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Red-blotched Ground Snake (Atractus paucidens)
Reptiles of Ecuador | Serpentes | Colubridae | Atractus | Atractus paucidens
English common names: Red-blotched Ground Snake, Despax’ Ground Snake.
Spanish common names: Tierrera de manchas rojas, tierrera de Despax, culebra de tierra de pocos dientes.
Recognition: ♂♂ 34 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=29 cm. ♀♀ 47.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=41.9 cm..1,2 The Red-blotched Ground Snake (Atractus paucidens) may be recognized by having a round head similar in width to the neck, small eyes, and a blackish dorsal ground color with 2–7 rounded lateral red blotches restricted to anterior third of body. The blotches may be conspicuous or barely evident.1 The ventral surfaces are white anteriorly, with various degrees of black speckling, and black posteriorly.1,3 In most individuals there is an incomplete white nape band. Atractus paucidens further differs from other ground snakes by having few (5–6) maxillary teeth and a long tail in both sexes, not only in males.1 In the cloud forests of northwestern Ecuador, A. paucidens may be found living alongside A. modestus, a species having a yellow belly and lacking red blotches.4

Figure 1: Individuals of Atractus paucidens from Mashpi Lodge, Pichincha province (), and Canandé Reserve, Esmeraldas province (), Ecuador.
Natural history: UncommonUnlikely to be seen more than once every few months.. Atractus paucidens is a semi-fossorial (living underground and at ground level) snake that inhabits old-growth to moderately-disturbed evergreen forests.2 The species also occurs in rural towns and in areas having a matrix of pastures and forest remnants.5 Red-blotched Ground Snakes are active at dusk or at night, especially after a warm day. Individuals have been seen crossing trails and roads or climbing dirt walls during the day or at night.5,6 When not active, these snakes have been found hidden under rocks or inside rotten logs.5 It is presumed that individuals of A. paucidens rely mostly on their cryptic coloration as their main line of defense.
Conservation: Vulnerable Considered to be facing a high risk of extinction in the mid-term future..7 Atractus paucidens is listed in this category because the species’ extent of occurrence is smaller than 20,000 km2 and its habitat is declining in extent and quality due to deforestation.7 Although the potential distribution area of the species is closer to 30,000 km2 (Fig. 2), ~68% of this area has already been converted to pastures and agricultural fields and each year it loses an additional 254 km2 of forest cover.8 The remaining populations are also severely fragmented and few localities (7 of 21; Appendix 1) are in privately-protected areas.
Distribution: Atractus paucidens is endemic to an estimated 30,139 km2 area on the Chocoan lowlands and adjacent Andean foothills of western Ecuador. The species has been recorded at elevations between 72 and 1402 m (Fig. 2).

Figure 2: Distribution of Atractus paucidens in Ecuador. 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 (meaning “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 paucidens, which comes from the Latin words paucus (meaning “few”) and dens (meaning “tooth”), refers to the comparatively low number of maxillary teeth in this species.12
See it in the wild: Red-blotched Ground Snakes are unlikely to be seen more than once every few months at any given locality. The two areas having the greatest number of observations are the city Santo Domingo and the town El Cinto, nearby Mindo. The snakes may be located by scanning the forest floor and leaf-litter along trails at night or by looking under rocks and logs in pastures nearby forest border.
Acknowledgments: Special thanks to Lisa Brunetti and Matthijs Hollanders for their help in finding individuals of Atractus paucidens. This account was published with the support of Secretaría Nacional de Educación Superior Ciencia y Tecnología (programa INEDITA; project: Respuestas a la crisis de biodiversidad: la descripción de especies como herramienta de conservación; No 00110378), Programa de las Naciones Unidas (PNUD), and Universidad San Francisco de Quito (USFQ).
Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.
Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di DoménicocAffiliation: Keeping Nature, Bogotá, Colombia.
How to cite? Arteaga A (2021) Red-blotched Ground Snake (Atractus paucidens). In: Arteaga A, Bustamante L, Vieira J, Guayasamin JM (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/HNOL8421
Literature cited:
- Passos P, Mueses-Cisneros JJ, Lynch JD, Fernandes R (2009) Pacific lowland snakes of the genus Atractus (Serpentes: Dipsadidae), with description of three new species. Zootaxa 2293: 1–34. DOI: 10.5281/zenodo.191476
- Arteaga A, Mebert K, Valencia JH, Cisneros-Heredia DF, Peñafiel N, Reyes-Puig C, Vieira-Fernandes JL, Guayasamin JM (2017) Molecular phylogeny of Atractus (Serpentes, Dipsadidae), with emphasis on Ecuadorian species and the description of three new taxa. ZooKeys 661: 91–123. DOI: 10.3897/zookeys.661.11224
- 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, Bustamante L, Guayasamin JM (2013) The amphibians and reptiles of Mindo. Universidad Tecnológica Indoamérica, Quito, 257 pp.
- Field notes, Reptiles of Ecuador book project.
- Photo by Alejandro Solano.
- Cisneros-Heredia DF, Passos P, Yánez-Muñoz M (2017) Atractus paucidens. The IUCN red list of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2017-2.RLTS.T50951138A50951143.en
- MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
- 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.
- Despax R (1910) Mission géodésique de l’Équateur. Collections recueillies par M. le Dr. Rivet. Liste des Ophidiens et description des espèces nouvelles. Bulletin du Muséum National d’Histoire Naturelle 16: 368–376. DOI: 10.5962/bhl.part.20432
Appendix 1: Locality data used to create the distribution map of Atractus paucidens 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 | Carchi | El Pailón | iNaturalist |
Ecuador | Cotopaxi | El Jardín de los Sueños | Photo by Christophe Pellet |
Ecuador | El Oro | Buenaventura Reserve | Arteaga et al. 2017 |
Ecuador | El Oro | Cerro Azul | Photo by Alex Achig |
Ecuador | El Oro | Urna de Buenaventura | This work |
Ecuador | Esmeraldas | Bilsa Biological Reserve | Photo by Francisco Sornoza |
Ecuador | Esmeraldas | Lote Rosero | This work |
Ecuador | Imbabura | Manduriacu Reserve | iNaturalist |
Ecuador | Manabí | La Crespa | iNaturalist |
Ecuador | Pichincha | Entre Guayabillas y el Río Sardinas | iNaturalist |
Ecuador | Pichincha | Mashpi Lodge | This work |
Ecuador | Pichincha | Mouth of Río Pitzará | Savage 1960 |
Ecuador | Pichincha | Pacto | LACM 28821 |
Ecuador | Pichincha | Pedro Vicente Maldonado | Arteaga et al. 2017 |
Ecuador | Pichincha | Puerto Quito | Arteaga et al. 2017 |
Ecuador | Pichincha | Río Cinto | Arteaga et al. 2017 |
Ecuador | Santa Elena | Comuna Loma Alta | Arteaga et al. 2017 |
Ecuador | Santo Domingo de los Tsáchilas | Finca la Esperanza | Passos et al. 2009 |
Ecuador | Santo Domingo de los Tsáchilas | Parque Chancay | iNaturalist |
Ecuador | Santo Domingo de los Tsáchilas | Santo Domingo de los Colorados* | Savage 1960 |
Ecuador | Santo Domingo de los Tsáchilas | Tinalandia | Arteaga et al. 2017 |