Published February 16, 2024. Open access.

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Collared Ground Snake (Atractus collaris)

Reptiles of Ecuador | Serpentes | Colubridae | Atractus collaris

English common name: Collared Ground Snake.

Spanish common name: Tierrera collareja.

Recognition: ♂♂ 24.4 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=21.8 cm. ♀♀ 32.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=30.0 cm..1 Atractus collaris differs from other snakes in its area of distribution by having a round head similar in width to the neck, small eyes, and a unique coloration.1 The dorsal surfaces are deep reddish brown with an incomplete light nape band and four (rarely five) longitudinal dark lines and a paired series of dorsolateral dark spots (Fig. 1).13 Atractus collaris further differs from other co-occurring brownish ground snakes by having a bright orange belly.2,4 From A. gaigeae, it differs by lacking a black mid-dorsal stripe and by having fewer than 200 and 184 ventral scales in females and males, respectively (more than 200 and 184 in females and males in A. gaigeae).1,3

Figure showing variation among individuals of Atractus collaris

Figure 1: Illustration of an adult female of Atractus collaris from Yasuní National Park, Orellana province, Ecuador.

Natural history: Atractus collaris is a rarely seen semi-fossorial snake that inhabits pristine lowland rainforests,3,5 secondary forests, agricultural fields, and rural gardens.3 Collared Ground Snakes have been seen foraging on the forest floor at night or during the day,6 as well as hidden under leaf-litter or under surface debris.3 Only earthworms have been recorded as prey items in this species,7 suggesting a degree of diet specialization. These harmless and shy snakes avoid predation by virtue of their camouflage and cryptozoic habits.6 One individual was removed from the stomach of a coral snake (Micrurus obscurus).3 Hatchlings have only been recorded in September,3 which coincides with the local low-water season, but all other reproductive aspects in this species remain a mystery.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..8 Atractus collaris is listed in this category primarily because the species has a wide distribution spanning numerous protected areas.8 However, some populations, particularly those in northern Ecuador, are probably destined to disappear due to rural-urban expansion, forest fires, and the fragmentation of the Amazonian landscape.8

Distribution: Atractus collaris is widely distributed throughout the western Amazon basin in Brazil, Colombia, Ecuador (Fig. 2), and Peru.

Distribution of Atractus collaris in Ecuador

Figure 2: Distribution of Atractus collaris in Ecuador. The star corresponds to the type locality: Río Cononaco, Orellana province, 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),911 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 collaris is a Latin word meaning “collar.”12 It refers to the cream nape band.

See it in the wild: Atractus collaris is found at a rate of about once every few years throughout the northern Amazon of Ecuador. The locality having the greatest number of recent observations is Yasuní Scientific Station, where the snakes have been found by sampling forest trails at night.

Authors: Duvan ZambranoaAffiliation: Universidad del Tolima, Ibagué, Colombia. and Alejandro ArteagabAffiliation: Khamai Foundation, Quito, Ecuador.

Illustrator: Valentina Nieto Fernández

How to cite? Zambrano D, Arteaga A (2024) Collared Ground Snake (Atractus collaris). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/RXPW2528

Literature cited:

  1. Passos P, Prudente A, Ramos LO, Caicedo-Portilla JR, Lynch JD (2018) Species delimitations in the Atractus collaris complex (Serpentes: Dipsadidae). Zootaxa 4392: 491–520. DOI: 10.11646/zootaxa.4392.3.4
  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. Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
  4. Savage JM (1955) Descriptions of new colubrid snakes, genus Atractus, from Ecuador. Proceedings of the Biological Society of Washington 68: 11–20.
  5. Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
  6. Field notes, Reptiles of Ecuador book project.
  7. Cunha OR, Nascimento FP (1983) Ofídios da Amazônia. XX – As espécies de Atractus Wagler, 1828, na Amazônia oriental e Maranhão (Ophidia: Colubridae). Boletim do Museu Paraense Emílio Goeldi 123: 1–38.
  8. Cisneros-Heredia DF, Arredondo JC, Bolívar W, Castañeda MR, Yánez-Muñoz M (2019) Atractus collaris. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2019-3.RLTS.T151183543A151183647.en
  9. 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.
  10. Beekes R (2010) Etymological dictionary of Greek. Brill, Boston, 1808 pp.
  11. Duponchel P, Chevrolat L (1849) Atractus. In: d’Orbigny CD (Ed) Dictionnaire universel d’histoire naturelle. MM. Renard, Martinet et Cie., Paris, 312.
  12. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.

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

ColombiaCaquetáFlorenciaPassos et al. 2018
ColombiaCaquetáVereda CaldasiNaturalist; photo examined
ColombiaCaquetáVereda Las DeliciasCaicedo Portilla 2023
ColombiaPutumayoRío PutumayoFMNH 165558; VertNet
EcuadorMorona SantiagoCentro Shuar AmazonasPassos et al. 2018
EcuadorNapoPozo YuralpaPassos et al. 2018
EcuadorOrellanaLa Joya de los SachasPassos et al. 2018
EcuadorOrellanaPompeya Sur, 7.5 km SE ofPassos et al. 2018
EcuadorOrellanaPozo ZáparoPassos et al. 2018
EcuadorOrellanaRío Cononaco*Peracca 1897
EcuadorOrellanaRío TiputiniPassos et al. 2018
EcuadorOrellanaVía NPF–TivacunoPassos et al. 2018
EcuadorOrellanaYasuni Scientific StationPassos et al. 2018
EcuadorSucumbíosComunidad ZábaloNogueira et al. 2019
EcuadorSucumbíosPañacochaPassos et al. 2018
EcuadorSucumbíosSanta ElenaPassos et al. 2018
EcuadorSucumbíosSinguePassos et al. 2018