majority opinion in several landmark cases, including ''Nati ...
famously expressed his puzzlement that "regulating the taking of a hapless toad that, for reasons of his own, lives its entire life in California constitutes regulating ' commerce...among the several states'." On March 27, 2014, the Department of Fish and Wildlife recommended the arroyo toad's status be downgraded from Endangered to
Threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensat ...
. The agency stated that the arroyo toad still faces "significant threats", in particular operation of dams and water diversions, urban development, introduced predator species, and drought. However, they felt that conditions had improved, saying, "The overall magnitude of threats impacting the arroyo toad has decreased since the time of listing, due in part to implementation of conservation and management actions."


References


Further reading


Biologicaldiversity.org: Arroyo toad (''Anaxyrus californicus'')
*Mitrovich, Milan J., et al. "Habitat Use and Movement of the Endangered Arroyo Toad (Anaxyrus californicus) in Coastal Southern California." Journal of Herpetology 45.3 (2011): 319-328. *Pauly, G. B., D. M. Hillis, and D. C. Cannatella. (2004) The history of a Nearctic colonization: Molecular phylogenetics and biogeography of the Nearctic toads (''Bufo''). ''Evolution'' ''58'': 2517–2535. *Sahagun, L

''
Los Angeles Times The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the Un ...
'' August 26, 2011. Retrieved August 30, 2011. *Miller, David AW, et al. "Joint estimation of habitat dynamics and species interactions: disturbance reduces co‐occurrence of non‐native predators with an endangered toad." Journal of Animal Ecology 81.6 (2012): 1288-1297. *Blumm, Michael C., and George A. Kimbrell. "Flies, Wolves, Spiders, Toads, and the Constitutionality of the Endangered Species Act's Take Provision."Environmental Law 34 (2004): 309. *Griffin, Paul C., and Ted J. Case. "Terrestrial habitat preferences of adult arroyo southwestern toads." The Journal of wildlife management (2001): 633-644.


External links

* * {{Taxonbar, from=Q28030852 Anaxyrus Amphibians of Mexico Amphibians of the United States Fauna of the California chaparral and woodlands Natural history of Baja California Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Endangered fauna of California ~ Amphibians described in 1915 ESA endangered species Species endangered by habitat loss