Published March 9, 2024. Open access.

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Mountain Whipsnake (Chironius monticola)

Reptiles of Ecuador | Serpentes | Colubridae | Chironius monticola

English common names: Mountain Whipsnake, Andean Whipsnake, Mountain Sipo.

Spanish common names: Serpiente látigo montañera, sipo de montaña (Ecuador); lomo de machete, juetiadora (Colombia).

Recognition: ♂♂ 156.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=101.4 cm. ♀♀ 131.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=85.9 cm..1 Chironius monticola differs from other species of Chironius by having the following combination of characters: 12 rows of dorsal scales at mid-body, an entire anal plate, no apical pits, and a unique coloration.1,2 The dorsal surfaces are uniformly green with a pair of black stripes along the tail (absent in some Ecuadorian specimens; Fig. 1).1,2 This species differs from C. exoletus by the presence of black stripes on the tail and an entire anal plate.1 From C. leucometapus, it differs by having 12, instead of 10, dorsal scale rows.3

Figure showing variation among individuals of Chironius monticola

Figure 1: Individuals of Chironius monticola: Narupa Reserve, Napo province, Ecuador (); Garagoa, Boyacá department, Colombia (); Yanayacu Biological Station, Napo province, Ecuador ().

Natural history: Chironius monticola is a semi-arboreal snake with a diurnal activity pattern. This species usually inhabits cloud forests, but also occurs in seasonally dry montane forest and paramo ecosystems.1,2 It appears to occur in higher densities in semi-open habitats such as along forest borders, in clearings, pastures with scattered trees, and even around rural areas.4,5 Mountain Whipsnakes are more active during sunny periods in otherwise cloudy environments.4 Most observation are of snakes crossing forest trails, roads, grassy fields, water bodies, or individuals frantically foraging at ground level or on trees.4 Curiously, one was submerged 1 m deep in a cold-water river.6 At night or during cold weather, these snakes remain coiled on branches up to 4 m above the ground, sometimes near streams,1,4 or in terrestrial bromeliads.2 One individual was spotted in the canopy at 40 m above the ground.7 Chironius monticola has one of the most generalist diets in the genus, feeding not only on frogs (the preferred prey item, including Pristimantis w-nigrum,8,9),1 but also on birds, rodents, and lizards.1,10 The Mountain Whipsnake, when disturbed, can exhibit an aggressive behavior which consists of raising the first third of the body while striking repeatedly.1,4 However, this is an aglyphous snake, meaning it lacks venom-inoculating teeth.1 There are recorded instances of predation on members of this species, including by eagles and the toucan Andigena laminirostris in Ecuador.4 In Colombia, male-male combat was observed. The clutch size in this species consists of 3–8 eggs.2

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..11 Chironius monticola is listed in this category primarily because the species is widely distributed, occurs in protected areas, and is able to tolerate some degree of habitat disturbance so long as forest remains.11 However, this species can be particularly affected by traffic, being frequently found dead-on-road in Ecuador12 and Colombia.13,14 Also, the indiscriminate killing of snakes may be a factor in the decline of some populations of this species.

Distribution: Chironius monticola is widespread throughout the tropical Andes, being found in Venezuela, Colombia, Perú, Bolivia, and Ecuador (Fig. 2). The species is found mainly on the eastern slopes of the Andes, but in Ecuador and Colombia, it also inhabits the western slopes.

Distribution of Chironius monticola in Ecuador

Figure 2: Distribution of Chironius monticola 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.15 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. The specific epithet monticola is a Latin word meaning “dweller of the mountains.”1

See it in the wild: Mountain Whipsnakes, though uncommon throughout the majority of their distribution, are frequently encountered along the valleys of the Río Quijos and upper Río Pastaza, particularly in Reserva Narupa and Reserva La Candelaria. These snakes are most easily spotted on vegetation along water bodies at night or at ground level in semi-open areas during sunny mornings.

Special thanks to Joanne Green for symbolically adopting the Mountain Whipsnake and helping bring the Reptiles of Ecuador book project to life.

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Authors: Esteban Garzón-FrancoaAffiliation: Colecciones Biológicas de la Universidad CES (CBUCES), Facultad de Ciencias y Biotecnología, Universidad CES, Medellín, Colombia. and Laura Gómez-Mesa,bAffiliation: Escuela de Ciencias Aplicadas e Ingeniería, Universidad EAFIT, Medellín, Colombia. and Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.

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

How to cite? Garzón-Franco E, Gómez-Mesa L, Arteaga A (2024) Mountain Whipsnake (Chironius monticola). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/SNTY2753

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. La Marca E, Soriano PJ (2004) Reptiles de los Andes de Venezuela. Fundación Polar, Mérida, 173 pp.
  3. 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
  4. Field notes, Reptiles of Ecuador book project.
  5. Rojas-Morales JA (2012) Snakes of an urban-rural landscape in the central Andes of Colombia: species composition, distribution, and natural history. Phyllomedusa 11: 135–154.
  6. Grajales Echeverry A, de Plecker R, Duarte-Marín S (2022) Chironius monticola (Andean Whip Snake): behavior. Herpetological Review 53: 693.
  7. Manzanilla J, Fernández-Badillo A, Visbal R (1996) Fauna del Parque Nacional Henry Pittier, Venezuela: composición y distribución de los reptiles. Acta Científica Venezolana 47: 191–204.
  8. Ramírez-Jaramillo SM, Pozo-Zamora GM (2020) Notas del comportamiento predatorio e ingestión de Chironius monticola (Serpentes: Colubridae) en el suroccidente del Ecuador. Neotropical Biodiversity 6: 37–41. DOI: 10.1080/23766808.2020.1730548
  9. Photo by Eduardo Obando.
  10. Roberto IJ, Souza AR (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.
  11. Daza J, Aguayo R, Aparicio J, Gonzales L, Embert D, Cisneros-Heredia DF, Valencia J, Venegas P, Rivas G (2016) Chironius monticola. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2016-1.RLTS.T44580132A44580137.en
  12. Medrano Vizcaíno PM (2015) Efecto de las carreteras en la mortalidad de vertebrados en un área megadiversa: los Andes Tropicales del Ecuador. MSc thesis, Pontificia Universidad Católica del Ecuador, 50 pp.
  13. Esteban Garzón-Franco, field observation.
  14. Castillo JC, Urmendez D, Zambrano G (2015) Mortalidad de fauna por atropello vehicular en un sector de la vía Panamericana entre Popayán y Patía. Boletín Científico, Centro de Museos, Museo de Historia Natural 19: 207–219. DOI: 10.17151/bccm.2015.19.2.12
  15. Merrem B (1790) Beitrage zur Naturgeschichte. Duisburg um Lemgo, Berlin, 141 pp.

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

ColombiaNariñoMallamaiNaturalist; photo examined
ColombiaNariñoPiedrancha, 5 km NW ofDixon et al. 1993
ColombiaNariñoReserva Natural La PlanadaSantander Oliva et al. 2023
ColombiaNariñoRicaurteiNaturalist; photo examined
ColombiaPutumayoVereda El PorotaliNaturalist; photo examined
EcuadorAzuayMolleturoReptiles of Ecuador book database
EcuadorAzuayRío ChiplaRodríguez-Guerra et al. 2020
EcuadorAzuayZhiumirColección AMARU
EcuadorCañarMazarMZUA.RE.0045; examined
EcuadorCarchiChilma BajoTorres-Carvajal et al. 2018
EcuadorCarchiQuinshulliNaturalist; photo examined
EcuadorCarchiRoad Maldonado–TulcánTorres-Carvajal et al. 2018
EcuadorCarchiSector La PlataRodríguez-Guerra et al. 2020
EcuadorChimborazoPallatangaDixon et al. 1993
EcuadorEl OroChilla–GuanazánReptiles of Ecuador book database
EcuadorEl OroEl BirónRamírez-Jaramillo & Pozo-Zamora 2020
EcuadorEl OroMirador de ChillaiNaturalist; photo examined
EcuadorImbaburaAbove PimampiroReptiles of Ecuador book database
EcuadorImbaburaCahuasquíReptiles of Ecuador book database
EcuadorImbaburaLa Merced de Buenos AiresPhoto by Jesse Kimmerling
EcuadorImbaburaPucará, 2 km E ofReptiles of Ecuador book database
EcuadorLojaCelica, 1 km W ofTorres-Carvajal et al. 2018
EcuadorLojaLoja, 5 km E ofDixon et al. 1993
EcuadorMorona SantiagoEl Ideal, 16 km N ofTorres-Carvajal et al. 2018
EcuadorMorona SantiagoMacas, environs ofDixon et al. 1993
EcuadorMorona SantiagoPlan de Milagro, 7 km W ofTorres-Carvajal et al. 2018
EcuadorMorona SantiagoReserva Biológica El QuimiRodríguez-Guerra et al. 2020
EcuadorMorona SantiagoReserva TinajillasReptiles of Ecuador book database
EcuadorNapoBaezaAMNH 110583; examined
EcuadorNapoBaeza, 5 km S ofDixon et al. 1993
EcuadorNapoBorjaDixon et al. 1993
EcuadorNapoCuyuja–CocodriloReptiles of Ecuador book database
EcuadorNapoEl ChacoReptiles of Ecuador book database
EcuadorNapoNarupa ReserveThis work; Fig. 1
EcuadorNapoRío AzuelaDixon et al. 1993
EcuadorNapoRío JondachiiNaturalist; photo examined
EcuadorNapoSan RafaelMHNG 2412.037; collection database
EcuadorNapoSanta Rosa, 5 km NNE ofDixon et al. 1993
EcuadorNapoSumaco Camp MiradorMZUTI 5553; examined
EcuadorNapoWildsumaco Wildlife SanctuaryCamper et al. 2021
EcuadorNapoYanayacu Biological StationThis work; Fig. 1
EcuadorPastazaAbitaguaCAS 8264; VertNet
EcuadorPastazaMera, environs ofDixon et al. 1993
EcuadorSucumbíosEl ReventadorPhoto by Diego Piñán
EcuadorSucumbíosLa BonitaTorres-Carvajal et al. 2019
EcuadorSucumbíosLa PlayaReptiles of Ecuador book database
EcuadorTungurahuaBaños de Agua SantaDixon et al. 1993
EcuadorTungurahuaBelow El TriunfoReptiles of Ecuador book database
EcuadorTungurahuaEl TopoReptiles of Ecuador book database
EcuadorTungurahuaPuntzanReptiles of Ecuador book database
EcuadorTungurahuaReserva La CandelariaReptiles of Ecuador book database
EcuadorTungurahuaRío VerdeErnesto Arbeláez, pers. comm.
EcuadorTungurahuaSan Francisco de MapotoDixon et al. 1993
EcuadorTungurahuaSan Pablo, vía a El TriunfoTorres-Carvajal et al. 2018
EcuadorZamora ChinchipeEstación San FranciscoMZUA.RE.0160; examined
EcuadorZamora ChinchipeNangaritzaReptiles of Ecuador book database
EcuadorZamora ChinchipeReserva Biológica Cerro PlateadoTorres-Carvajal et al. 2018
EcuadorZamora ChinchipeReserva Forestal El ZarzaiNaturalist; photo examined
EcuadorZamora ChinchipeSan RamónTorres-Carvajal et al. 2018
EcuadorZamora ChinchipeTres AguasPhoto by Diana Encalada
EcuadorZamora ChinchipeZumba, 24 km W ofTorres-Carvajal et al. 2018
PeruAmazonasAnexo San PedroTorres-Carvajal et al. 2018
PeruAmazonasBase of Cerro MachinazaUSNM 525555; VertNet
PeruAmazonasCampamento IngenioDixon et al. 1993
PeruAmazonasCatara GoctaiNaturalist; photo examined
PeruAmazonasDistrito Vista AlegreTorres-Carvajal et al. 2018
PeruAmazonasLeimebamba, 14 km NNE ofDixon et al. 1993
PeruAmazonasOwlet LodgeiNaturalist; photo examined
PeruLoretoYanagaenDixon et al. 1993
PeruPiuraHuancabambaDixon et al. 1993
PeruPiuraPeña RicaTorres-Carvajal et al. 2018
PeruSan MartínFront range between Moyobamba and Río MarañónDixon et al. 1993
PeruSan MartínRoad Laurel–Los ChichosTorres-Carvajal et al. 2018