Published August 31, 2021. Updated March 1, 2024. Open access.

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Red-blotched Ground Snake (Atractus paucidens)

Reptiles of Ecuador | Serpentes | Colubridae | 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 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 (Fig. 1). 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 showing variation among adult individuals of Atractus paucidens

Figure 1: Individuals of Atractus paucidens from Ecuador: Mashpi Lodge, Pichincha province (); Canandé Reserve, Esmeraldas province ().

Natural history: Atractus paucidens is an uncommon semi-fossorial 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, inside rotten logs, or in organic-rich soils where limbs were decomposing.5 Individuals of A. paucidens rely mostly on their cryptic coloration as their main line of defense. A gravid female was found to contain two eggs,5 which probably corresponds to the actual clutch size. Another specimen was being eaten by an Erythrolamprus mimus.7

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Conservation: Vulnerable Considered to be facing a high risk of extinction in the mid-term future..8 Atractus paucidens is listed in this category because the species’ extent of occurrence coincides with areas that are rapidly declining in extent and quality due to deforestation.8 Although the species has a comparatively large distribution, most (~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.9

Distribution: Atractus paucidens is endemic to an area of approximately 30,139 km2 on the Chocoan lowlands and adjacent Andean foothills of western Ecuador (Fig. 2).

Distribution of Atractus paucidens in Ecuador

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 (=spindle),1012 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 comes from the Latin words paucus (=few) and dens (=tooth), and refers to the comparatively low number of maxillary teeth.13

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 valley of the Río Cinto. 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).

Special thanks to Lisa Brunetti for symbolically adopting the Red-blotched Ground Snake and helping bring the Reptiles of Ecuador book project to life.

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Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Photographers: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador. and Sebastián Di DoménicodAffiliation: Keeping Nature, Bogotá, Colombia.

How to cite? Arteaga A (2024) Red-blotched Ground Snake (Atractus paucidens). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/HNOL8421

Literature cited:

  1. 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
  2. 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
  3. 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.
  4. Arteaga A, Bustamante L, Guayasamin JM (2013) The amphibians and reptiles of Mindo. Universidad Tecnológica Indoamérica, Quito, 257 pp.
  5. Field notes, Reptiles of Ecuador book project.
  6. Photo by Alejandro Solano.
  7. Photo by Paul Maier.
  8. Cisneros-Heredia DF, Passos P, Yánez-Muñoz M (2017) Atractus paucidens. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2017-2.RLTS.T50951138A50951143.en
  9. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  10. 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.
  11. Beekes R (2010) Etymological dictionary of Greek. Brill, Boston, 1808 pp.
  12. Duponchel P, Chevrolat L (1849) Atractus. In: d’Orbigny CD (Ed) Dictionnaire universel d’histoire naturelle. MM. Renard, Martinet et Cie., Paris, 312.
  13. 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.

EcuadorCarchiEl PailóniNaturalist; photo examined
EcuadorCotopaxiEl Jardín de los SueñosPhoto by Christophe Pellet
EcuadorEl OroBuenaventura ReserveArteaga et al. 2017
EcuadorEl OroCerro AzulPhoto by Alex Achig
EcuadorEl OroUrna de BuenaventuraReptiles of Ecuador book database
EcuadorEsmeraldasBilsa Biological ReservePhoto by Francisco Sornoza
EcuadorEsmeraldasLote RoseroReptiles of Ecuador book database
EcuadorImbaburaManduriacu ReserveiNaturalist; photo examined
EcuadorManabíLa CrespaiNaturalist; photo examined
EcuadorManabíNovillo, 4 km SE ofiNaturalist; photo examined
EcuadorPichinchaEntre Guayabillas y el Río SardinasiNaturalist; photo examined
EcuadorPichinchaLos Bancos, 1 km N ofiNaturalist; photo examined
EcuadorPichinchaMashpi LodgeReptiles of Ecuador book database
EcuadorPichinchaMouth of Río PitzaráSavage 1960
EcuadorPichinchaPactoLACM 28821; VertNet
EcuadorPichinchaPedro Vicente MaldonadoArteaga et al. 2017
EcuadorPichinchaPuerto QuitoArteaga et al. 2017
EcuadorPichinchaRío CintoArteaga et al. 2017
EcuadorSanta ElenaComuna Loma AltaArteaga et al. 2017
EcuadorSanto Domingo de los TsáchilasFinca la EsperanzaPassos et al. 2009
EcuadorSanto Domingo de los TsáchilasFinca TinalandiaArteaga et al. 2017
EcuadorSanto Domingo de los TsáchilasHacienda GaiboriNaturalist; photo examined
EcuadorSanto Domingo de los TsáchilasParque ChancayiNaturalist; photo examined
EcuadorSanto Domingo de los TsáchilasRecinto La ChimborazoiNaturalist; photo examined
EcuadorSanto Domingo de los TsáchilasSanto Domingo de los Colorados*Savage 1960