Ecuadorian Ground Snake (Atractus ecuadorensis)

Reptiles of Ecuador | Serpentes | Colubridae | Atractus ecuadorensis

English common name: Ecuadorian Ground Snake.

Spanish common name: Tierrera ecuatoriana.

Recognition: ♂♂ 24.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=19.8 cm..¹ Atractus ecuadorensis differs from other co-occurring snakes by having a round head similar in width to the neck, small eyes, and a striped pattern (Fig. 1). The dorsal surfaces are uniformly dark brown with six continuous longitudinal dark lines.^1,2 The belly is bright yellow and lacks longitudinal black lines.^1,2 Unlike A. gaigeae and A. collaris, individuals of A. ecuadorensis lack a series of dark spots accompanying the black lines.^1,2 This species resembles A. zgap in both coloration and scale counts, but the latter is restricted to the valley of the Río Quijos and is characterized by having a lower number of dorsal stripes (five instead of six or seven) and less than 40 subcaudal scales in males.³

Ilustration of an adult male of Atractus ecuadorensis

Figure 1: Illustration of an adult male of Atractus ecuadorensis based on the holotype.

Natural history: Atractus ecuadorensis is an extremely rare semi-fossorial snake that inhabits old-growth to moderately-disturbed lower-montane forests.^1,2 One individual was captured in a pitfall trap in the forest at night, but there is no more information about the habits of this species.⁴ Based on what is known about other ground snakes, the diet in A. ecuadorensis probably includes earthworms and slugs.^5–7

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Conservation: Data Deficient There is inadequate information to make an assessment of extinction risk..⁸ Atractus ecuadorensis is included in this category because the species belongs to a poorly studied genus of snakes and is known from less than 10 specimens collected primarily in the immediate environs of the type locality. Therefore, there is inadequate information to make an assessment of the extinction risk of this species based on its scarce distribution data. However, A. ecuadorensis occurs in protected areas (Llanganates National Park) and is more widespread that previously thought (Fig. 2). The DD assignment is an important alarm to increase the knowledge about this poorly-known serpent.

Distribution: Atractus ecuadorensis is endemic to an area of approximately 2,356 km² along the Amazonian slopes of the Andes of central Ecuador (Fig. 2).

Figure 2: Distribution of Atractus ecuadorensis in Ecuador. The star corresponds to the type locality: Llanganates, Pastaza province. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The name Atractus, which is a latinization of the Greek word άτρακτος (=spindle),^9–11 probably refers to the fact that snakes of this genus have a uniform width throughout the body and a narrow tail, resembling an antique spindle used to spin fibers. The specific epithet ecuadorensis refers to Ecuador.¹

See it in the wild: Atractus ecuadorensis is one of Ecuador’s rarest snakes. The most precise recent records are from Río Verde, Tungurahua province, and Sumak Kawsay In Situ, Pastaza province. It is presumed that these snakes may be detected by scanning the forest floor and leaf-litter along trails at night or by turning over rocks and logs in clearings near forest borders.

Authors: Duvan Zambrano^aAffiliation: Universidad del Tolima, Ibagué, Colombia. and Alejandro Arteaga^bAffiliation: Khamai Foundation, Quito, Ecuador.

Illustrator: Valentina Nieto Fernández

How to cite? Zambrano D, Arteaga A (2024) Ecuadorian Ground Snake (Atractus ecuadorensis). 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/QJBO4569

Literature cited:

Savage JM (1955) Descriptions of new colubrid snakes, genus Atractus, from Ecuador. Proceedings of the Biological Society of Washington 68: 11–20.
Savage JM (1960) A revision of the Ecuadorian snakes of the Colubrid genus Atractus. Miscellaneous Publications, Museum of Zoology, Univesity of Michigan 112: 1–184.
Arteaga A, Quezada A, Vieira J, Guayasamin JM (2022) Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach. ZooKeys 1121: 175–210. DOI: 10.3897/zookeys.1121.89539
Photo by Evelyn Estefanía Pilozo.
Cisneros-Heredia DF (2005) Report of molluscivory in Atractus carrioni Parker, 1930. Herpetozoa 18: 185–186.
Balestrin RL, Di-Bernardo M, Moreno AG (2007) Feeding ecology of the neotropical worm snake Atractus reticulatus in southern Brazil. The Herpetological Journal 17: 62–64.
Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
Cisneros-Heredia DF, Valencia J (2016) Atractus ecuadorensis. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2016-1.RLTS.T50951080A50951085.en
Woodward SP, Tate R (1830) A manual of the Mollusca: being a treatise on recent and fossil shells. C. Lockwood and Company, London, 750 pp.
Beekes R (2010) Etymological dictionary of Greek. Brill, Boston, 1808 pp.
Duponchel P, Chevrolat L (1849) Atractus. In: d’Orbigny CD (Ed) Dictionnaire universel d’histoire naturelle. MM. Renard, Martinet et Cie., Paris, 312.

Appendix 1: Locality data used to create the distribution map of Atractus ecuadorensis in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

Country	Province	Locality	Source
Ecuador	Morona Santiago	Normandía	AMNH 28787; VertNet
Ecuador	Morona Santiago	Plan de Milagro at 1200 m	QCAZ 2013; examined
Ecuador	Morona Santiago	Riobamba–Normandía	AMNH 35932; VertNet
Ecuador	Pastaza	Peter Archer’s place	Photo by Yatin Kalki
Ecuador	Pastaza	Sumak Kawsay In Situ	Bentley et al. 2021
Ecuador	Tungurahua	Llanganates area*	Savage 1955
Ecuador	Tungurahua	Pailón del Diablo	Cisneros-Heredia & Valencia 2016
Ecuador	Tungurahua	Río Machay	Arteaga et al. 2017
Ecuador	Tungurahua	Río Verde	Arteaga et al. 2017
Ecuador	Tungurahua	Río Verde, 2.5 km S of	iNaturalist; photo examined