Published March 5, 2024. Open access.

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ZGAP Ground Snake (Atractus zgap)

Reptiles of Ecuador | Serpentes | Colubridae | Atractus zgap

English common name: ZGAP Ground Snake.

Spanish common name: Tierrera de ZGAP.

Recognition: ♀♀ 41.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=37.6 cm..1 Atractus zgap differs from other co-occurring snakes by having a round head similar in width to the neck, small eyes, and a striped pattern (Fig. 1). The dorsal surfaces are uniformly dark brown with five faint longitudinal dark lines.1 The belly is bright yellow and lacks longitudinal black lines.1 This species resembles A. ecuadorensis in both coloration and scale counts, but the latter does not occur in Napo province and is characterized by having a higher number of dorsal stripes (six or seven) and more than 40 subcaudal scales in males.1

Figure showing variation among individuals of Atractus zgap

Figure 1: Individuals of Atractus zgap from El Chaco, Napo province, Ecuador.

Natural history: Atractus zgap is a semi-fossorial snake that occurs in comparatively high densities in old-growth to heavily disturbed evergreen montane forests as well as in crops and pastures adjacent to these forests.2,3 ZGAP Ground Snakes have been found hidden under rocks, logs, in soil, or among herbaceous vegetation during the day.2,3 During warm nights, they have been seen crossing dirt roads and trails or foraging under leaf-litter in the forest floor.2,3 In captivity, individuals of A. zgap consume earthworms,3 as is the case in the wild for other ground snakes.47 These harmless and shy snakes avoid predation by virtue of their cryptic coloration.

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Conservation: Endangered Considered to be facing a high risk of extinction in the near future.. Atractus zgap is a recently described species.1 Therefore, it has not been formally evaluated by the IUCN Red List. Here, it is provisionally assigned to the EN category because the species’ extent of occurrence is estimated to be less than 500 km2 and its habitat is severely fragmented and declining in extent and quality due to deforestation. The valley of the Río Quijos formed the eastern frontier of the Incan Empire (1400–1532), suffering from intensive land-use even before European arrival.8 Today, this valley is an important cattle farming area where the majority of the native forest has been destroyed. Although A. zgap occurs in one protected area (Bosque Protector “La Cascada”) and its presence is expected in adjacent Parque Nacional Cayambe-Coca and Parque Nacional Sumaco Napo-Galeras, it has so far not been recorded in major protected areas.

Distribution: Atractus zgap is known only from five localities along the valley of the Río Quijos, Napo province, in the Amazonian slopes of the Andes in northeastern Ecuador (Fig. 2).

Distribution of Atractus zgap in Ecuador

Figure 2: Distribution of Atractus zgap in Ecuador. The star corresponds to the type locality: El Chaco, Napo 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 zgap honors the ‘Zoological Society for the Conservation of Species and Populations’ (ZGAP), a program seeking to conserve unknown but highly endangered species and their natural habitats throughout the world. The ZGAP grant program supports the fieldwork of young scientists who are eager to implement and start conservation projects in their home countries.1

See it in the wild: ZGAP Ground Snakes can be seen with almost complete certainty around the towns El Chaco and Borja, especially if the search includes turning over rocks and logs in pastures near forest border. These snakes can also be located by scanning the forest floor and leaf-litter along trails and dirt roads at night.

Acknowledgments: Special thanks to Dr. Arne Schulze for supporting the discovery of Atractus zgap through the Zoological Society for the Conservation of Species and Populations (ZGAP). AA is grateful to Diego Piñán for providing information on the natural history of this elusive species.

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

Photographer: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2024) ZGAP Ground Snake (Atractus zgap). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/OLRJ4211

Literature cited:

  1. Arteaga A, Quezada A, Vieira J, Guayasamin JM (2022) Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach. ZooKeys 1121: 175–210. DOI: 10.3897/zookeys.1121.89539
  2. Field notes, Reptiles of Ecuador book project.
  3. Diego Piñán, pers. comm.
  4. Silva Haad J (2004) Las serpientes del género Atractus Wagler, 1828 (Colubridae, Xenodontinae) en la Amazonia colombiana. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 28: 409–446.
  5. 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
  6. Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
  7. Martins M, Marques OAV, Sazima I (2008) How to be arboreal and diurnal and still stay alive: microhabitat use, time of activity, and defense in neotropical forest snakes. South American Journal of Herpetology 3: 58–67. DOI: 10.2994/1808-9798(2008)3[58:HTBAAD]2.0.CO;2
  8. Loughlin NJD, Gosling WD, Mothes P, Montoya E (2018) Ecological consequences of post-Columbian indigenous depopulation in the Andean-Amazonian corridor. Nature Ecology & Evolution 2: 1233-1236. DOI: 10.1038/s41559-018-0602-7
  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.

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

EcuadorNapoBorja, 1 km NE ofArteaga et al. 2022
EcuadorNapoBosque Protector La CascadaArteaga et al. 2022
EcuadorNapoEl Chaco*Arteaga et al. 2022
EcuadorNapoRío Quijos EcolodgeArteaga et al. 2022
EcuadorNapoSanta RosaArteaga et al. 2022