Toads

Toad refers to a number of species of amphibians. A distinction is often made between frogs and toads by their appearance, prompted by the convergent adaptation among so-called toads to dry environments. For instance, toads often have leathery skin for better water retention, and a brown coloration for camouflage. Many so-called toads also burrow, which requires further adaptations. However, these adaptations merely reflect the environment a species has adapted to, and are not reliable indicators of its ancestry. Since taxonomy reflects only evolutionary relationships, any distinction between frogs and toads is irrelevant to their classification.

For instance, many members of the families Bombinatoridae, Discoglossidae, Pelobatidae, Rhinophrynidae, Scaphiopodidae, and some species from the Microhylidae family are commonly called "toads". However, the only family exclusively given the common name "toad" is Bufonidae, the "true toads". Some "true frogs" of the genus Rana have also adapted to burrowing habits, while the species within the toad genus Atelopus are conversely known by the common name "harlequin frogs".

The type species of the family Bufonidae is the Common Toad, Bufo bufo, and around it cluster a large number of species of the same genus and some smaller genera. B. bufo is a tailless amphibian of stout build with a warty skin and any animal that shares these characteristics is liable to be called a toad, regardless of its location in formal taxonomy.

Almost all toads of the family Bufonidae have two lumps on either side of the back of their head, called the parotoid glands. These glands contain a poison, which oozes out if the toad is stressed. Some, like the Cane Toad Bufo marinus, are more toxic than others. Some "psychoactive toads" such as the Colorado River Toad Bufo alvaris, have been used recreationally for the effects of the bufotoxin.

True toads
Family Bufonidae (Gray, 1825) - True Toads:
 * Adenomus (Cope, 1861)
 * Altiphrynoides (Dubois, 1987)
 * Andinophryne (Hoogmoed, 1985)
 * Ansonia (Stoliczka, 1870)
 * Atelophryniscus (McCranie, Wilson & Williams, 1989)
 * Atelopus (Duméril & Bibron, 1841)
 * Bufo (Laurenti, 1768)
 * Bufoides (Pillai & Yazdani, 1973)
 * Capensibufo (Grandison, 1980)
 * Churamiti (Channing & Stanley, 2002)
 * Crepidophryne (Cope, 1889)
 * Dendrophryniscus (Jiménez de la Espada, 1871)
 * Didynamipus (Andersson, 1903)
 * Frostius (Cannatella, 1986)
 * Laurenhryne (Tihen, 1960)
 * Leptophryne (Fitzinger, 1843)
 * Melanophryniscus (Gallardo, 1961)
 * Mertensophryne (Tihen, 1960)
 * Metaphryniscus (Señaris, Ayarzagüena & Gorzula, 1994)
 * Nectophryne (Buchholz & Peters, 1875)
 * Nectophrynoides (Noble, 1926)
 * Nimbaphrynoides (Dubois, 1987)
 * Oreophrynella (Boulenger, 1895)
 * Osornophryne (Ruiz-Carranza & Hernández-Camacho, 1976)
 * Parapelophryne (Fei, Ye & Jiang, 2003)
 * Pedostibes (Günther, 1876)
 * Pelophryne (Barbour, 1938)
 * Pseudobufo (Tschudi, 1838)
 * Rhamphophryne (Trueb, 1971)
 * Schismaderma (Smith, 1849)
 * Spinophrynoides (Dubois, 1987)
 * Stephopaedes (Channing, 1979)
 * Truebella (Graybeal & Cannatella, 1995)
 * Werneria (Poche, 1903)
 * Wolterstorffina (Mertens, 1939)

Other toad families
Family Bombinatoridae (Gray, 1825) - Fire-bellied Toads:
 * Barbourula (Taylor & Noble, 1924)
 * Bombina (Oken, 1816)

Family Brachyctpoephalidae (Günther, 1858) - Shield Toads:
 * Brachycephalus (Fitzinger, 1826)

Family Discoglossidae (Günther, 1858)
 * Alytes (Wagler, 1830) - Midwife Toad

Family Microhylidae (Günther, 1858)
 * Subfamily Microhylinae - Narrowmouthed Toads:
 * Gastrophryne (Fitzinger, 1843)

Family Pelobatidae (Bonaparte, 1850) - European Spadefoot Toads:
 * Pelobates (Wagler, 1830)

Family Scaphiopodidae (Cope, 1865) - North American Spadefoot Toads:
 * Scaphiopus (Holbrook, 1836)
 * Spea (Cope, 1866)

Family Rhinophrynidae (Günther, 1859) - Burrowing Toads:
 * Rhinophrynus (Duméril and Bibron, 1841)

Other
The Moche people of ancient Peru worshipped animals and often depicted toads in their art.

To Vietnamese people, toad is the uncle of the Sky. According to a Vietnamese ancient story, whenever toads grind their teeth, it is going to rain.

Superstition
It is commonly believed that if you touch a toad or if it urinates on you, that you will become infected with warts. This is in fact false. Warts are caused by an internal viral infection. Therefore, it is impossible for warts to be caused by an external source, such as a toad. In addition, the paratoidal glands, which toads use to secrete poison for protection, are often mistaken for warts. It is likely this misconception that led to the 'toads cause warts' myth.

Books

 * Belden, L. K., Wildy, E. L., Hatch, A. C., & Blaustein, A. R. (2000). Juvenile western toads, Bufo boreas, avoid chemical cues of snakes fed juvenile, but not larval, conspecifics: Animal Behaviour Vol 59(4) Apr 2000, 871-875.
 * Belden, L. K., Wildy, E. L., Hatch, A. C., & Blaustein, A. R. (2000). Juvenile western toads, Bufo boreas, avoid chemical cues of snakes fed juvenile, but not larval, conspecifics: Animal Behaviour Vol 59(4) Apr 2000, 871-875.

Papers

 * Bisazza, A., Cantalupo, C., Robins, A., Rogers, L. J., & Vallortigara, G. (1997). Pawedness and motor asymmetries in toads: Laterality: Asymmetries of Body, Brain and Cognition Vol 2(1) 1997, 49-64.
 * Bosch, J., & Boyero, L. (2004). Reproductive stage and phonotactic preferences of female midwife toads (Alytes cisternasii): Behavioral Ecology and Sociobiology Vol 55(3) Jan 2004, 251-256.
 * Bosch, J., & Marquez, R. (2000). Tympanum fluctuating asymmetry, body size and mate choice in female midwife toads (Alytes obstetricans): Behaviour Vol 137(9) Sep 2000, 1211-1222.
 * Byrne, P. G., & Keogh, J. S. (2007). Terrestrial toadlets use chemosignals to recognize conspecifics, locate mates and strategically adjust calling behaviour: Animal Behaviour Vol 74(5) Nov 2007, 1155-1162.
 * Crawford, F. T., & Langdon, J. W. (1966). Escape and avoidance responding in the toad: Psychonomic Science Vol 6(3) 1966, 115-116.
 * Crespi, E. J., & Denver, R. J. (2004). Ontogeny of corticotropin-releasing factor effects on locomotion and foraging in the Western spadefoot toad (Spea hammondii): Hormones and Behavior Vol 46(4) Nov 2004, 399-410.
 * Daneri, M. F., Papini, M. R., & Muzio, R. N. (2007). Common toads (Bufo arenarum) learn to anticipate and avoid hypertonic saline solutions: Journal of Comparative Psychology Vol 121(4) Nov 2007, 419-427.
 * Devito, J., Chivers, D. P., Kiesecker, J. M., Marco, A., Wildy, E. L., & Blaustein, A. R. (1998). The effects of snake predation on metamorphosis of western toads Bufo boreas (Amphibia, bufonidae): Ethology Vol 104(3) Mar 1998, 185-193.
 * Diego-Rasilla, F. J., & Luengo, R. M. (2004). Heterospecific call recognition and phonotaxis in the orientation behavior of the marbled newt, Triturus marmoratus: Behavioral Ecology and Sociobiology Vol 55(6) Apr 2004, 556-560.
 * Dyson, M. L., Bush, S. L., & Halliday, T. R. (1998). Phonotaxis by female Majorcan midwife toads, Alytes muletensis: Behaviour Vol 135(2) Mar 1998, 213-230.
 * Ferguson, D. E., & Landreth, H. F. (1966). Celestial orientation of Fowler's toad, Bufo fowleri: Behaviour 26(1-2) 1966, 105-123.
 * Forester, D. C., & Thompson, K. J. (1998). Gauntlet behaviour as a male sexual tactic in the American toad (Amphibia: Bufonidae): Behaviour Vol 135(2) Mar 1998, 99-119.
 * Ingle, D. (1998). Perceptual constancies in lower vertebrates. New York, NY: Cambridge University Press.
 * Lea, J., Dyson, M., & Halliday, T. (2001). Calling by male midwife toads stimulates females to maintain reproductive condition: Animal Behaviour Vol 61(2) Feb 2001, 373-377.
 * Leary, C. J. (2001). Evidence of convergent character displacement in release vocalizations of Bufo fowleri and Bufo terrestris (Anura; Bufonidae): Animal Behaviour Vol 61(2) Feb 2001, 431-438.
 * Leary, C. J., Fox, D. J., Shepard, D. B., & Garcia, A. M. (2005). Body size, age, growth and alternative mating tactics in toads: Satellite males are smaller but not younger than calling males: Animal Behaviour Vol 70(3) Sep 2005, 663-671.
 * Leary, C. J., Garcia, A. M., & Knapp, R. (2006). Elevated corticosterone levels elicit non-calling mating tactics in male toads independently of changes in circulating androgens: Hormones and Behavior Vol 49(4) Apr 2006, 425-432.
 * Leary, C. J., Jessop, T. S., Garcia, A. M., & Knapp, R. (2004). Steroid hormone profiles and relative body condition of calling and satellite toads: Implications for proximate regulation of behavior in anurans: Behavioral Ecology Vol 15(2) Mar 2004, 313-320.
 * Malashichev, Y. B., & Nikitina, N. G. (2002). Preferential limb use in relation to epicoracoid overlap in the shoulder girdle of toads: Laterality: Asymmetries of Body, Brain and Cognition Vol 7(1) Jan 2002, 1-18.
 * Marquez, R., Bosch, J., & Eekhout, X. (2008). Intensity of female preference quantified through playback setpoints: Call frequency versus call rate in midwife toads: Animal Behaviour Vol 75(1) Jan 2008, 159-166.
 * McConville, J., Sterritt, L., & Laming, P. R. (2006). Behavioural responses to electrical and visual stimulation of the toad tectum: Behavioural Brain Research Vol 170(1) Jun 2006, 15-22.
 * Mirza, R. S., Ferrari, M. C. O., Kiesecker, J. M., & Chivers, D. P. (2006). Responses of American toad tadpoles to predation cues: Behavioural response thresholds, threat-sensitivity and acquired predation recognition: Behaviour Vol 143(7) Jul 2006, 877-889.
 * Muzio, R. N., Ruetti, E., & Papini, M. R. (2006). Determinants of instrumental extinction in terrestrial toads (Bufo arenarum): Learning and Motivation Vol 37(4) Nov 2006, 346-356.
 * Pfennig, K. S. (2007). Facultative mate choice drives adaptive hybridization: Science Vol 318(5852) Nov 2007, 965-967.
 * Pfennig, K. S., Rapa, K., & McNutt, R. (2000). Evolution of male mating behavior: Male spadefoot toads preferentially associate with conspecific males: Behavioral Ecology and Sociobiology Vol 48(1) Jun 2000, 69-74.
 * Pupin, F., Sacchi, R., Gentilli, A., Galeotti, P., & Fasola, M. (2007). Discrimination of toad calls by smooth newts: Support for the heterospecific attraction hypothesis: Animal Behaviour Vol 74(6) Dec 2007, 1683-1690.
 * Riley, C. F. C. (1913). Responses of young toads to light and contact: Journal of Animal Behavior Vol 3(3) May-Jun 1913, 179-214.
 * Robins, A., & Rogers, L. J. (2004). Lateralized prey-catching responses in the cane toad, Bufo marinus: Analysis of complex visual stimuli: Animal Behaviour Vol 68(4) Oct 2004, 767-775.
 * Robins, A., & Rogers, L. J. (2006). Complementary and lateralized forms of processing in Bufo marinus for novel and familiar prey: Neurobiology of Learning and Memory Vol 86(2) Sep 2006, 214-227.
 * Sovrano, V. A. (2007). A note on asymmetric use of the forelimbs during feeding in the European green toad (Bufo viridis): Laterality: Asymmetries of Body, Brain and Cognition Vol 12(5) Sep 2007, 458-463.
 * Spieler, M., & Linsenmair, K. E. (1999). Aggregation behaviour of Bufo maculatus tadpoles as an antipredator mechanism: Ethology Vol 105(8) Aug 1999, 665-686.
 * Vasquez, T., & Pfennig, K. S. (2007). Looking on the bright side: Females prefer coloration indicative of male size and condition in the sexually dichromatic spadefoot toad, Scaphiopus couchii: Behavioral Ecology and Sociobiology Vol 62(1) Nov 2007, 127-135.