Published October 15, 2020. Open access.

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Amazonian Toadhead (Bothrocophias hyoprora)

Reptiles of Ecuador | Serpentes | Viperidae | Bothrocophias hyoprora

English common names: Amazonian Toadhead, Amazonian Toad-headed Pitviper, Amazonian Hog-nosed Viper, Amazonian Hognose Viper.

Spanish common names: Nariz de puerco, hocico de puerco (Ecuador); sapa, equis sapa (Colombia); jergón pudridora, yatutu (Peru).

Recognition: ♂♂ 65.1 cmMaximum distance from the snout to the tip of the tail. ♀♀ 86 cmMaximum distance from the snout to the tip of the tail.. The Amazonian Toad-headed Pitviper (Botrocophias hyoprora) can be identified by having a triangular-shaped head, heat-sensing pits between the eyes and nostrils, a stout body, non-prehensile tail, upturned snout, and tubercular keels on the dorsal scales.1,2 The dorsal color may be reddish brown, dark brown, reddish orange, yellowish, or gray, with 14–19 dark trapezoidal or rectangular dorsal blotches.1,3 Bothrocophias hyoprora can be distinguished from the similar B. microphthalmus by having a pattern of trapezoidal blotches rather than X-shaped markings, and by having entire subcaudal scales.1,3 Bothrops atrox and B. brazili can be separated from B. hyoprora by lacking an upturned snout.3

Variation among individuals of Bothrocophias hyoprora

Figure 1: Individuals of Bothrocophias hyoprora from Gareno, Napo province, Ecuador (); Curaray medio, Pastaza province, Ecuador (); and Macuma, Morona Santiago province, Ecuador (). j=juvenile.

Natural history: UncommonUnlikely to be seen more than once every few months.. Bothrocophias hyoprora is a cryptozoic (preferring moist, shaded microhabitats) snake of forested environments. It occurs mainly in old-growth to moderately disturbed terra firme (not seasonally flooded) and partially flooded evergreen lowland forests but may as well be found in forest borders and human-modified areas such as crops.13 Amazonian Toad-headed Pitvipers inhabit areas having an annual mean temperature of ~20–27° C and a mean precipitation of 1659–4227 mm.4 Amazonian Toadheads are are most active during the first hours after sunset,1,2 waiting in ambush, moving on the forest floor, and occasionally crossing roads and trails.1,5 During the day, individuals often stay quiet, hidden from sun exposure in leaf-litter, under trunks, among roots, or at the base of trees.1,2,5 There are records of individuals perched on vegetation up to 5 m above the ground.6

Amazonian Toadheads are ambush predators. When prey is nearby, they “bite and release,” subsequently following the scent trail of the envenomed animal and finally proceed to eat it.1 Their diet consists primarily (41.5%) on lizards (including Alopoglossus atriventris and Potamites ecpleopus), but also on small mammals like rodents and marsupials (25%), frogs such as Allobates femoralis and Hyloxalus yasuni (25%), and centipedes (8.3%).1,7,811 They also occasionally include snakes in their diet.12

Individuals of Bothrocophias hyoprora rely on camouflage as their primary defense mechanism.1 They are not aggressive, but calm and sluggish when confronted.3 When threatened, most individuals will try to flee or hide, while others will vigorously vibrate the tail against the substrate.1,7 Little is known about the predators of Amazonian Toadhead Pitvipers. The only recorded predator is the Slate-colored Hawk (Buteogallus schistaceus).1

Bothrocophias hyoprora is a venomous snake, but human envenomations caused by this species are infrequent, representing no more than 0.35–12.5% of the total number of snakebites at any give locality.13,14 Most reported envenomations have occurred in indigenous communities.15 The venom of B. hyoprora is necrotic, hemolytic, and cytotoxic.1,13,16 In humans, the venom causes intense pain, swelling, loss of consciousness, necrosis (death of tissues and cells), intense bleeding, and, in some cases, death.1,15

What to do if you are bitten by a Amazonian Toadhead?

  1. Remain calm.
  2. Remove rings and tight fitting clothes to avoid swelling.
  3. Reduce movement of bitten extremity to reduce absorption of venom.
  4. Avoid the application of tourniquets, electric shocks, traditional medicine, venom suction, and incision of the bite wound.
  5. Plan immediate evacuation to a medical facility that has antivenom and avoid any action that may delay transportation.
  6. At the medical facility, personnel can initiate treatment with the appropriate antivenom, monitor vital signs, and perform laboratory tests.

Females of Bothrocophias hyoprora “give birth” (the eggs hatch within the mother) to 4–13 neonates that measure 14.8–19 cm in total length.1,2 One gravid female in Ecuador was found to contain 21 embryos.5 Under human care, one adult female lived for about eight years.1

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Conservation: Least Concern Believed to be safe from extinction given current circumstances.. Bothrocophias hyoprora has not been formally evaluated by the IUCN. In Ecuador, the species is listed as Least Concern17 because it is widely distributed throughout the Amazon basin, an area that retains the majority of its original forest cover. It is estimated that 88.5% of the species’ area of distribution in Ecuador still holds rainforest habitat.18 Bothrocophias hyoprora is also listed in this category because it occurs in large protected areas (such as Cuyabeno Wildlife Reserve and Yasuní National Park). The most important threat to the long-term survival of populations of this pitviper species is forest destruction due to mining and the expansion of the agricultural frontier.19

Distribution: Bothrocophias hyoprora is native to an estimated ~513,480 km2 area throughout the Amazon basin in Brazil, Bolivia, Colombia, Ecuador, and Peru.20 In Ecuador, the species occurs at elevations between 122 and 981 m (Fig. 2).

Distribution of Bothrocophias hyoprora in Ecuador

Figure 2: Distribution of Bothrocophias hyoprora in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Bothrocophias, which is derived from the Greek words bothros (meaning “pit”) and kophias (meaning “snake”), refers to the heat-sensing pits between the eyes and nostrils.3 The specific epithet hyoprora, which is derived from the Greek words hyos (meaning “hog”) and prora (meaning “snout”), refers to the prominent upturned snout.3

See it in the wild: Amazonian Toad-headed Pitvipers can be located with ~1–3% certainty in forested areas throughout the species distribution in Ecuador. Some of the best localities to find vipers of this species are Yasuní Scientific Station, Shiripuno Lodge, Jatun Sacha Biological Reserve, and Tiputini Biodiversity Station. These vipers are most easily located by scanning the leaf-litter along trails in primary forest at night.

Acknowledgments: Special thanks to Darwin Núñez, Ernesto Arbeláez, Jorge Vaca, and María Elena Barragán for providing locality data and natural history information for Bothrocophias hyoprora. Thanks to Ernesto Arbeláez (Bioparque Amaru) and María Elena Barragán (Vivarium Quito) for providing photographic access to live specimens under their care.

Special thanks to Maurice Fakkert for symbolically adopting the Amazonian Toadhead and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Authors: Andrés F. Aponte-Gutiérrez,aAffiliation: Grupo de Biodiversidad y Recursos Genéticos, Instituto de Genética, Universidad Nacional de Colombia, Bogotá, Colombia.,bAffiliation: Fundación Biodiversa Colombia, Bogotá, Colombia. Juan Acosta-Ortiz,cAffiliation: Universidad de los Llanos. Villavicencio, Colombia. and Leonardo Niño-CárdenasdAffiliation: Laboratorio de Anfibios, Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá, Colombia.

Editor: Alejandro ArteagaeAffiliation: Tropical Herping (TH), Quito, Ecuador.

Photographers: Jose VieiraeAffiliation: Tropical Herping (TH), Quito, Ecuador.,fAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagaeAffiliation: Tropical Herping (TH), Quito, Ecuador.

How to cite? Aponte-Gutiérrez A, Acosta-Ortiz J, Niño-Cárdenas L (2020) Amazonian Toadhead (Bothrocophias hyoprora). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/RICT3003

Literature cited:

  1. Valencia JH, Garzón-Tello K, Barragán-Paladines ME (2016) Serpientes venenosas del Ecuador: sistemática, taxonomía, historial natural, conservación, envenenamiento y aspectos antropológicos. Fundación Herpetológica Gustavo Orcés, Quito, 653 pp.
  2. Cisneros-Heredia DF, Borja MO, Proaño D, Touzet JM (2006) Distribution and natural history of the Ecuadorian toad-headed pitvipers of the genus Bothrocophias. Herpetozoa 19: 17–26.
  3. Campbell JA, Lamar WW (2004) The venomous reptiles of the western hemisphere. Cornell University Press, Ithaca, 774 pp.
  4. Vaca-Guerrero JE (2012) Biogeografía del género Bothrocophias (Serpentes: Viperidae: Crotalinae), mediante modelamientos de nicho ecológico. BSc Thesis, Universidad Central del Ecuador, 116 pp.
  5. Field notes, Reptiles of Ecuador book project.
  6. Photographic record by Bryan Suson.
  7. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  8. Martins M, Marques OAV, Sazima I (2002) Ecological and phylogenetic correlates of feeding habits in Neotropical pitvipers of the genus Bothrops. In: Schuett GW, Höggren M, Douglas ME, Greene HW (Eds) Biology of the vipers. Eagle Mountain Publishing, Eagle Mountain, 307–328.
  9. Niceforo M (1938) Las serpientes colombianas de hocico proboscidiforme, grupo Bothrops lansbergii-nasuta-hyoprora. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 2: 417–421.
  10. Santos JC, Cannatella DC (2011) Phenotypic integration emerges from aposematism and scale in poison frogs. Proceedings of the National Academy of Sciences of the United States of America 108: 6175-6180. DOI: 10.1073/pnas.1010952108
  11. Bernarde PS, Ferreira-Martins LS, Rodríguez-Oliveira J (2008) Bothrocophias hyoprora. Diet. Herpetological Review 39: 353.
  12. De Carvalho DT, de Fraga R, Eler ES, Kawashita-Ribeiro RA, Feldberg E, Vogt RC, De Carvalho MA, De Noronha JDC, Condrati LH, Bittencourt S (2013) Toad-headed pitviper Bothrocophias hyoprora (Amaral, 1935) (Serpentes, Viperidae): new records of geographic range in Brazil, hemipenial morphology, and chromosomal characterization. Herpetological Review 44: 410–414.
  13. Silva Haad J (1989) Las serpientes del genero Bothrops en la amazonia colombiana: aspectos biomedicos (epidemiologia, clinica y biologia del ofidismo). Acta Médica Colombiana 14: 148–165.
  14. Touzet JM (1986) Mordeduras de ofidios venenosos en la comunidad de los indígenas Siona-Secoya de San Pablo de Kantesyia y datos sobre la fauna de reptiles y anfibios locales. Publicaciones del Museo Ecuadoriano de Ciencias Naturales 7: 163–190.
  15. Warrell DA (2004) Snakebites in Central and South America: epidemiology, clinical features, and clinical management. In: Campbell JA, Lamar WW (Eds) The Venomous reptiles of the Western Hemisphere. Cornell University Press, Ithaca, 709–761.
  16. Bonilla C, Zavaleta A (1997) Estudio bioquímico del veneno de la serpiente Bothrops hyoprorus. Revista de Medicina Experimental 14: 18–32.
  17. Carrillo E, Aldás A, Altamirano M, Ayala F, Cisneros-Heredia DF, Endara A, Márquez C, Morales M, Nogales F, Salvador P, Torres ML, Valencia J, Villamarín F, Yánez-Muñoz M, Zárate P (2005) Lista roja de los reptiles del Ecuador. Fundación Novum Millenium, Quito, 46 pp.
  18. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  19. Valencia JH, Barragán ME, Garzón K, Vargas A (2010) Reporte preliminar de mordedura de vipéridos en la provincia de Manabí, y notas sobre las áreas epidemiológicas con mayor concentración de serpientes venenosas. Gestión Ambiental 2: 9–13.
  20. Nogueira CC, Argôlo AJS, Arzamendia V, Azevedo JA, Barbo FE, Bérnils RS, Bolochio BE, Borges-Martins M, Brasil-Godinho M, Braz H, Buononato MA, Cisneros-Heredia DF, Colli GR, Costa HC, Franco FL, Giraudo A, Gonzalez RC, Guedes T, Hoogmoed MS, Marques OAV, Montingelli GG, Passos P, Prudente ALC, Rivas GA, Sanchez PM, Serrano FC, Silva NJ, Strüssmann C, Vieira-Alencar JPS, Zaher H, Sawaya RJ, Martins M (2019) Atlas of Brazilian snakes: verified point-locality maps to mitigate the Wallacean shortfall in a megadiverse snake fauna. South American Journal of Herpetology 14: 1–274. DOI: 10.2994/SAJH-D-19-00120.1

Appendix 1: Locality data used to create the distribution map of Bothrocophias hyoprora in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

ColombiaCaquetáBocana CanelosVaca Guerrero 2012
ColombiaCaquetáLos ÁngelesSinchi Institute 2017
ColombiaCaquetáSolanoCampbell & Lamar 2004
ColombiaCaucaSanta RosaNogueira et al. 2019
ColombiaPutumayoE Puerto AsísiNaturalist
ColombiaPutumayoNear Río PatascoyiNaturalist
ColombiaPutumayoRío JuanambuCampbell & Lamar 2004
ColombiaPutumayoRN La Isla EscondidaRN La Isla Escondida
ColombiaPutumayoVereda Las VegasVaca Guerrero 2012
ColombiaPutumayoVereda PeneyaPhoto by Brayan Coral Jaramillo
EcuadorMorona Santiago10 de AgostoValencia et al. 2016
EcuadorMorona Santiago24 de MayoValencia et al. 2016
EcuadorMorona Santiago4 km NE of AndushCisneros-Heredia et al. 2006
EcuadorMorona SantiagoAmazonasCisneros-Heredia et al. 2006
EcuadorMorona SantiagoCentro Shuar KenkuimValencia et al. 2016
EcuadorMorona SantiagoCentro Shuar KiimCisneros-Heredia et al. 2006
EcuadorMorona SantiagoChuwintsCisneros-Heredia et al. 2006
EcuadorMorona SantiagoCusuimeNogueira et al. 2019
EcuadorMorona SantiagoE Puerto MoronaCampbell & Lamar 2004
EcuadorMorona SantiagoEl TiinkPhoto by Germán Petsain
EcuadorMorona SantiagoHuamboya, ChiguazaUSNM 165315
EcuadorMorona SantiagoMacumaValencia et al. 2016
EcuadorMorona SantiagoMutintzValencia et al. 2016
EcuadorMorona SantiagoPaantimValencia et al. 2016
EcuadorMorona SantiagoQuebrada YuwintsNogueira et al. 2019
EcuadorMorona SantiagoRío Palora at 800 mPhoto by Jorge Brito
EcuadorMorona SantiagoSan PedroValencia et al. 2016
EcuadorMorona SantiagoTaishaValencia et al. 2016
EcuadorMorona SantiagoTimiasValencia et al. 2016
EcuadorMorona SantiagoTiwintzaVaca Guerrero 2012
EcuadorMorona SantiagoTunantsValencia et al. 2016
EcuadorMorona SantiagoWisuiValencia et al. 2016
EcuadorMorona SantiagoYawintsValencia et al. 2016
EcuadorNapoGareno LodgeThis work
EcuadorNapoJatun SachaValencia et al. 2016
EcuadorNapoNear HuamaníValencia et al. 2016
EcuadorNapoPangayacuValencia et al. 2016
EcuadorNapoPuerto NapoUIMNH 55926
EcuadorNapoRío SunoValencia et al. 2016
EcuadorNapoS of Chontapunta 1iNaturalist
EcuadorNapoS of Chontapunta 2iNaturalist
EcuadorNapoYachana ReserveVaca Guerrero 2012
EcuadorNapoYuralpaValencia et al. 2016
EcuadorOrellanaChiruislaValencia et al. 2016
EcuadorOrellanaDicaroValencia et al. 2016
EcuadorOrellanaEl EdénValencia et al. 2016
EcuadorOrellanaGuiyeroValencia et al. 2016
EcuadorOrellanaJoya de los SachasCampbell & Lamar 2004
EcuadorOrellanaLoretoUSNM 165313
EcuadorOrellanaN of Yasuní Scientific StationiNaturalist
EcuadorOrellanaNenkepareThis work
EcuadorOrellanaNPFPaulina Romero, pers. comm.
EcuadorOrellanaNPF–Tivacuno, km 8 1/2Valencia et al. 2016
EcuadorOrellanaPompeya Sur–NPFValencia et al. 2016
EcuadorOrellanaPozo CapirónValencia et al. 2016
EcuadorOrellanaSan José de PayaminoPhoto by Ross Maynard
EcuadorOrellanaSE SumacoUSNM 165311
EcuadorOrellanaShiripuno LodgePhoto by Bryan Suson
EcuadorOrellanaSinchichictaValencia et al. 2016
EcuadorOrellanaSouther part of YNPCampbell & Lamar 2004
EcuadorOrellanaTiputini Biodiversity StationiNaturalist
EcuadorOrellanaVía Pompeya Sur-Iro, km 38Valencia et al. 2016
EcuadorOrellanaVía Pompeya Sur–Iro, km 28Cisneros-Heredia et al. 2006
EcuadorOrellanaVía Pompeya Sur–Iro, km 99Valencia et al. 2016
EcuadorOrellanaYasuní Scientific StationThis work
EcuadorPastazaAlto CurarayValencia et al. 2016
EcuadorPastazaBalsauraOrtega-Andrade 2010
EcuadorPastazaCabeceras del BobonazaValencia et al. 2016
EcuadorPastazaCampo OglánValencia et al. 2016
EcuadorPastazaCanelosUSNM 165306
EcuadorPastazaConamboUSNM 165302
EcuadorPastazaCuraray MedioThis work
EcuadorPastazaIwia (Achuar)Peñafiel 2013
EcuadorPastazaJuyuintzaOrtega-Andrade 2010
EcuadorPastazaKurintzaOrtega-Andrade 2010
EcuadorPastazaMontalvoValencia et al. 2016
EcuadorPastazaNorth of Kapawi LodgeCampbell & Lamar 2004
EcuadorPastazaPindoyacuOrtega-Andrade 2010
EcuadorPastazaRío CapahuariValencia et al. 2016
EcuadorPastazaRío CopatazaValencia et al. 2016
EcuadorPastazaRío CorrientesValencia et al. 2016
EcuadorPastazaRío OglánValencia et al. 2016
EcuadorPastazaRío PindoValencia et al. 2016
EcuadorPastazaRío ShionayacuValencia et al. 2016
EcuadorPastazaRío TigreUSNM 165318
EcuadorPastazaRío VillanoValencia et al. 2016
EcuadorPastazaSanta ClaraValencia et al. 2016
EcuadorPastazaSarayacuValencia et al. 2016
EcuadorPastazaSarayacu–MontalvoCampbell & Lamar 2004
EcuadorPastazaUpstream Río CopatazaCampbell & Lamar 2004
EcuadorPastazaUpstream Río TigreCampbell & Lamar 2004
EcuadorPastazaVillano AValencia et al. 2016
EcuadorSucumbíosAlong río San MiguelThis work
EcuadorSucumbíosAtenasVaca Guerrero 2012
EcuadorSucumbíosBetween Cascales and Campo BermejoVaca Guerrero 2012
EcuadorSucumbíosCampo Andes PetroleumVaca Guerrero 2012
EcuadorSucumbíosCampo BermejoValencia et al. 2016
EcuadorSucumbíosDureno, north ofValencia et al. 2016
EcuadorSucumbíosLumbaquiValencia et al. 2016
EcuadorSucumbíosPañacochaValencia et al. 2016
EcuadorSucumbíosPitsorie-SetsaccoValencia et al. 2016
EcuadorSucumbíosReserva Cofán-DurenoiNaturalist
EcuadorSucumbíosRío Aguarico near CuyabenoCampbell & Lamar 2004
EcuadorSucumbíosSacha LodgePhoto by Bryan Suson
EcuadorSucumbíosSan Pablo de KantesiyaValencia et al. 2016
EcuadorSucumbíosSanta ElenaQCAZ 2743
EcuadorSucumbíosSecoya 32Valencia et al. 2016
EcuadorSucumbíosShirley AValencia et al. 2016
EcuadorSucumbíosTarapoaValencia et al. 2016
EcuadorSucumbíosZábaloPhoto by Juan Carlos Ríos
EcuadorSucumbíosZancudocochaCisneros-Heredia et al. 2006
EcuadorZamora ChinchipeEl PanguiValencia et al. 2016
EcuadorZamora ChinchipeLos EncuentrosValencia et al. 2016
EcuadorZamora ChinchipeMaycuDarwin Núñez, pers. comm.
EcuadorZamora ChinchipeNamacuntzaNogueira et al. 2019
EcuadorZamora ChinchipePaquishaThis work
EcuadorZamora ChinchipePolvorínValencia et al. 2016
EcuadorZamora ChinchipeShaimeCisneros-Heredia et al. 2006
EcuadorZamora ChinchipeTundaymeValencia et al. 2016
PeruAmazonasCaterpizaMVZ 175374
PeruAmazonasPuerto PakuyLomonte et al. 2020
PeruAmazonasQuebrada KampankisFMNH 2012
PeruLoretoAguas NegrasFMNH 2008
PeruLoretoCharupaVaca Guerrero 2012
PeruLoretoGüeppíFMNH 2008
PeruLoretoLote 39Tomba 2019
PeruLoretoMansericheCampbell & Lamar 2004
PeruLoretoMoronaVaca Guerrero 2012
PeruLoretoNW of PavayacuVaca Guerrero 2012
PeruLoretoOlaya–TigreCampbell & Lamar 2004
PeruLoretoPampa HermosaCampbell & Lamar 2004
PeruLoretoPongo ChinimFMNH 2012
PeruLoretoPozo al este de AndoasVaca Guerrero 2012
PeruLoretoPozo al norte de AndoasVaca Guerrero 2012
PeruLoretoPozo al sur del Río TigreVaca Guerrero 2012
PeruLoretoS AricaCampbell & Lamar 2004
PeruLoretoW AndoasCampbell & Lamar 2004
PeruLoretoZona Reservada GüepiiNaturalist
PeruLoretoZona Reservada Pucacuro 1Campbell & Lamar 2004
PeruLoretoZona Reservada Pucacuro 2Campbell & Lamar 2004