Published August 16, 2021. Updated February 16, 2024. Open access.

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Lojan Ground Snake (Atractus carrioni)

Reptiles of Ecuador | Serpentes | Colubridae | Atractus carrioni

English common names: Lojan Ground Snake, Parker’s Ground Snake, Carrión’s Ground Snake.

Spanish common names: Tierrera lojana, tierrera de Carrión, culebra minadora lojana.

Recognition: ♂♂ 40 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=35 cm. ♀♀ 55.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=49.5 cm.. Atractus carrioni can be recognized by having a round head similar in width to the neck, small eyes, dorsal scales arranged in 15 rows at mid-body, and a uniformly sepia or dark brown dorsal coloration (Fig. 1).13 This dorsal pattern is shared with other members of the genus, but A. carrioni is distinguishable by having a dark brown belly and lacking a loreal scale. Generally, this is the only Atractus occurring in the southwestern Ecuadorian Andes.2,3 A morphologically similar species is A. roulei, a snake which usually has a loreal scale and occurs north of the known distribution of A. carrioni.1,2 Males of A. carrioni differ from females by having a proportionally longer tail.2

Figure showing variation among adult individuals of Atractus carrioni

Figure 1: Individuals of Atractus carrioni from Alamor () and Loja (), Loja province, Ecuador.

Natural history: Atractus carrioni is a locally abundant semi-fossorial snake that inhabits humid to seasonally dry montane shrublands with various degrees of human intervention.4,5 The species also occurs in the border between pastures and patches of native forest,5 remnants of vegetation in the city, or in urban green spaces.4,6 Lojan Ground Snakes can be found active at night at ground level, crossing roads, rural trails, or on leaf-litter.5,6 They appear to be more common in March, at the peak of the rainy season.6 When not active, these snakes can be found hidden under rocks,3 rotten logs, buried in the ground, or in crevices.5,6 Ground snakes feed primarily on earthworms; however, specimens of A. carrioni have been found to feed on slugs.7 Although these appear to be different diets, A. carrioni has no obvious morphological differences from other members of the genus. Therefore, it is likely that A. carrioni feeds sporadically on slugs when they are an abundant resource.7 The defensive behavior in the Lojan Ground Snake consists mainly of trying to flee upon detecting a threat.5 Individuals also use camouflage to go unnoticed. Females containing 3–5 eggs have been found,3 but the real clutch size is unknown.

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Conservation: Endangered Considered to be facing a high risk of extinction in the near future..8,9 Atractus carrioni is listed in this category because the species has a small (around 5,293 km2) distribution range that has been severely affected by agricultural practices.8 Based on maps of Ecuador’s vegetation cover published in 2012,10 the majority (~59%) of the species’ potential distribution in Ecuador is now devoid of native vegetation and no more than ~4% of the total extent of occurrence in the country is in protected areas. Furthermore, individuals are also persecuted for use in traditional medicine8 or killed by vehicular traffic.3,6

Distribution: Atractus carrioni is native to an area of approximately 5,293 km2 in the Pacific slopes of the Andes in southwestern Ecuador (Fig. 2) and northwestern Perú.

Distribution of Atractus carrioni in Ecuador

Figure 2: Distribution of Atractus carrioni in Ecuador. The star corresponds to the type locality: Loja, Loja 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),1113 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 carrioni honors Professor Clodoveo Carrión Mora (1883–1957), an Ecuadorian naturalist and paleontologist who collected the holotype of the species.14

See it in the wild: Lojan Ground Snakes can be seen with almost complete certainty in rural areas around Loja city or in Utuana Reserve, so long as the search is targeted and in suitable habitats. The snakes may be detected by scanning the forest floor and leaf-litter along dirt roads at night, or by turning over rocks and logs in pastures near remnants of native vegetation during the daytime.

Acknowledgments: Special thanks to Darwin Núñez and Hernán Orellana for providing natural history data on Atractus carrioni.

Special thanks to Angelika Lange for symbolically adopting the Lojan Ground Snake and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

Author: Duvan ZambranoaAffiliation: Universidad del Tolima, Ibagué, Colombia.

Editor: Alejandro ArteagabAffiliation: Tropical Herping (TH), Quito, Ecuador.

Photographer: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador.

How to cite? Zambrano D (2021) Lojan Ground Snake (Atractus carrioni). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/HXAF2252

Literature cited:

  1. 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
  2. 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.
  3. Passos P, Echevarría LY, Venegas PJ (2013) Morphological variation of Atractus carrioni (Serpentes: Dipsadidae). South American Journal of Herpetology 8: 109–120. DOI: 10.2994/SAJH-D-12-00025.1
  4. Hernán Orellana, pers. comm.
  5. Field notes, Reptiles of Ecuador book project.
  6. Darwin Núñez, pers. comm.
  7. Cisneros-Heredia DF (2005) Report of molluscivory in Atractus carrioni Parker, 1930. Herpetozoa 18: 185–186.
  8. Cisneros-Heredia DF (2016) Atractus carrioni. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2016-1.RLTS.T50951041A50951046.en
  9. Carrillo E, Aldás A, Altamirano M, Ayala F, Cisneros-Heredia DF, Endara A, Márquez C, Morales M, Nogales F, Salvador P, Torres ML, Valencia J, Villamarín F, Yánez-Muñoz M, Zárate P (2005) Lista roja de los reptiles del Ecuador. Fundación Novum Millenium, Quito, 46 pp.
  10. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  11. 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.
  12. Beekes R (2010) Etymological dictionary of Greek. Brill, Boston, 1808 pp.
  13. Duponchel P, Chevrolat L (1849) Atractus. In: d’Orbigny CD (Ed) Dictionnaire universel d’histoire naturelle. MM. Renard, Martinet et Cie., Paris, 312.
  14. Parker HW (1930) A new colubrine snake from Ecuador. Annals and Magazine of Natural History 5: 207–209. DOI: 10.1080/00222933008673120

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

EcuadorLojaAlamorThis work; Fig. 1
EcuadorLojaAlgodonaliNaturalist; photo examined
EcuadorLojaHacienda JipiroUSNM 217607; VertNet
EcuadorLojaJacapoField notes of Néstor Acosta
EcuadorLojaJorupe ReserveiNaturalist; photo examined
EcuadorLojaLas JuntasiNaturalist; photo examined
EcuadorLojaLoja*Parker 1930
EcuadorLojaLoja, 12.2 km S ofKU 141266; VertNet
EcuadorLojaLoja, 2 km E ofSavage 1960
EcuadorLojaLoja, 3 km E ofSavage 1960
EcuadorLojaLoja, 4 km S ofMCZ 93583; VertNet
EcuadorLojaLoja, 5 km E ofCisneros-Heredia 2005
EcuadorLojaLoja, 7.6 km S ofKU 202947; VertNet
EcuadorLojaLoja, 8.5 km S ofKU 142800; VertNet
EcuadorLojaLoja, El RosalHernán Orellana, pers. comm.
EcuadorLojaRío MalacatosSalazar-Valenzuela et al. 2014
EcuadorLojaRío ZamoraMHNG 2397.032; collection database
EcuadorLojaUtuana Biological ReserveArteaga et al. 2017
EcuadorLojaVilcabambaMHNG 2397.031; collection database
EcuadorLojaYanganaTorres-Carvajal et al. 2019
EcuadorLojaZamora HuaycoPassos et al. 2013
EcuadorZamora ChinchipeEl TiroOnline multimedia
PerúPiuraBosque de ChontaPassos et al. 2013
PerúPiuraBosque de CuyasPassos et al. 2013
PerúPiuraPuente FierroPassos et al. 2013