Andean Forest-Pitviper (Bothrops pulcher)

Reptiles of Ecuador | Serpentes | Viperidae | Bothrops pulcher

English common name: Andean Forest-Pitviper.

Spanish common name: Víbora loro mashaco.

Recognition: ♂♂ 77.2 cmMaximum distance from the snout to the tip of the tail. ♀♀ 99.6 cmMaximum distance from the snout to the tip of the tail.. Bothrops pulcher can be distinguished from other sympatric vipers—characterized by triangular heads and presence of loreal pits—by its prehensile tail and a striking dorsal pattern of 29–37 pale-edged blackish bands or blotches on a greenish ground color (Fig. 1).¹ This species differs from B. taeniatus by its lack of bold black speckling on the iris and by possessing prominent, elevated keels on the dorsal scales (which are lower in B. taeniatus). It is distinguished from B. bilineatus by its banded pattern, whereas B. bilineatus features a predominantly uniform green dorsum with distinct pale lateral stripes along the lower flanks.¹

Figure showing variation among individuals of Bothrops pulcher

Figure 1: Individuals of Bothrops pulcher from Amazonian Ecuador: Río Bigal Reserve, Orellana province (); Narupa Reserve, Napo province (). j=juvenile.

Natural history: Bothrops pulcher is an uncommonly encountered arboreal pitviper that inhabits old-growth to moderately disturbed evergreen montane forests, forest edges, and agricultural plantations (e.g., cassava and naranjilla).^2,3 Andean Forest-Pitvipers are primarily nocturnal, with activity peaking after warm days.⁴ While they are typically found coiled on vegetation between 0.6 and 6 m above the ground, individuals have been observed traversing the forest floor during periods of heavy rainfall.⁴ During daylight hours, they remain sedentary and well-camouflaged on elevated perches.³ As ambush predators, these vipers exhibit a specialized ontogenetic shift in diet and hunting strategy. Juveniles employ caudal luring—using their brightly colored tail-tips to attract invertebrates—whereas adults transition to a diet of frogs and rodents.² Defensively, B. pulcher relies on crypsis but will strike readily if harassed. Distinctively, this species can extend nearly its entire body length during a strike while anchored to a perch solely by its prehensile tail-tip.² This species is venomous and medically significant. In humans, envenomation causes intense localized pain, hemorrhaging, and severe edema, with potential fatalities if untreated; however, “dry bites” (defensive strikes without venom inoculation) have been documented.² The species is ovoviviparous, with females giving birth to live young (typically 13–14 offspring).^5,6 While wild longevity is unknown, a captive specimen at the Vivarium in Quito reached a recorded age of five years.²

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

Conservation: Least Concern Believed to be safe from extinction given current circumstances..⁷ Bothrops pulcher is listed in this category primarily due to its relatively broad distribution across regions that maintain a high percentage of their original forest cover. It is estimated that approximately 79.5% of the species’ potential habitat in Ecuador remains pristine, suggesting it faces no immediate risk of extinction. However, long-term stability is threatened by localized habitat destruction driven by mining operations and the expansion of the agricultural frontier.² Additionally, direct human persecution remains a significant source of mortality; due to their venomous nature, these vipers are frequently killed on sight when encountered in rural and agricultural areas.

Distribution: Bothrops pulcher is native to an estimated area of 52,972 km² spanning the Amazonian foothills of the Andes. Its range extends from southern Colombia through the eastern slopes of Ecuador and into northeastern Perú. In Ecuador, the species is primarily distributed along the humid lower-montane forests of the Oriente, occupying a transitional elevational belt between the lowland rainforest and the higher Andean cloud forests.

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

Etymology: The generic name Bothrops is derived from the Greek word bothros (meaning “pit”),⁸ a direct reference to the specialized loreal heat-sensing pits located between the eyes and nostrils. The specific epithet pulcher is a Latin adjective meaning “beautiful,” referring to the vivid dorsal color pattern characteristic of this species.¹

Where to observe: In Ecuador, Bothrops pulcher is uncommonly encountered, with a typical detection rate of approximately once every few months within suitable habitat. The most reliable localities for observing this species include the Narupa Reserve, Wildsumaco Wildlife Sanctuary, Río Zuñac Reserve, and San Francisco Biological Reserve. These vipers are most effectively located by conducting nocturnal surveys, specifically by scanning understory vegetation along well-preserved forest trails.

Special thanks to Thomas Kelafant, Michael Meyer, and Jennifer Roger for symbolically adopting the Andean Forest-Pitviper and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Author: Alejandro Arteaga^aAffiliation: Fundación Khamai, Reserva Arlequín, Ecoruta Paseo del Quinde km 56, Santa Rosa de Mindo, Pichincha 171202, Ecuador.

Photographer: Jose Vieira^bAffiliation: Tropical Herping (TH), Quito, Ecuador.^,^cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2026) Andean Forest-Pitviper (Bothrops pulcher). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/BXQA8420

Literature cited:

Campbell JA, Lamar WW (2004) The venomous reptiles of the western hemisphere. Cornell University Press, Ithaca, 774 pp.
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.
Field notes of Jose Simbaña.
Field notes, Reptiles of Ecuador book project.
Field notes of Ernesto Arbeláez.
Field notes of Darwin Núñez.
Ines Hladki A, Ramírez Pinilla M, Renjifo J, Urbina N, Cisneros-Heredia DF, Yánez-Muñoz M (2021) Bothrops pulcher. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2021-3.RLTS.T15203715A15203723.en
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 Bothrops pulcher in Ecuador (Fig. 2).

Country	Province	Locality	Source
Colombia	Caquetá	Florencia	iNaturalist; photo examined
Colombia	Caquetá	Guacamaya	iNaturalist; photo examined
Colombia	Caquetá	San Vicente del Caguán, environs of	Photo by Andrés Ortiz
Colombia	Cauca	San Juan de Villalobos	Ayerbe et al. 2007
Colombia	Cauca	Santa Rosa	iNaturalist; photo examined
Colombia	Cauca	Vía Mocoa–Neiva	iNaturalist; photo examined
Colombia	Putumayo	Mocoa, 7 km W of	iNaturalist; photo examined
Colombia	Putumayo	Mocoa, environs of	Campbell & Lamar 2004
Colombia	Putumayo	Rincón del Vides	Campbell & Lamar 2004
Ecuador	Loja	Loja, 6 km E of	Valencia et al. 2016
Ecuador	Morona Santiago	Agett-Geary Reserve	iNaturalist; photo examined
Ecuador	Morona Santiago	Bosque Medicinal	Reptiles of Ecuador book database
Ecuador	Morona Santiago	Central Hidroeléctrica Abanico	Valencia et al. 2016
Ecuador	Morona Santiago	Centro Shuar Kiim	Valencia et al. 2016
Ecuador	Morona Santiago	Chiguaza	Valencia et al. 2016
Ecuador	Morona Santiago	Comunidad Amazonas	Reptiles of Ecuador book database
Ecuador	Morona Santiago	Copal	iNaturalist; photo examined
Ecuador	Morona Santiago	Laguna el Enmascarado	Photo by Darwin Núñez
Ecuador	Morona Santiago	Loma del Tigrillo	iNaturalist; photo examined
Ecuador	Morona Santiago	Macas	Valencia et al. 2016
Ecuador	Morona Santiago	Makuma	Valencia et al. 2016
Ecuador	Morona Santiago	Patuca	Photo by Darwin Núñez
Ecuador	Morona Santiago	Puchimi	Rodríguez-Guerra 2019
Ecuador	Morona Santiago	San Juan Bosco	Photo by Saúl Duchitanga
Ecuador	Morona Santiago	Sardinayacu	Valencia et al. 2016
Ecuador	Morona Santiago	Sardinayacu, Laguna Chimerella	Valencia et al. 2016
Ecuador	Morona Santiago	Sopladora	Juan Carlos Sánchez
Ecuador	Morona Santiago	Timias	Valencia et al. 2016
Ecuador	Napo	Hidroeléctrica Coca Codo Sinclair	Valencia et al. 2016
Ecuador	Napo	Narupa Reserve	This work; Fig. 1
Ecuador	Napo	Narupayacu	Photo by José Simbaña
Ecuador	Napo	Pacto Sumaco	Valencia et al. 2016
Ecuador	Napo	Sendero Cocodrilos	Valencia et al. 2016
Ecuador	Napo	Wild Sumaco Wildlife Sanctuary	Valencia et al. 2016
Ecuador	Orellana	Río Bigal Biological Reserve	This work; Fig. 1
Ecuador	Pastaza	Arajuno	Valencia et al. 2016
Ecuador	Pastaza	Cabeceras del Río Bobonaza	Valencia et al. 2016
Ecuador	Pastaza	Río Anzu	Valencia et al. 2016
Ecuador	Pastaza	Río Arajuno	Valencia et al. 2016
Ecuador	Pastaza	Río Copataza	Valencia et al. 2016
Ecuador	Pastaza	Río Lliquino	Valencia et al. 2016
Ecuador	Pastaza	Río Oglán	Valencia et al. 2016
Ecuador	Pastaza	Río Rutuno	Valencia et al. 2016
Ecuador	Pastaza	Shell	Valencia et al. 2016
Ecuador	Pastaza	Sumak Kawsay In Situ	iNaturalist; photo examined
Ecuador	Pastaza	Washents	Valencia et al. 2016
Ecuador	Tungurahua	El Placer	Valencia et al. 2016
Ecuador	Tungurahua	La Candelaria Reserve	Valencia et al. 2016
Ecuador	Tungurahua	Río Blanco	Valencia et al. 2016
Ecuador	Tungurahua	Río Chinchín	Reptiles of Ecuador book database
Ecuador	Tungurahua	Río Negro	KU 121348; Motta & Brown 2026
Ecuador	Tungurahua	Río Verde	Valencia et al. 2016
Ecuador	Tungurahua	Río Zuñac	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Bosque Protector Yacuambi	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Campamento Militar Cóndor–Mirador	Photo by Ernesto Arbeláez
Ecuador	Zamora Chinchipe	Chinapitza	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Chorrillos	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Concesión Colibrí	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Concesión Minera Emperador	Valencia et al. 2016
Ecuador	Zamora Chinchipe	El Líbano	Valencia et al. 2016
Ecuador	Zamora Chinchipe	El Zarza	iNaturalist; photo examined
Ecuador	Zamora Chinchipe	Estación Científica San Francisco	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Los Encuentros	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Maycu	Photo by Ernesto Arbeláez
Ecuador	Zamora Chinchipe	Nambija	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Paquisha	Reptiles of Ecuador book database
Ecuador	Zamora Chinchipe	Paquisha Alto	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Proyecto Cóndor Mirador	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Reserva Biológica Cerro Plateado	iNaturalist; photo examined
Ecuador	Zamora Chinchipe	Tapichalaca Reserve	Valencia et al. 2016
Ecuador	Zamora Chinchipe	Tundayme–Condor Mirador	Photo by Sebastián Padrón
Ecuador	Zamora Chinchipe	Yawi	Photo by Darwin Núñez
Ecuador	Zamora Chinchipe	Zumba	Valencia et al. 2016
Perú	Amazonas	Cordillera de Colán National Sanctuary	iNaturalist; photo examined
Perú	Amazonas	Cordillera del Yolán	Photo by Rainer Schulte
Perú	Amazonas	La Peca, 12 km E of	LSUMZ 39316; VertNet
Perú	Amazonas	Rioja	iNaturalist; photo examined
Perú	Amazonas	Valdivia, environs of	Campbell & Lamar 2004
Perú	Cajamarca	Bosques El Chaupe, Cunía y Chinchiquilla	Online report by NCI
Perú	Cajamarca	Caserío Pueblo Libre	iNaturalist; photo examined
Perú	Cajamarca	Limit between Cajamarca and Amazonas	Tomba 2019
Perú	Cajamarca	Los Cuyes	Tomba 2019
Perú	Cajamarca	Santa Rosa	Campbell & Lamar 2004
Perú	Cajamarca	Santuario Nacional Tabaconas Namballe	Tomba 2019
Perú	Loreto	Subteniente Castro	Campbell & Lamar 2004
Perú	San Martín	Rioja	iNaturalist; photo examined