Published February 14, 2024. Open access.

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Western Rainbow Boa (Epicrates cenchria)

Reptiles of Ecuador | Serpentes | Boidae | Epicrates cenchria

English common names: Western Rainbow Boa, Brazilian Rainbow Boa.

Spanish common name: Boa arcoiris, boa tornasol.

Recognition: ♂♂ 185.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=165 cm. ♀♀ 192 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=170.5 cm..1 Epicrates cenchria is considered to be the most beautiful snake in the world.2 It can easily be identified from other boas based on its distinctive orange attire with a bluish iridescence. The back is bright orange-red with a series of sinuous black rings. The lower flanks are pale gray with ocelli consisting of a black ellipsis enclosing an orange-yellow crescent (Fig. 1).3 This species further differs from other boas by having three longitudinal dark stripes on top of the head as well as heat-sensing pits in the lower and anterior upper labials.1,4 Unlike the tree-boas (genus Corallus), E. cenchria has a rounded, instead of laterally compressed, body.1

Figure showing variation among individuals of Epicrates cenchria

Figure 1: Individuals of Epicrates cenchria from Ecuador: Aguas Negras Lodge, Sucumbíos province (); Napo Wildlife Center, Orellana province (); Curaray medio, Pastaza province (); unknown locality, Morona Santiago province (). j=juvenile.

Natural history: Epicrates cenchria is a primarily terrestrial boid, with juveniles being more arboreal than adults.1,4,5 The species occurs in pristine rainforests, but also ventures into disturbed habitats such as pastures, rural gardens, and man-made structures near the forest.47 Rainbow Boas exhibit both diurnal and nocturnal habits and forage primarily on the rainforest floor, but may also utilize shrubs, branches, and logs up to 9 m above the ground.35 Active individuals have been seen crossing trails, roads, and streams as well as coiled in ambush posture on shrubs.4,5 Semi-aquatic activity has also been reported, with individuals being found submerged in forest pools4 or swimming in streams.5 When not active, they seek shelter in ground burrows,3 tree holes, inside rotten logs, or in leaf-litter.4,8 They utilize both active foraging and ambush strategies to capture prey. Seized prey is wrapped by body coils and constricted until suffocation. Prey items include primarily mammals such as rodents,4,8,9 porcupines,10 and bats,4,11,12 but also birds13 and their eggs,4,14 lizards, and amphibians.15 Bats are ambushed on trees, at the entrance of caves, or in abandoned houses.4,5,11,12 Domestic animals such as chickens are also frequently consumed.4,16 When threatened, individuals usually make an S-coil and strike.4 They can also adopt a “protective ball posture.”5 There are recoded instances of predation on members of this species by canids (Short-eared Dog17 and Crab-eating Fox18) and raptors.19 The breeding season in E. cenchria occurs from late March to late September, and births occur from from December to March.20 During courtship, the males use the pelvic spurs, which are usually larger than those of females’.21 After a gestation period of 5–8 months,21,22 females “give birth” (the eggs hatch within the mother) to 4–25 young.2124 This species is capable of facultative parthenogenesis, meaning embryos can develop from unfertilized eggs.23 In captivity, individuals can live up to 22 years.23

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..25 Epicrates cenchria is listed in this category because the species has large, stable populations and a wide distribution that includes numerous protected areas.25 Ongoing threats include traffic mortality26 and poaching for the international trade of exotic wildlife.

Distribution: Epicrates cenchria is widely distributed throughout the Amazon rainforest in Bolivia, Brazil, Colombia, Ecuador (Fig. 2), French Guiana, Guyana, Peru, Suriname, and Venezuela. The species also occurs in the Atlantic Forest of Brazil.27

Distribution of Epicrates cenchria in Ecuador

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

Etymology: The generic name Epicrates comes from the Greek word epikrates (=strong one).28 The specific epithet cenchria comes from the Greek word kenchris (a kind of hawk),28 and probably refers to the face pattern.

See it in the wild: Western Rainbow Boas are seen at a rate of about once every few weeks throughout their area of distribution in Ecuador. Prime localities for this species include Limoncocha Biological Reserve, Yasuní Scientific Station, and Jatun Sacha Biological Reserve.

Special thanks to Amanda Hartley for symbolically adopting the Western Rainbow Boa and helping bring the Reptiles of Ecuador book project to life.

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Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2024) Western Rainbow Boa (Epicrates cenchria). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/MPYQ4819

Literature cited:

  1. Duellman WE (1978) The biology of an equatorial herpetofauna in Amazonian Ecuador. Publications of the Museum of Natural History, University of Kansas 65: 1–352.
  2. Murphy JB (2014) Studies on pythons, boas and anacondas, dwarf boas, and Round Island splitjaw snakes in zoos and aquariums. Herpetological Review 45: 535–556.
  3. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  4. Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
  5. Field notes, Reptiles of Ecuador book project.
  6. Camper JD, Torres-Carvajal O, Ron SR, Nilsson J, Arteaga A, Knowles TW, Arbogast BS (2021) Amphibians and reptiles of Wildsumaco Wildlife Sanctuary, Napo Province, Ecuador. Check List 17: 729–751.
  7. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  8. Medeiros de Pinho G, Oliveira de Lima D, Nogueira da Costa P, Dos Santos Fernandez FA (2009) Epicrates cenchria (Brazilian Rainbow Boa): diet. Herpetological Review 40: 354–355.
  9. Bernarde PS, Abe AS (2010) Food habits of snakes from Espigão do Oeste, Rondônia, Brazil. Biota Neotropica 10: 167–173.
  10. Photo by Nancy Overholtz.
  11. Ramos Donato C, Trindade Dantas MA, da Rocha PA (2012) Epicrates cenchria (Rainbow Boa): diet and foraging behavior. Herpetological Review 43: 343–344.
  12. Martin-Solano S, Toulkeridis T, Addison A, Pozo-Rivera WE (2016) Predation of Desmodus rotundus Geoffroy, 1810 (Phyllostomidae, Chiroptera) by Epicrates cenchria (Linnaeus, 1758) (Boidae, Reptilia) in an Ecuadorian Cave. Subterranean Biology 19: 41–50. DOI: 10.3897/subtbiol.19.8731
  13. Beebe W (1946) Field notes on the snakes of Kartabo, British Guiana, and Caripito, Venezuela. Zoologica 31: 11–52.
  14. Ferreto Fiorillo B (2019) Predation on eggs of the Gray Tinamou (Tinamus tao, Tinamiformes: Tinamidae) by the rainbow boa (Epicrates cenchria, Serpentes: Boidae). Herpetology Notes 12: 79–81.
  15. Henderson RW (1993) On the diets of some arboreal boids. Herpetological Natural History 1: 91–96.
  16. Mansur Martinelli I (2011) Epicrates cenchria (Rainbow Boa): diet. Herpetological Review 42: 289–290.
  17. Photo by Diego Mosquera.
  18. Carvalho F, Ceron K, Bôlla DAS, Santos R, Miranda JMD, Zocche JJ (2017) Epicrates cenchria (Rainbow Boa): predation. Herpetological Review 48: 212.
  19. Ramírez-Jaramillo SM, Ramírez-Jaramillo JM (2020) Registros de ataque y depredación sobre anfibios y reptiles de Limoncocha, Amazonía norte de Ecuador. Acta Zoológica Lilloana 64: 65–72.
  20. Garcia VC, de Almeida-Santos SM (2022) Reproductive cycles of neotropical boid snakes evaluated by ultrasound. Zoo Biology 41: 74–83. DOI: 10.1002/zoo.21646
  21. van der Pols JJ (1987) Unexpected breeding of Epicrates cenchria cenchria. Litteratura Serpentium 7: 168–174.
  22. Hine RA (1988) Captive breeding of the Brazilian Rainbow Boa Epicrates cenchria cenchria. British Herpetological Society Bulletin 23: 25–29.
  23. Kinney ME, Wack RF, Grahn RA, Lyons L (2012) Parthenogenesis in a Brazilian Rainbow Boa (Epicrates cenchria cenchria). Zoo Biology 32: 172–176. DOI: 10.1002/zoo.21050
  24. de Fraga R, Lima AP, da Costa Prudente AL, Magnusson WE (2013) Guia de cobras da região de Manaus - Amazônia Central. Editopa Inpa, Manaus, 303 pp.
  25. Calderón M, Ortega A, Catenazzi A, Gagliardi G, Cisneros-Heredia DF, Nogueira CC, Schargel W, Rivas G (2020) Epicrates cenchria. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2021-2.RLTS.T15154721A15154747.en
  26. Medrano-Vizcaíno P, Brito-Zapata D, Rueda-Vera A, Jarrín-V P, García-Carrasco JM, Medina D, Aguilar J, Acosta-Buenaño N, González-Suárez M (2023) First national assessment of wildlife mortality in Ecuador: an effort from citizens and academia to collect roadkill data at country scale. Ecology and Evolution 13: e9916. DOI: 10.1002/ece3.9916
  27. 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
  28. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.

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

ColombiaCaquetáCampamento Bajo Aguas NegrasValderrama 2023
ColombiaCaquetáCasacunteiNaturalist; photo examined
ColombiaCaquetáFlorenciaNogueira et al. 2019
ColombiaCaquetáLas VerdesGutiérrez-Lamus et al. 2020
ColombiaCaquetáLos ÁngelesGutiérrez-Lamus et al. 2020
ColombiaCaquetáPuerto RicoiNaturalist; photo examined
ColombiaCaquetáReserva Doña BlancaiNaturalist; photo examined
ColombiaCaquetáTres EsquinasNogueira et al. 2019
ColombiaPutumayoBajo MansoyáCahueño & Barbosa 2022
ColombiaPutumayoNariñoGeopark Colombia & SGS Colombia 2022
ColombiaPutumayoPozo PiñuñaiNaturalist; photo examined
ColombiaPutumayoReserva La Isla EscondidaiNaturalist; photo examined
ColombiaPutumayoRío PutumayoAMNH 114716; VertNet
ColombiaPutumayoSinaí II BaldíoCahueño & Barbosa 2022
ColombiaPutumayoVereda 35iNaturalist; photo examined
ColombiaPutumayoVereda La UnióniNaturalist; photo examined
ColombiaPutumayoVereda San CarlosiNaturalist; photo examined
EcuadorMorona SantiagoArapicosNogueira et al. 2019
EcuadorMorona SantiagoEl TiinkReptiles of Ecuador book database
EcuadorMorona SantiagoGualaquizaKU 147193; VertNet
EcuadorMorona SantiagoMacasUSNM 65485; VertNet
EcuadorMorona SantiagoMacumaNogueira et al. 2019
EcuadorMorona SantiagoPaloraNogueira et al. 2019
EcuadorMorona SantiagoPiamonteiNaturalist; photo examined
EcuadorMorona SantiagoPuerto Morona, 4 km W ofCarvajal-Campos et al. 2022
EcuadorMorona SantiagoRío LlushinUSNM 204096; VertNet
EcuadorMorona SantiagoRío YasuníCarvajal-Campos et al. 2022
EcuadorMorona SantiagoSantiago de MendezUSNM 204097; VertNet
EcuadorMorona SantiagoShuin MamusiNaturalist; photo examined
EcuadorMorona SantiagoSucúaMCZ 145353; VertNet
EcuadorMorona SantiagoTurulaAMNH 23278; examined
EcuadorMorona SantiagoWisuiChaparro et al. 2011
EcuadorNapoArchidonaNogueira et al. 2019
EcuadorNapoCotundoNogueira et al. 2019
EcuadorNapoEl ChacoPhoto by Diego Piñán
EcuadorNapoHidroeléctrica Coca Codo SinclairCOCASINCLAIR 2013
EcuadorNapoHuaorani LodgeReptiles of Ecuador book database
EcuadorNapoJatun Sacha Biological ReserveReptiles of Ecuador book database
EcuadorNapoNarupa ReserveReptiles of Ecuador book database
EcuadorNapoPozo Yuralpa Centro 1Nogueira et al. 2019
EcuadorNapoReserva Río BigaiReptiles of Ecuador book database
EcuadorNapoTenaNogueira et al. 2019
EcuadorNapoWild Sumaco Lodge, 4 km S ofCamper et al. 2021
EcuadorNapoYachana ReserveWhitworth & Beirne 2011
EcuadorOrellanaÁvila ViejoNogueira et al. 2019
EcuadorOrellanaBloque 31Libro PetroAmazonas
EcuadorOrellanaEl CocaMHNG 2220.1; collection database
EcuadorOrellanaHacienda PrimaveraMHNG 2412.073; collection database
EcuadorOrellanaLa Joya de los SachasNogueira et al. 2019
EcuadorOrellanaMandaripanga LodgeReptiles of Ecuador book database
EcuadorOrellanaPompeya, 4 km S ofNogueira et al. 2019
EcuadorOrellanaPozo Ishpingo BiNaturalist; photo examined
EcuadorOrellanaRío Bigal ReserveGarcía et al. 2021
EcuadorOrellanaRío CocaNogueira et al. 2019
EcuadorOrellanaSan José de PayaminoMaynard et al. 2016
EcuadorOrellanaShiripuno LodgePhoto by Jarold Vaca
EcuadorOrellanaTiputini Biodiversity Station Cisneros-Heredia 2003
EcuadorOrellanaVía Maxus, km 97Nogueira et al. 2019
EcuadorOrellanaYasuní Scientific StationReptiles of Ecuador book database
EcuadorPastazaArajuno Nogueira et al. 2019
EcuadorPastazaBalsauraOrtega-Andrade 2010
EcuadorPastazaCamino al PuyoNogueira et al. 2019
EcuadorPastazaCampamento K26Nogueira et al. 2019
EcuadorPastazaCanelosAMNH 35895; examined
EcuadorPastazaConamboOrtega-Andrade 2010
EcuadorPastazaCuraray MedioThis work; Fig. 1
EcuadorPastazaEstación Agro-Ecológica FátimaProaño-Morales et al. 2017
EcuadorPastazaJuyuintzaOrtega-Andrade 2010
EcuadorPastazaKapawi LodgeReptiles of Ecuador book database
EcuadorPastazaMacas–PuyoReptiles of Ecuador book database
EcuadorPastazaMeraNogueira et al. 2019
EcuadorPastazaPaltaNogueira et al. 2019
EcuadorPastazaPaparawuaNogueira et al. 2019
EcuadorPastazaPuyoReptiles of Ecuador book database
EcuadorPastazaShellNogueira et al. 2019
EcuadorPastazaSumak Kawsay In SituBentley et al. 2021
EcuadorPastazaVillanoNogueira et al. 2019
EcuadorSucumbíosAguas Negras LodgeThis work; Fig. 1
EcuadorSucumbíosCuyabeno LodgeReptiles of Ecuador book database
EcuadorSucumbíosEl Eno, 500 m N ofNogueira et al. 2019
EcuadorSucumbíosEstación de Bombeo 3Photo by Diego Piñán
EcuadorSucumbíosEstación de la Católica en CuyabenoReptiles of Ecuador book database
EcuadorSucumbíosGarita Casa de MáquinasNogueira et al. 2019
EcuadorSucumbíosGüeppicilloYánez-Muñoz & Venegas 2008
EcuadorSucumbíosJambelíNogueira et al. 2019
EcuadorSucumbíosLa Selva LodgeReptiles of Ecuador book database
EcuadorSucumbíosLago AgrioDuellman 1978
EcuadorSucumbíosLaguna GrandeReptiles of Ecuador book database
EcuadorSucumbíosLas PizarrasiNaturalist; photo examined
EcuadorSucumbíosLimoncocha Biological ReserveNogueira et al. 2019
EcuadorSucumbíosLumbaquiNogueira et al. 2019
EcuadorSucumbíosNapo Wildlife CenterThis work; Fig. 1
EcuadorSucumbíosRemolinoiNaturalist; photo examined
EcuadorSucumbíosRío GüeppiYanez-Muñoz et al. 2017
EcuadorSucumbíosSani LodgeReptiles of Ecuador book database
EcuadorSucumbíosSanta Cecilia Duellman 1978
EcuadorSucumbíosTarapoaNogueira et al. 2019
EcuadorSucumbíosTucan LodgePhoto by Harry Turner
EcuadorSucumbíosVía a Campo AlegreiNaturalist; photo examined
EcuadorZamora ChinchipeCopalingaReeves et al.
EcuadorZamora ChinchipeEl PadmiGonzález et al. 2010
EcuadorZamora ChinchipeTunantzaPhoto by Darwin Núñez
EcuadorZamora ChinchipeValle del QuimiBetancourt et al. 2018
EcuadorZamora ChinchipeVía a Nuevo ParaísoiNaturalist; photo examined
EcuadorZamora ChinchipeYantzazaCuerpo bomberos Yantzaza
PeruAmazonasAguaruna VillageMVZ 163377; VertNet
PeruAmazonasAramango, 5 km NE ofLSUMZ 19602; VertNet
PeruAmazonasCaterpizaUSNM 566709; VertNet
PeruAmazonasKusuMVZ 163378; VertNet
PeruAmazonasLa PozaMVZ 175301; VertNet
PeruAmazonasPaagatUSNM 316567; VertNet
PeruAmazonasUpper Río ComainasUSNM 525554; VertNet
PeruAmazonasYutupisUSNM 566539; VertNet
PeruLoretoAguas NegrasYánez-Muñoz & Venegas 2008
PeruLoretoCerro de KampankisCatenazzi & Venegas 2016
PeruLoretoMoroponTCWC 42066; VertNet
PeruLoretoRedondocochaYánez-Muñoz & Venegas 2008
PeruLoretoSanta MaríaTCWC 42064; VertNet