Inkaterra Vine-Snake (Oxybelis inkaterra)

Reptiles of Ecuador | Serpentes | Colubridae | Oxybelis inkaterra

English common name: Inkaterra Vine-Snake.

Spanish common name: Bejuquilla Inkaterra.

Recognition: ♂♂ 123 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=73.2 cm. ♀♀ 107.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=66.0 cm..¹ Oxybelis inkaterra is easily differentiated from all other snakes in the Ecuadorian Amazon by having an extraordinarily thin and elongated body, a projected and pointed snout, no loreal scale, 17 rows of dorsal scales at mid-body, and a “dry twig” coloration.^1,2 The dorsum is pale grayish-tan with or without small alternating brown spots and blotches (Fig. 1).^1–3 The dorsal aspect of the head is grayish brown with a narrow dull brown ocular stripe.³ This species differs from Xenoxybelis argenteus by having ventral surfaces dingy white heavily obscured by black flecking and blotches (longitudinal dark green lines along the back and belly in the other species).² Males of Oxybelis in general have longer tails than females, but sexual dimorphism has not been confirmed in this species.

Figure 1: Illustration of an adult male of Oxybelis inkaterra based on photographs of Ecuadorian specimens.

Natural history: Oxybelis inkaterra is an extremely rare diurnal and arboreal snake that inhabits pristine terra-firme rainforests.¹ It occurs in areas of dense vegetation as well as in semi-open habitats with shrubby vegetation and sparse canopy as well as along the banks of rivers and streams.^1,2 During the day, Inkaterra Vine-Snakes can be active both at ground level and on bushes up to 1.5 m above the ground.^1–4 A salient defense mechanism of vine snakes in general consists of raising the anterior third of the body in an S-shape while inflating the neck and opening the mouth aggressively.⁴ They are also prone to strike with little provocation. Their bite, though toxic to small prey, is harmless to humans. In Perú, a female of O. inkaterra contained four eggs,² which probably corresponds to the actual clutch size.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances.. Oxybelis inkaterra is a recently described species. Therefore, its conservation status has not yet undergone a formal evaluation by the IUCN Red List. Here, it is proposed to be included in the LC category because the species has a wide distribution spanning large areas of continuous undisturbed habitat as well as many protected areas. Therefore, the species is probably not facing major immediate threats of extinction. Furthermore, the apparent rarity of this snake is probably best explained by its remarkable camouflage and cryptic behavior rather than by low population densities.

Distribution: Oxybelis inkaterra is widely distributed throughout the western Amazon lowlands and adjacent Andean foothills in Colombia, Ecuador (Fig. 2), and Perú.

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

Etymology: The generic name Oxybelis comes from the Greek words oxys (=acute) and belos (=arrow).⁵ The specific epithet inkaterra honors the ecotourism company Inkaterra and its counterpart, a non-profit NGO, Inkaterra Asociación, by promoting education and conservation of Peruvian culture and ecosystems.¹

See it in the wild: The Inkaterra Vine-Snake is an extremely rare species, being recorded no more than once every few years at any given locality. This is probably a combination of naturally low populations and the remarkably elusive behavior and cryptic appearance of the snake. Prime locations for this species include Jatun Sacha Biological Reserve and Yasuní Scientific Station.

Authors: Amanda Quezada^aAffiliation: Tropical Herping (TH), Quito, Ecuador.^,^bAffiliation: Khamai Foundation, Quito, Ecuador. and Alejandro Arteaga^bAffiliation: Khamai Foundation, Quito, Ecuador.

Illustrator: Valentina Nieto Fernández

How to cite? Quezada A, Arteaga A (2024) Inkaterra Vine-Snake (Oxybelis inkaterra). 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/UVUR5916

Literature cited:

Jadin RC, Jowers MJ, Orlofske SA, Duellman WE, Blair C, Murphy JC (2021) A new vine snake (Reptilia, Colubridae, Oxybelis) from Peru and redescription of O. acuminatus. Evolutionary Systematics 5: 1–12. DOI: 10.3897/evolsyst.5.60626
Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
Whitworth A, Beirne C (2011) Reptiles of the Yachana Reserve. Global Vision International, Exeter, 130 pp.
Field notes, Reptiles of Ecuador book project.
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 Oxybelis inkaterra in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

Country	Province	Locality	Source
Colombia	Caquetá	Florencia	Cárdenas Hincapié & Lozano Bernal 2023
Colombia	Caquetá	Isla Mercedes	Calderón et al. 2023
Colombia	Putumayo	Vereda San Bernardo	Ramírez-Chaves et al. 2021
Ecuador	Loreto	Pebas	CAS 12495; VertNet
Ecuador	Morona Santiago	Macuma	iNaturalist; photo examined
Ecuador	Napo	Jatun Sacha Biological Station	Nogueira et al. 2019
Ecuador	Napo	Yachana Reserve	Whitworth & Beirne 2011
Ecuador	Orellana	Napo Wildlife Center	iNaturalist; photo examined
Ecuador	Orellana	Sector San Carlos	MHNG 2442.004; collection database
Ecuador	Orellana	Tiputini Biodiversity Station	Cisneros-Heredia 2003
Ecuador	Orellana	Vía Pompeya Sur–Iro	Torres-Carvajal et al. 2021
Ecuador	Orellana	Yasuní Scientific Station	Reptiles of Ecuador book database
Ecuador	Pastaza	Balsaura	Ortega-Andrade 2010
Ecuador	Pastaza	Río Tigre	Nogueira et al. 2019
Ecuador	Sucumbíos	Cuyabeno River Lodge	Photo by David Buitrón
Ecuador	Sucumbíos	Limoncocha Biological Reserve	UIMNH 54678; collection database
Ecuador	Sucumbíos	San Pablo de Kantesiya	MHNG 2397.067; collection database
Perú	Loreto	Centro Unión	Dixon & Soini 1986
Perú	Loreto	Mishana	Dixon & Soini 1986
Perú	Loreto	Paraíso	Dixon & Soini 1986
Perú	Loreto	Yarina Cocha	Jadin et al. 2021