Published June 20, 2020. Updated February 26, 2024. Open access.

Gallery ❯

Greater Ground Snake (Atractus major)

Reptiles of Ecuador | Serpentes | Colubridae | Atractus major

English common names: Greater Ground Snake, Big Ground Snake.

Spanish common name: Tierrera grande, culebra tierrera mayor.

Recognition: ♂♂ 53.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=51.2 cm. ♀♀ 98.6 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=85.2 cm..1,2 Atractus major can be recognized by its large size, small eyes, and dorsal pattern consisting of 21–52 pale-edged dark blotches or bands on a pale brown background color (Fig. 1).14 Most individuals have a short dark stripe on the neck.4,5 In Ecuadorian Amazonia, the most similar species are A. pachacamac and A. arangoi, both of which lack a dark mid-dorsal stripe on the neck.4 Atractus atlas occurs above the known distribution of A. major and also lacks a dark mid-dorsal stripe on the neck.6

Figure showing variation among individuals of Atractus major

Figure 1: Individuals of Atractus major: Huella Verde lodge, Pastaza province, Ecuador (); Jatun Sacha Biological Reserve, Napo province, Ecuador (); Palmarí, Amazonas state, Brazil (). j=juvenile.

Natural history: Atractus major is a semi-fossorial snake that inhabits primary and secondary rainforests,7 forest clearings,3 crops,8 and rural areas.9 Greater Ground Snakes are primarily nocturnal,5,711 although diurnal activity has also been recorded.5,12,13 They may be observed active on the ground, in leaf-litter,3 concealed beneath rocks, logs,3,7,10 and even climbing on low vegetation.7,8 Atractus major feeds primarily on giant earthworms3,6,7,13 and occasionally on insects,7,14 which are actively searched for and then captured and swallowed whole.5 Defensive behaviors include flattening the body, hiding the head under body coils,7 and poking with the tail.10 The only known predators of this species are coralsnakes (Micrurus surinamensis and Micrurus obscurus).10,15 In some parts the Amazon, hatching in A. major coincides with periods of low rainfall.7 Females containing 3–12 eggs have been found,16 but the real clutch size is unknown.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..17 Atractus major is listed in this category because the species has a large distribution, uses a wide range of habitat types, occurs in protected areas, and lacks major immediate extinction threats.17 The impact of human activities on ecuadorian populations of A. major is not clear, however, there are records of traffic mortality.18

Distribution: Atractus major is native to an area of approximately 403,448 km2 throughout the Amazon basin and adjacent foothills of the Andes in Bolivia, Brazil, Colombia, Ecuador (Fig. 2), Peru, and Venezuela.19

Distribution of Atractus major in Ecuador

Figure 2: Distribution of Atractus major in Ecuador. The star corresponds to the type locality: Canelos, 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),2022 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 major is a Latin word meaning “greater.” It probably refers to the comparatively large body size of this species.

See it in the wild: Atractus major is found at a rate of about once every few weeks throughout the Amazon of Ecuador. Some of the best localities to find snakes of this species are: Yasuní Scientific Station, Tiputini Biodiversity Station, Jatun Sacha Biological Reserve, and Tamandúa Ecological Reserve. The snakes are most easily located by scanning the forest floor and leaf-litter along trails at night.

Authors: Duvan ZambranoaAffiliation: Universidad del Tolima, Ibagué, Colombia. and Alejandro ArteagabAffiliation: Tropical Herping (TH), Quito, Ecuador.

Photographers: Jose Vieira,cAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador., Frank Pichardo,cAffiliation: Tropical Herping (TH), Quito, Ecuador. and Sebastián Di DoménicoeAffiliation: Keeping Nature, Bogotá, Colombia.

How to cite? Zambrano D, Arteaga A (2024) Greater Ground Snake (Atractus major). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/XPYM6795

Literature cited:

  1. Boulenger G (1894) Catalogue of the snakes in the British Museum. Taylor & Francis, London, 382 pp. DOI: 10.5962/bhl.title.8316
  2. Savage JM (1960) A revision of the Ecuadorian snakes of the colubrid genus Atractus. Miscellaneous Publications, Museum of Zoology, University of Michigan 112: 1–86.
  3. Duellman WE (1978) The biology of an equatorial herpetofauna in Amazonian Ecuador. Publications of the Museum of Natural History, University of Kansas 65: 1–352.
  4. Schargel WE, Lamar WW, Passos P, Valencia JH, Cisneros-Heredia DF, Campbell JA (2013) A new giant Atractus (Serpentes: Dipsadidae) from Ecuador, with notes on some other large Amazonian congeners. Zootaxa 3721: 455–474. DOI: 10.11646/zootaxa.3721.5.2
  5. Duellman WE (2005) Cusco amazónico: the lives of amphibians and reptiles in an Amazonian rainforest. Cornell University Press, Ithaca, 433 pp.
  6. Passos P, Scanferla A, Melo-Sampaio PR, Brito J, Almendariz A (2018) A giant on the ground: another large-bodied Atractus (Serpentes: Dipsadinae) from Ecuadorian Andes, with comments on the dietary specializations of the goo-eaters snakes. Anais da Academia Brasileira de Ciências 91: e20170976. DOI: 10.1590/0001-3765201820170976
  7. Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
  8. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  9. Silva Haad JJ (2004) Las serpientes del género Atractus Wagler, 1828 (Colubridae, Xenodontinae) en la Amazonía colombiana. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 28: 1–446.
  10. Field notes, Reptiles of Ecuador book project.
  11. Natera-Mumaw M, Esqueda-González LF, Castelaín-Fernández M (2015) Atlas serpientes de Venezuela. Dimacofi Negocios Avanzados S.A., Santiago de Chile, 456 pp.
  12. Duellman WE, Salas AW (1991) Annotated checklist of the amphibians and reptiles of Cuzco Amazónico, Peru. Occasional Papers of the Museum of Natural History, the University of Kansas 143: 1–13.
  13. dos Santos-Costa MC, Maschio GF, Prudente AL (2015) Natural history of snakes from Floresta Nacional de Caxiuanã, eastern Amazonia, Brazil. Herpetology Notes 8: 69–98.
  14. Martins M, Oliveira ME (1993) The snakes of the genus Atractus Wagler (Reptilia: Squamata: Colubridae) from the Manaus region, central Amazonia, Brazil. Zoologische Mededelingen 67: 21–40.
  15. Field notes of Marcos Scarello.
  16. Esqueda LF, La Marca E (2005) Revisión taxonómica y biogeográfica (con descripción de 5 nuevas especies) del genero Atractus (Colubridae: Dipsadinae) en los Andes de Venezuela. Herpetotropicos 2: 1–32.
  17. Nogueira C, Cisneros-Heredia DF, Catenazzi A, Gonzales L, Schargel W, Rivas G (2016) Atractus major. The IUCN Red List of threatened species. Available from:
  18. Filius J, van der Hoek Y, Jarrín‐V P, van Hooft P (2020) Wildlife roadkill patterns in a fragmented landscape of the Western Amazon. Ecology and Evolution 10: 6623–6635. 10.1002/ece3.6394
  19. Nogueira CC, Argôlo AJS, Arzamendia V, Azevedo JA, Barbo FE, Bérnils RS, Bolochio BE, Borges-Martins M, Brasil-Godinho M, Braz H, Buononato MA, Cisneros-Heredia DF, Colli GR, Costa HC, Franco FL, Giraudo A, Gonzalez RC, Guedes T, Hoogmoed MS, Marques OAV, Montingelli GG, Passos P, Prudente ALC, Rivas GA, Sanchez PM, Serrano FC, Silva NJ, Strüssmann C, Vieira-Alencar JPS, Zaher H, Sawaya RJ, Martins M (2019) Atlas of Brazilian snakes: verified point-locality maps to mitigate the Wallacean shortfall in a megadiverse snake fauna. South American Journal of Herpetology 14: 1–274. DOI: 10.2994/SAJH-D-19-00120.1
  20. 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.
  21. Beekes R (2010) Etymological dictionary of Greek. Brill, Boston, 1808 pp.
  22. 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 major in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

ColombiaCaquetáEstación de Campo MacagualCalderón et al. 2023
ColombiaPutumayoMansoyáGeopark Colombia 2022
ColombiaPutumayoMocoaPassos & Fernandes 2008
ColombiaPutumayoPuerto CaicedoPassos & Fernandes 2008
ColombiaPutumayoRío PutumayoGrant et al. 2023
ColombiaPutumayoVereda Islas de CartagenaBorja-Acosta & Galeano 2024
EcuadorMorona SantiagoBosque Protector AbanicoLozano & Medranda 2008
EcuadorMorona SantiagoCentro Shuar KiimSchargel et al. 2013
EcuadorMorona SantiagoChiguazaUSNM 232690; VertNet
EcuadorMorona SantiagoFinca El PiuraiNaturalist; photo examined
EcuadorMorona SantiagoGualaquizaSavage 1960
EcuadorMorona SantiagoMacasPassos & Fernandes 2008
EcuadorMorona SantiagoMacas–Riobamba roadArteaga et al. 2022
EcuadorMorona SantiagoMacumaSchargel et al. 2013
EcuadorMorona SantiagoMéndez, environs ofUSNM 232692; VertNet
EcuadorMorona SantiagoPaantimSchargel et al. 2013
EcuadorMorona SantiagoRío AbanicoReptiles of Ecuador book database
EcuadorMorona SantiagoRío SantiagoiNaturalist; photo examined
EcuadorMorona SantiagoSan Pedro de ChumpiasiNaturalist; photo examined
EcuadorMorona SantiagoTaishaPhoto by Axel Marchelie
EcuadorMorona SantiagoTurulaAMNH 35966; examined
EcuadorMorona SantiagoVilla AshuaraOrtega-Andrade 2010
EcuadorNapoAlto SindiSchargel et al. 2013
EcuadorNapoComunidad GarenoArteaga et al. 2022
EcuadorNapoHuataracoUSNM 232653; VertNet
EcuadorNapoJatun Sacha Biological ReserveArteaga et al. 2022
EcuadorNapoLago AgrioSchargel et al. 2013
EcuadorNapoPacto Sumaco, 3 km S ofCamper et al. 2021
EcuadorNapoRío CotopinoSchargel et al. 2013
EcuadorNapoRío PucunoUSNM 232650; VertNet
EcuadorNapoRío SunoUSNM 232658; VertNet
EcuadorNapoShushufindi, Río AguaricoUSNM 232660; VertNet
EcuadorNapoSinchi SachaPhoto by Ernesto Arbeláez
EcuadorNapoTena, av. MuyunaReptiles of Ecuador book database
EcuadorNapoWild Sumaco Wildlife SanctuaryCamper et al. 2021
EcuadorNapoYachana ReserveWhitworth & Beirne 2011
EcuadorNapoZoo el ArcaPhoto by Diego Piñán
EcuadorOrellanaBoca del Río CocaPassos et al. 2007
EcuadorOrellanaKupi, 5 km NE ofiNaturalist; photo examined
EcuadorOrellanaLoretoUSNM 232656; VertNet
EcuadorOrellanaNapo Wildlife CenterReptiles of Ecuador book database
EcuadorOrellanaNenkeparePhoto by Etienne Littlefair
EcuadorOrellanaNPFReptiles of Ecuador book database
EcuadorOrellanaNPF, 5 km N ofSchargel et al. 2013
EcuadorOrellanaReserva Río BigalGarcía et al. 2021
EcuadorOrellanaSan José de PayaminoMaynard et al. 2016
EcuadorOrellanaShiripuno LodgeReptiles of Ecuador book database
EcuadorOrellanaTambocochaArteaga et al. 2022
EcuadorOrellanaTiguinoPassos et al. 2007
EcuadorOrellanaTiputini Biodiversity Station Cisneros-Heredia 2003
EcuadorOrellanaVía Pompeya Sur–IroArteaga et al. 2022
EcuadorOrellanaYarentaroArteaga et al. 2022
EcuadorOrellanaYasuni Scientific StationArteaga et al. 2017
EcuadorOrellanaYuturiiNaturalist; photo examined
EcuadorPastaza5 km S de Campo Yuralpa, Plataforma WaponiTorres-Carvajal et al. 2019
EcuadorPastazaAlto CurarayUSNM 232671; VertNet
EcuadorPastazaArajunoUSNM 232670; VertNet
EcuadorPastazaArutam Field StationSMF; VertNet
EcuadorPastazaBetwen Puyo and MacasSchargel et al. 2013
EcuadorPastazaCabeceras del BobonazaUSNM 232680; VertNet
EcuadorPastazaCampo K10Schargel et al. 2013
EcuadorPastazaCanelos*Boulenger 1894
EcuadorPastazaCharapacochaSchargel et al. 2013
EcuadorPastazaChichirotaUSNM 232674; VertNet
EcuadorPastazaCopatazaUSNM 232666; VertNet
EcuadorPastazaCurarayPassos & Fernandes 2008
EcuadorPastazaGuacheNogueira et al. 2019
EcuadorPastazaHacienda San FranciscoSavage 1961
EcuadorPastazaHuella Verde LodgeThis work; Fig. 1
EcuadorPastazaJuyuintzaOrtega-Andrade 2010
EcuadorPastazaKapawi LodgeiNaturalist; photo examined
EcuadorPastazaLorocachiArteaga et al. 2022
EcuadorPastazaManderoyacuPassos et al. 2007
EcuadorPastazaMeraSchargel et al. 2013
EcuadorPastazaRío BufeoOrtega-Andrade 2010
EcuadorPastazaRío CorrientesUSNM 232672; VertNet
EcuadorPastazaRío LliquinoUSNM 232667; VertNet
EcuadorPastazaRío SarayakilloArteaga et al. 2022
EcuadorPastazaRío TalinUSNM 232675; VertNet
EcuadorPastazaRío TigreNogueira et al. 2019
EcuadorPastazaRío VillanoUSNM 232676; VertNet
EcuadorPastazaSarayacuSavage 1960
EcuadorPastazaSumak Kawsay In SituBentley et al. 2021
EcuadorPastazaTamandúa ReserveReptiles of Ecuador book database
EcuadorPastazaTarangaroNogueira et al. 2019
EcuadorPastazaUNOCAL Base CampSchargel et al. 2013
EcuadorPastazaVillano BSchargel et al. 2013
EcuadorSucumbíosBocana Río CuyabenoPassos et al. 2007
EcuadorSucumbíosDuvunoPassos et al. 2007
EcuadorSucumbíosEl ReventadorMHNG 2250.033; collection database
EcuadorSucumbíosGarzacochaYánez-Muñoz & Venegas 2008
EcuadorSucumbíosGonzalo PizarroPhoto by John Castillo
EcuadorSucumbíosLumbaquiMCZ 166523; VertNet
EcuadorSucumbíosLumbaqui, parroquia urbanaDueñas and Báez 2021
EcuadorSucumbíosPañachocaSchargel et al. 2013
EcuadorSucumbíosRío San MiguelReptiles of Ecuador book database
EcuadorSucumbíosSani LodgeiNaturalist; photo examined
EcuadorSucumbíosSanta CeciliaSchargel et al. 2013
EcuadorSucumbíosSanta ElenaiNaturalist; photo examined
EcuadorSucumbíosTerritorio Cofán DurenoYánez-Muñoz & Chimbo 2007
EcuadorZamora ChinchipeAlto MachinazaAlmendáriz et al. 2014
EcuadorZamora ChinchipeBombuscaroMejía Guerrero 2018
EcuadorZamora ChinchipeCabañas YakuamArteaga et al. 2017
EcuadorZamora ChinchipeCopalinga LodgePhoto by Aaron Hulsey
EcuadorZamora ChinchipeEl PanguiNogueira et al. 2019
EcuadorZamora ChinchipeParque Nacional PodocarpusDarwin Núñez
EcuadorZamora ChinchipeReserva Natural MaycuArteaga et al. 2017
EcuadorZamora ChinchipeValle del QuimiBetancourt et al. 2018
EcuadorZamora ChinchipeZamoraSchargel et al. 2013
PeruAmazonasPaagatUSNM 316576; VertNet
PeruLoretoCampo Santa ClaraUSNM 127120; VertNet
PeruLoretoCentro UniónDixon & Soini 1986
PeruLoretoMishanaPassos et al. 2012
PeruLoretoZona Reservada GüeppiiNaturalist; photo examined