TheColorado River toad (Incilius alvarius), also known as theSonoran Desert toad, is atoad species found in northwesternMexico and thesouthwestern United States. It is well known for its ability toexudetoxins from glands within its skin that havepsychoactive properties.
The Colorado River toad can grow to about 190 millimetres (7.5 in) long and is the largest toad in the United States apart from the non-nativecane toad (Rhinella marina). It has a smooth, leathery skin and is olive green or mottled brown in color. Just behind the large golden eye with horizontal pupil is a bulging kidney-shapedparotoid gland. Below this is a large circular pale green area which is thetympanum or ear drum. By the corner of the mouth there is a white wart and there are white glands on the legs. All these glands produce toxic secretions. Its call is described as, "a weak, low-pitched toot, lasting less than a second."[4]
Dogs (Canis familiaris) that have attacked toads have suffered paralysis or even death.Raccoons (Procyon lotor) have learned to pull a toad away from a pond by the back leg, turn it on its back and start feeding on its belly, a strategy that keeps the raccoon well away from the poison glands.[5] Unlike other vertebrates, this amphibian obtains water mostly byosmotic absorption across its abdomen. Toads in the family Bufonidae have a region of skin known as "the seat patch", which extends from mid abdomen to the hind legs and is specialized for rapid rehydration. Most of the rehydration is done through absorption of water from small pools or wet objects.[6]
In theUnited States, the Colorado River toad is found in the lowerColorado River and theGila River catchment areas, in extreme southwesternNew Mexico and much of southernArizona. It is considered possiblyextirpated fromCalifornia.[7] In Mexico, the toad is found in the states ofSonora,Sinaloa, andChihuahua. It lives in bothdesert andsemi-arid areas throughout its range. It issemiaquatic and is often found in streams, near springs, incanals and drainage ditches, and under water troughs.[5] The Colorado River toad is known to breed in artificial water bodies (e.g., flood control impoundments, reservoirs) and as a result, the distributions and breeding habitats of these species may have been recently altered in south-central Arizona.[8] It often makes its home in rodent burrows and isnocturnal.
The Colorado River toad issympatric with thespadefoot toad (Scaphiopus spp.),Great Plains toad (Anaxyrus cognatus),red-spotted toad (Anaxyrus punctatus), andWoodhouse's toad (Anaxyrus woodhousei). Like many other toads, they are active foragers and feed on invertebrates, lizards, small mammals, and amphibians. The most active season for toads is May–September, due to greater rainfalls (needed for breeding purposes). The age ofI. alvarius individuals in a population at Adobe Dam inMaricopa County, Arizona, ranged from 2 to 4 years; other species of toad have a lifespan of 4 to 5 years.[9] The taxonomic affinities ofI. alvarius remain unclear, but immunologically, it is similarly close to theboreas andvalliceps groups.[10]
The breeding season starts in July, when the rainy season begins, and can last up to August. Normally, 1–3 days after the rain is when toads begin to lay eggs in ponds, slow-moving streams, temporary pools or man-made structures that hold water. Eggs are 1.6 mm in diameter, 5–7 mm apart, and encased in a long single tube of jelly with a loose but distinct outline. The female toad can lay up to 8,000 eggs.[11]
The toad's primary defense system is glands that producea poison that may be potent enough to kill a grown dog.[12] Theseparotoid glands also produce5-methoxy-dimethyltryptamine (5-MeO-DMT)[13] andbufotenin (which is named after theBufo genus of toads); both of these chemicals belong to the family of hallucinogenictryptamines. Bufotenin can be toxic.[14]
When vaporized, a single deep inhalation of the poison produces strong psychoactive effects within 15 seconds.[15] After inhalation, the user usually experiences a warm sensation, euphoria, and strong visual and auditory hallucinations, due to 5-MeO-DMT's high affinity for the5-HT2 and5-HT1Aserotonin receptor subtypes.[16]
Bufotenin is a chemical constituent in the secretions and eggs of several species of toads belonging to the genusBufo, but the Colorado River toad (Incillius alvarius) is the only toad species in which bufotenin is present in large enough quantities for a psychoactive effect. Extracts of toad secretion, containing bufotenin and otherbioactive compounds, have been used in some traditional medicines such asch’an su (probably derived fromBufo gargarizans), which has been used medicinally for centuries in China,[17] as a herbal remedy often illegally imported to the USA that can be prepared as a tea.[18]
The toad was "recurrently depicted inMesoamerican art",[19] which some authors have interpreted as indicating that the effects of ingestingBufo secretions have been known in Mesoamerica for many years; however, others doubt that this art provides sufficientethnohistorical evidence to support the claim.[17]
In addition to bufotenin,Bufo secretions also containdigoxin-likecardiac glycosides, and ingestion of the poison can be fatal. Ingestion ofBufo toad toxins and eggs by humans has resulted in several reported cases of poisoning,[20][21][22] some of which resulted in death.[22][23][24] The first reported death associated with the ingestion of ch'an su was that of a young woman who consumed it as a prescribed (by a Chinese herbalist) Chinese herbal remedy mixed into a tea (an approximately 100ml bowl). Immediately upon ingesting the ch'an tea, the woman experienced vomiting, difficulty breathing, and gastric tenderness, which spurred her husband to take her to the emergency room, where she died two and a half hours after drinking the tea.[25]
Contemporary reports indicate that bufotenin-containing toad toxins have been used as astreet drug; that is, as a supposedaphrodisiac,[26] ingested orally in the form ofch’an su,[22] and as a psychedelic, by smoking or orally ingestingBufo toad secretion or driedBufo skins. The use ofchan'su andlove stone (a related toad toxin preparation used as an aphrodisiac in theWest Indies) has resulted in several cases of poisoning and at least one death.[22][27] The practice of orally ingesting toad secretions has been referred to in popular culture and in the scientific literature as "toad licking" and has drawn media attention.[28] Ken Nelson (under the pseudonym of Albert Most) published a booklet (illustrated by Gail Patterson) titledBufo alvarius: The Psychedelic Toad of the Sonoran Desert[29][30][31] in 1984 which explained how to extract and smoke the secretions.
On October 31, 2022 the United StatesNational Park Service posted a warning onFacebook that people should not handle or lick the toad.[37][38][39] Despite the warning's wide coverage in media, the post was made humorously and the Park Service has no records of people licking or otherwise harassing the toads in parks.[40]
A substance found among the toxins the toad excretes when it is threatened,5-MeO-DMT, is often dried into crystals and smoked. It is considered illegal in the United States, and categorized as a Schedule 1 substance, though law enforcement is increasingly less likely to enforce the laws with its growing popularity.[41]
The toads received national attention in 1994 afterThe New York Times Magazine published an article about a California teacher who became the first person to be arrested for possessing secretions of the toads.[42][43] Bufotenin had been outlawed in California since 1970.[44]
In November 2007, a man inKansas City, Missouri, was discovered with anI. alvarius toad in his possession, and charged with possession of a controlled substance after they determined he intended to use its secretions for recreational purposes.[45][46] In Arizona, one may legally bag up to 10 toads with a fishing license, but it could constitute a criminal violation if it can be shown that one is in possession of this toad with the intent to smoke its secretions.[47]
None of the U.S. states in whichI. alvarius is or was indigenous – California, Arizona, and New Mexico – legally allows a person to remove the toad from the state. For example, theArizona Game and Fish Department is clear about the law in Arizona: "An individual shall not...export any live wildlife from the state; 3. Transport, possess, offer for sale, sell, sell as live bait, trade, give away, purchase, rent, lease, display, exhibit, propagate...within the state."[47]
Due to the rising popularity in collecting this toad, compounded with other threats such as motorists running over them, and predators such as raccoons eating them, U.S. states such as New Mexico and California have listed them as "threatened" and collectingI. alvarius is unlawful in those states.[48][49][50] Collecting these toads is thought to cause stress to them, in particular during the process of "milking" where collectors rub the toads under the chin to cause it to secrete the poison in the form of a milky substance that is then scraped from the body of the toad. Robert Villa, who serves as president of the Tucson Herpetological Society, said in a 2022New York Times interview, "There’s a perception of abundance, but when you begin to remove large numbers of a species, their numbers are going to collapse like a house of cards at some point."[41]
Efforts to breed the toads in large quantities to offset their losses in the wild are criticized as potentially attracting predators to these areas, and creating a disease vector for pathogens such aschytrid fungus, which can then spread to devastate more of them in the wild. Synthetic forms of the drug that collectors seek in the toad poison are fairly easy to produce and may offset overcollection.[41]
^Gergus, Erik W. A.; Malmos, Keith B.; Sullivan, Brian K. (1999). "Natural hybridization among distantly related toads (Bufo alvarius,Bufo cognatus,Bufo woodhousii) in Central Arizona".Copeia.1999 (2):281–286.doi:10.2307/1447473.JSTOR1447473.
^Sullivan, Brian K.; Malmos, Keith B.; Movin, T. (1994). "Call variation in the Colorado River Toad (Bufo alvarius): behavioral and phylogenetic implications".Herpetologica.50 (2):146–156.doi:10.1007/BF00690963.JSTOR3893021.PMID3893021.S2CID22694946.
^Repke DB, Torres CM (2006).Anadenanthera: visionary plant of ancient South America. New York: Haworth Herbal Press.ISBN978-0-7890-2642-2.
^Weil, Andrew T.; Davis, Wade (January 1994). "Bufo alvarius: a potent hallucinogen of animal origin".Journal of Ethnopharmacology.41 (1–2):1–8.doi:10.1016/0378-8741(94)90051-5.PMID8170151.
^Krebs-Thomson, Kirsten; Ruiz, ErbertM.; Masten, Virginia; Buell, Mahalah; Geyer, MarkA. (December 2006). "The roles of 5-HT1A and 5-HT2 receptors in the effects of 5-MeO-DMT on locomotor activity and prepulse inhibition in rats".Psychopharmacology.189 (3):319–329.doi:10.1007/s00213-006-0566-1.PMID17013638.S2CID23396616.
^Lever, Christopher (2001).The Cane Toad: The History and Ecology of a Successful Colonist. Westbury Academic & Scientific Publishing.ISBN978-1-84103-006-7.
Frost, Darrel R.; Grant, Taran; Faivovich, JuliÁN; Bain, Raoul H.; Haas, Alexander; Haddad, CÉLIO F.B.; De SÁ, Rafael O.; Channing, Alan; Wilkinson, Mark; Donnellan, Stephen C.; Raxworthy, Christopher J.; Campbell, Jonathan A.; Blotto, Boris L.; Moler, Paul; Drewes, Robert C.; Nussbaum, Ronald A.; Lynch, John D.; Green, David M.; Wheeler, Ward C.; et al. (2006)."The Amphibian Tree of Life".Bulletin of the American Museum of Natural History.297:1–370.doi:10.1206/0003-0090(2006)297[0001:TATOL]2.0.CO;2.S2CID86140137.
_(8-6-13)_78_circulo_montana%2c_patagonia_lake_ranch_estates%2c_scc%2c_az_-01_(9466158294).jpg)
