Published May 9, 2021. Updated March 7, 2024. Open access.

Gallery ❯

Brown Whipsnake (Chironius fuscus)

Reptiles of Ecuador | Serpentes | Colubridae | Chironius fuscus

English common names: Brown Whipsnake, Brown Sipo, Olive Whipsnake, Red-fronted Tree Snake.

Spanish common name: Serpiente látigo marrón, serpiente látigo oliva (Ecuador); cazadora, juetiadora, lomo de machete (Colombia); serpiente de olivo, sipo marrón (Peru); cuaima machete, cuaima gallo, machete, verdegallo (Venezuela).

Recognition: ♂♂ 159.7 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=109.5 cm. ♀♀ 151.4 cmMaximum distance from the snout to the tip of the tail..1,2 Chironius fuscus can be identified by having 10 rows of dorsal scales at mid-body, keels on either side of the vertebral line, and a olivaceous or brownish dorsal coloration (Fig. 1).14 The keels may be darkened, giving the appearance of two dark stripes.1 The venter is cream or yellowish, becoming darker towards the tail.1,4 Juveniles are olive to brown with light transverse bands, which tend to disappear when the animal reaches a body length of 35–40 cm.1,3 This species differs from C. exoletus and C. multiventris by having 10 rows of dorsal scales at mid-body.1 From the adults of C. scurrula, it differs by having a brown, instead of red or black dorsum.1,5 From C. leucometapus, it differs by having a brown, instead of green, dorsum and by having a postocular stripe.6

Figure showing variation among individuals of Chironius fuscus

Figure 1: Individuals of Chironius fuscus from Ecuador: Yasuní Scientific Station, Orellana province (); Huella Verde Lodge, Pastaza province (); Nangaritza, Zamora Chinchipe province (). j=juvenile.

Natural history: Chironius fuscus is a common diurnal and semi-arboreal snake that inhabits old-growth to heavily disturbed evergreen forests, which can be terra-firme or seasonally flooded.3,5,7 The species also occurs in human-modified environments such as grasslands and plantations.8,9 Brown Whipsnakes are almost exclusively active during warm days, but there are records of individuals foraging at night near ponds.10 Most of their active time is spent foraging at ground level or moving on vegetation 0.4–2 m above the ground.2,10,11 They can also be seen crossing roads and trails, resting/basking on trees or at ground level, and swimming across bodies of water, including major Amazonian rivers.5,9,12 Around 6:00–7:00 pm, these snakes begin to look for a perch to sleep,13 such as branches, leaves, and ferns near bodies of water at 0.2–5 m above the ground.3,9,11 An individual can use the same roosting place repeatedly.10 If disturbed during their sleep, Brown Whipsnakes will usually drop to the ground, quickly ascending to the nearest vegetation.3

Brown Whipsnakes are active hunters having an aglyphous dentition, meaning their teeth lack specialized grooves to deliver venom.1,2 Therefore, they ingest prey quickly to avoid them from escaping.1,2 Their diet consists mainly of anurans (including Boana boans,14 Leptodactylus petersii, L. mystaceus, Osteocephalus taurinus,9 and Trachycephalus macrotis),15 but also includes salamanders,15 lizards (anoles,16 whiptails,17 and geckos such as Gonatodes humeralis),15 birds, and mice.16 There are records of Laughing Falcons (Herpetotheres cachinnans) preying upon individuals of this species.12 The main defense mechanism of Brown Whipsnakes is to flee quickly, although they can also inflate the neck and open the mouth aggressively to appear bigger and intimidating; if this does not work, they can also strike.5,16 Males attain sexual maturity when they reach ~53 cm in total length; females at ~57.6 cm.18 The breeding season in this species seems be continuous, since females having oviductal eggs (between 3 and 8) have been recorded throughout the year.17,18

Reader support helps us keep the Reptiles of Ecuador book 100% free.

Conservation: Least Concern Believed to be safe from extinction given current circumstances..1921 Chironius fuscus is included in this category given the species’ wide distribution, occurrence in protected areas (including all major national parks in Amazonian Ecuador), and presumed stable populations.19 However, the abundance of this species is thought to be diminishing in areas affected by deforestation19 and vehicular traffic.22,23

Distribution: Chironius fuscus is widely distributed throughout the Amazon in Bolivia, Brazil, Colombia, Ecuador (Fig. 2), French Guiana, Guyana, Peru, Suriname and Venezuela, as well as in the Atlantic Forest biome of Brazil. The species has an estimated total range size of 2,139,501 km2.24

Distribution of Chironius fuscus in Ecuador

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

Etymology: The name Chironius was coined by Leopold Fitzinger in 1826, but likely originated in 1790 with Blasius Merrem, who used the common name “Chiron’s Natter” for Linnaeus’ Coluber carinatus.25 In Greek mythology, Chiron was a centaur reputed for his healing abilities. Likewise, in ancient Greek civilization, sick people hoping for a cure flocked to temples where sacred snakes were carefully tended and presented to the sufferers. Therefore, Chironius likely refers to the healing power of snakes, a belief that lies at the foundation of medicine and crosses many cultures worldwide.26,27 The specific epithet fuscus is a Latin word meaning “dark” or “swarthy.”28 It refers to the dark coloration of the body and the postocular dark stripe present in some individuals.

See it in the wild: Brown Whipsnakes are frequently encountered in forested areas throughout their area of distribution in Ecuador. The localities having the greatest number of observations are Yasuní Scientific Station, Maycu Reserve, and Tamandúa Reserve. The snakes are most easily spotted when they are sleeping on vegetation along water bodies at night, or moving on pastures during sunny days.

Special thanks to Mami Okura for symbolically adopting the Brown Whipsnake and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Authors: Juan Acosta-Ortiz,aAffiliation: Semillero de Investigación BioHerp, Universidad de los Llanos, Villavicencio, Colombia. Juan Bobadilla-Molina,aAffiliation: Semillero de Investigación BioHerp, Universidad de los Llanos, Villavicencio, Colombia. and Andrés F. Aponte-GutiérrezbAffiliation: Grupo de Biodiversidad y Recursos Genéticos, Instituto de Genética, Universidad Nacional de Colombia, Bogotá, Colombia.,cAffiliation: Fundación Biodiversa Colombia, Bogotá, Colombia.

Editor: Alejandro ArteagadAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose VieiradAffiliation: Tropical Herping (TH), Quito, Ecuador.eAffiliation: ExSitu, Quito, Ecuador.

How to cite? Acosta-Ortiz J, Bobadilla-Molina J, Aponte-Gutiérrez A (2024) Brown Whipsnake (Chironius fuscus). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/RZHK7496

Literature cited:

  1. Dixon JR, Wiest Jr JA, Cei JM (1993) Revision of the Neotropical snake genus Chironius Fitzinger (Serpentes, Colubridae). Museo Regionale di Scienze Naturali di Torino, Torino, 280 pp.
  2. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  3. 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.
  4. 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.
  5. Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
  6. Torres-Carvajal O, Koch C, Valencia JH, Venegas PJ, Echevarría LY (2019) Morphology and distribution of the South American snake Chironius leucometapus (Serpentes: Colubridae). Phyllomedusa 18: 241–254. DOI: 10.11606/issn.2316-9079.v18i2p241-254
  7. Cunha OR, Nascimento FP (1993) Ofídios da Amazônia. As cobras da região leste do Pará. Papéis Avulsos Museu Paraense Emílio Goeldi 40: 9–87.
  8. Cortes-Ávila L, Toledo JJ (2013) Estudio de la diversidad de serpientes en áreas de bosque perturbado y pastizal en San Vicente del Caguán (Caquetá), Colombia. Actualidades Biológicas 35: 185–197.
  9. Field notes, Reptiles of Ecuador book project.
  10. Hartmann PA (2005) História natural e ecologia de duas taxocenoses de serpentes na Mata Atlântica. PhD thesis, Rio Claro, Universidade Estadual Paulista, 117 pp.
  11. Field notes of Juan Sebastián Bobadilla-Molina.
  12. Field notes of Andrés Felipe Aponte-Gutiérrez.
  13. Field notes of Juan Manuel Acosta-Ortiz.
  14. Arrivillaga C, Levac A (2019) A failed predation attempt on a Rusty Treefrog, Hypsiboas boans (Anura: Hylidae), by an Olive Whipsnake, Chironius fuscus (Squamata: Colubridae), in southeastern Perú. IRCF Reptiles & Amphibians 26: 111–112.
  15. Roberto IJ, Ramos Souza A (2020) Review of prey items recorded for snakes of the genus Chironius (Squamata, Colubridae), including the first record of Osteocephalus as prey. Herpetology Notes 13: 1–5.
  16. Beebe W (1946) Field notes on the snakes of Kartabo, British Guiana, and Caripito, Venezuela. Zoologica 31: 11–52.
  17. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  18. Nascimento LP, Mendes Siqueira D, dos Santos-Costa MC (2013) Diet, reproduction, and sexual dimorphism in the Vine Snake, Chironius fuscus (Serpentes: Colubridae), from Brazilian Amazonia. South American Journal of Herpetology 8: 168–174. DOI: 10.2994/SAJH-D-13-00017.1
  19. Caicedo J, Gutiérrez-Cárdenas P, Rivas G, Nogueira C, Gonzales L, Cisneros-Heredia DF, Catenazzi A, Gagliardi G, Hoogmoed M, Schargel W (2019) Chironius fuscus. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2019-3.RLTS.T44580103A44580112.en
  20. 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.
  21. Reyes-Puig C (2015) Un método integrativo para evaluar el estado de conservación de las especies y su aplicación a los reptiles del Ecuador. MSc thesis, Pontificia Universidad Católica del Ecuador, 73 pp.
  22. Hartmann PA, Hartmann MT, Martins M (2011) Snake road mortality in a protected area in the Atlantic Forest of southeastern Brazil. South American Journal of Herpetology 36: 35–42.
  23. Sosa R, Schalk CM (2016) Seasonal activity and species habitat guilds influence road-kill patterns of neotropical snakes. Tropical Conservation Science 9: 1–12. DOI: 10.1177/1940082916679662
  24. 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
  25. Merrem B (1790) Beitrage zur Naturgeschichte. Duisburg um Lemgo, Berlin, 141 pp.
  26. Nayernouri T (2010) Asclepius, caduceus, and simurgh as medical symbols. Archives of Iranian Medicine 13: 61–68.
  27. Güner E, Şeker KG, Güner Ş (2019) Why is the medical symbol a snake? Istanbul Medical Journal 20: 172–175. DOI: 10.4274/imj.galenos.2018.65902
  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 Chironius fuscus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

ColombiaCaquetáCaserío Los ÁngelesCaicedo Portilla 2023
ColombiaCaquetáFinca de Erley NavasCaicedo Portilla 2023
ColombiaCaquetáLas Dalias Nature and Ecotourism ReservePhoto by John Himes
ColombiaCaquetáQuebrada Las VerdesCaicedo Portilla 2023
ColombiaPutumayoFinca MariposaCalderón et al. 2023
ColombiaPutumayoMocoaCárdenas Hincapié & Lozano Bernal 2023
ColombiaPutumayoReserva AmaruiNaturalist; photo examined
ColombiaPutumayoRío GuamuésiNaturalist; photo examined
EcuadorLoretoSan José de PayaminoiNaturalist; photo examined
EcuadorMorona SantiagoComunidad KiimOnline multimedia
EcuadorMorona SantiagoComunidad Shuar KunkukTorres-Carvajal et al. 2019
EcuadorMorona SantiagoCusuimeOrtega-Andrade 2010
EcuadorMorona SantiagoEl PescadoNogueira et al. 2019
EcuadorMorona SantiagoGualaquizaDixon et al. 1993
EcuadorMorona SantiagoKushapucusMZUA.RE.0196; examined
EcuadorMorona SantiagoMacasDixon et al. 1993
EcuadorMorona SantiagoMacumaDixon et al. 1993
EcuadorMorona SantiagoMirador de la VirgenTorres-Carvajal et al. 2019
EcuadorMorona SantiagoNuevo IsraelTorres-Carvajal et al. 2019
EcuadorMorona SantiagoQuebrada NamakuntsTorres-Carvajal et al. 2019
EcuadorMorona SantiagoRio CusuimeNogueira et al. 2019
EcuadorMorona SantiagoRío Napinaza Nogueira et al. 2019
EcuadorMorona SantiagoSan Juan BoscoMZUA.RE.0241; examined
EcuadorMorona SantiagoSanta TeresaUSNM 283946; VertNet
EcuadorMorona SantiagoSucúaFugler & Walls 1978
EcuadorMorona SantiagoTundaymeReptiles of Ecuador book database
EcuadorMorona SantiagoWisuiChaparro et al. 2011
EcuadorNapoAhuanoMCZ 173828; VertNet
EcuadorNapoCarlos Julio Arosemena TolaNogueira et al. 2019
EcuadorNapoCotundo, 12 km NW ofNogueira et al. 2019
EcuadorNapoGareno LodgePhoto by Sandro Aguinda
EcuadorNapoJatun Sacha Biological StationMCZ 173828; VertNet
EcuadorNapoNarupa ReserveReptiles of Ecuador book database
EcuadorNapoPitalala, mesetaReptiles of Ecuador book database
EcuadorNapoRío MisahuallíDixon et al. 1993
EcuadorNapoRío Napo, YasunÍ National Park iNaturalist; photo examined
EcuadorNapoSan FranciscoFugler & Walls 1978
EcuadorNapoSan Juan de MuyunaiNaturalist; photo examined
EcuadorNapoSan Juan de PiatuaReptiles of Ecuador book database
EcuadorNapoTenaDixon et al. 1993
EcuadorNapoVía Guamaní–HollínNogueira et al. 2019
EcuadorNapoWild Sumaco, lower trailsPhoto by Dr. Dark
EcuadorNapoYachana ReserveWhitworth & Beirne 2011
EcuadorNapoZoo el ArcaPhoto by Diego Piñán
EcuadorOrellanaÁvila ViejoTorres-Carvajal et al. 2019
EcuadorOrellanaCocaOnline multimedia
EcuadorOrellanaComunidad Chiru IslaPaulina Romero, pers. comm.
EcuadorOrellanaComunidad SinchichiktaTorres-Carvajal et al. 2019
EcuadorOrellanaCotapinoFugler & Walls 1978
EcuadorOrellanaLaguna JatuncochaReptiles of Ecuador book database
EcuadorOrellanaLaguna ZancudoNogueira et al. 2019
EcuadorOrellanaLoretoUSNM 287927; VertNet
EcuadorOrellanaPozo ChontaNogueira et al. 2019
EcuadorOrellanaPozo Petrolero NambiNogueira et al. 2019
EcuadorOrellanaRío Bigal Biological ReserveGarcía et al. 2021
EcuadorOrellanaRío YasuníMaría Jose Quiroz, pers. comm.
EcuadorOrellanaSan José de PayaminoMaynard et al. 2017
EcuadorOrellanaTambocochaTorres-Carvajal et al. 2019
EcuadorOrellanaTiputini Biodiversity Station Cisneros-Heredia 2003
EcuadorOrellanaVía Loreto-Río HollínTorres-Carvajal et al. 2019
EcuadorOrellanaVía Pompeya Sur–Iro, km 40Photo by Morley Read
EcuadorOrellanaVía Pompeya Sur–Iro, km 90Photo by Morley Read
EcuadorOrellanaWatiTorres-Carvajal et al. 2019
EcuadorOrellanaYasuní Scientific StationThis work; Fig. 1
EcuadorPastazaArajunoNogueira et al. 2019
EcuadorPastazaBalsauraOrtega-Andrade 2010
EcuadorPastazaCabeceras del Río BobonazaDixon et al. 1993
EcuadorPastazaCampamento K10Torres-Carvajal et al. 2019
EcuadorPastazaCampamento Villano BTorres-Carvajal et al. 2019
EcuadorPastazaCanelosFugler & Walls 1978
EcuadorPastazaCentro Ecológico Zanja ArajunoReptiles of Ecuador book database
EcuadorPastazaComunidad Pablo López de Oglán AltoiNaturalist; photo examined
EcuadorPastazaConamboOrtega-Andrade 2010
EcuadorPastazaDiez de AgostoDixon et al. 1993
EcuadorPastazaHeimatlos LodgePhoto by Ferhat Gundogdu
EcuadorPastazaHuella Verde LodgeThis work; Fig. 1
EcuadorPastazaJuyuintzaTorres-Carvajal et al. 2019
EcuadorPastazaLorocachiOnline multimedia
EcuadorPastazaMeraDixon et al. 1993
EcuadorPastazaMontalvoDixon et al. 1993
EcuadorPastazaOglánTorres-Carvajal et al. 2019
EcuadorPastazaPavacachiUSNM 237010; VertNet
EcuadorPastazaPucayacu (Río Pucayacu)USNM 237005; VertNet
EcuadorPastazaPuyoUSNM 205035; VertNet
EcuadorPastazaRío BobonazaPhoto by Andreas Kay
EcuadorPastazaRío BufeoUSNM 237014; VertNet
EcuadorPastazaRío CurarayUSNM 237010; VertNet
EcuadorPastazaRío LliquinoUSNM 237012; VertNet
EcuadorPastazaRío OglánUSNM 237007; VertNet
EcuadorPastazaRío TalinUSNM 237009; VertNet
EcuadorPastazaSacha YakuReptiles of Ecuador book database
EcuadorPastazaSan Juan de PiatúaTorres-Carvajal et al. 2019
EcuadorPastazaSarayacuDixon et al. 1993
EcuadorPastazaTamandúa ReserveReptiles of Ecuador book database
EcuadorSucumbíosAguarico Protective ForestNogueira et al. 2019
EcuadorSucumbíosBoca del Río CuyabenoUSNM 237003; VertNet
EcuadorSucumbíosComunidad SiugueNogueira et al. 2019
EcuadorSucumbíosDurenoYánez & Chimbo 2007
EcuadorSucumbíosDureno, 18 km N ofNogueira et al. 2019
EcuadorSucumbíosEmbarcadero La Selva LodgeTorres-Carvajal et al. 2019
EcuadorSucumbíosEstación PUCE en CuyabenoNogueira et al. 2019
EcuadorSucumbíosLa Selva Amazon EcolodgeiNaturalist; photo examined
EcuadorSucumbíosLago AgrioKU 300711; VertNet
EcuadorSucumbíosLimoncochaDixon et al. 1993
EcuadorSucumbíosNapo Wildlife CenterReptiles of Ecuador book database
EcuadorSucumbíosPacayacuNogueira et al. 2019
EcuadorSucumbíosPañacochaNogueira et al. 2019
EcuadorSucumbíosPlayas del CuyabenoNogueira et al. 2019
EcuadorSucumbíosPuerto LibreDixon et al. 1993
EcuadorSucumbíosPutumayoOMNH 36519.0; VertNet
EcuadorSucumbíosRío SingüeiNaturalist; photo examined
EcuadorSucumbíosSacha LodgePhoto by Charlie Vogt
EcuadorSucumbíosSani LodgeReptiles of Ecuador book database
EcuadorSucumbíosSanta CeciliaDixon et al. 1993
EcuadorSucumbíosSanta Cecilia, 3 km W ofDixon et al. 1993
EcuadorSucumbíosTarapoaTorres-Carvajal et al. 2019
EcuadorSucumbíosZábaloNogueira et al. 2019
EcuadorZamora ChinchipeBombuscaroTorres-Carvajal et al. 2019
EcuadorZamora ChinchipeCiudad PerdidaDarwin Núñez, pers. comm.
EcuadorZamora ChinchipeCopalingaReeves et al. (unpublished)
EcuadorZamora ChinchipeCumbaratzaNogueira et al. 2019
EcuadorZamora ChinchipeMaycu Nature ReserveThis work; Fig. 1
EcuadorZamora ChinchipeRío ZamoraNogueira et al. 2019
EcuadorZamora ChinchipeTepuy Las OrquídeasNogueira et al. 2019
EcuadorZamora ChinchipeValle del QuimiBetancourt et al. 2018
EcuadorZamora ChinchipeYantzazaNogueira et al. 2019
PeruAmazonasAguaruna villageMVZ 163254; VertNet
PeruAmazonasCabeceras del Río CenepaMVZ 163253; VertNet
PeruAmazonasChiriacoDixon et al. 1993
PeruAmazonasComunidad Nativa CopallinTorres-Carvajal et al. 2019
PeruAmazonasEl CenepaUSNM 316584; VertNet
PeruAmazonasRío SantiagoUSNM 566712; VertNet
PeruAmazonasVicinity of La PozaMVZ 175312; VertNet
PeruLoretoAguas NegrasYánez-Muñoz & Venegas 2008