Published May 12, 2018. Updated April 7, 2024. Open access.

Gallery ❯

Shrubland Snail-eating Snake (Dipsas jamespetersi)

Reptiles of Ecuador | Serpentes | Colubridae | Dipsas jamespetersi

English common name: Shrubland Snail-eating Snake.

Spanish common name: Caracolera de matorral.

Recognition: ♂♂ 76.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=60.9 cm. ♀♀ 77.1 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=50.6 cm..1,2 Dipsas jamespetersi can be identified by having a brown or grayish brown dorsum with 29–59 dark crossbands, an enlarged vertebral scale row, and presence of a preocular scale (Fig. 1).13 This species differs from both D. oligozonata and D. oreas by having a preocular scale.13 It further differs from these species by having smaller broken blotches that do not form complete bands on the anterior part of the body.13

Figure showing an adult male individual of Dipsas jamespetersi

Figure 1: Adult male of Dipsas jamespetersi from Corraleja, Azuay province, Ecuador.

Natural history: Dipsas jamespetersi is a primarily crepuscular and nocturnal snake that inhabits pristine to heavily disturbed montane shrublands and high evergreen montane forests.2,3 The species also occurs in areas having a matrix of pastures, agricultural land, and forest remnants.24 Shrubland Snail-eating Snakes are primarily terrestrial,24 but they also move actively on shrubs up to 3 m above the ground.4 During the day, they rest coiled inside bromeliads, at the base of agave plants, or under rocks and logs.4 In captivity, individuals of D. jamespetersi consumed slugs, rejecting other prey items such as tadpoles and lizards.4 In the wild, they are most common in areas where slugs are abundant.4 The mollusks are presumably immobilized by the use of toxins secreted by the mucous cells of the infralabial glands.5 Nevertheless, all snakes in the genus Dipsas are considered harmless to humans. They never attempt to bite, resorting instead to coiling into a defensive ball posture and producing a musky and distasteful odor when threatened.4,6 An individual of D. jamespetersi from Peru was recovered from the stomach of a coral snake Micrurus mertensi.2 Two gravid females from Ecuador each contained five eggs,2 which probably corresponds to the actual clutch size.

Reader support helps us keep the Reptiles of Ecuador book 100% free.

Conservation: Least Concern Believed to be safe from extinction given current circumstances..7 Dipsas jamespetersi is listed in this category primarily on the basis of species’ wide extent of occurrence and persistence in human-modified environments.7 Unfortunately, the majority (approximately 64% in Ecuador) of the habitat of D. jamespetersi has been destroyed, with the remaining forest patches being too small, fragemented, and declining in extent and quality.4 Live individuals of this species, though rarely encountered, are commonly seen dead on roads,4 which may indicate a high rate of mortality from vehicular traffic. Therefore, the Shrubland Snail-eating Snake may qualify for a threatened category in the near future if its habitat continues to be degraded.

Distribution: Dipsas jamespetersi occurs in the inter-Andean valleys and along the western slopes of Andes in southern Ecuador (Fig. 2) and northern Peru. In Peru, the species also occurs along the Amazonian slopes of the Andes. Although the area of distribution of this species in Ecuador is approximately 5,512 km2, probably no more than 2,000 km2 hold habitat where the species might occur.

Distribution of Dipsas jamespetersi in Ecuador

Figure 2: Distribution of Dipsas jamespetersi in Ecuador. The star corresponds to the type locality: Zhila, Azuay province. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The name Dipsas comes from the Greek dipsa (=thirst)8 and probably refers to the fact that the bite of these snakes was believed to cause intense thirst. The specific epithet jamespetersi honors American herpetologist James A. Peters (1922–1972), in recognition of his contributions to expanding the knowledge on Neotropical reptiles, particularly those of Ecuador.1,3

See it in the wild: Shrubland Snail-eating Snakes are recorded rarely, usually no more than once every few months at any given locality. However, there are some areas, like along the Vilcabamba–Palanda road and in the vicinity of the towns Nabón and Oña, where individuals are seen more frequently. These primarily terrestrial snakes may be spotted as they cross trails and roads in areas of highland shrubland, especially around sunset.

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

Photographer: Frank PichardobAffiliation: Tropical Herping (TH), Quito, Ecuador.

How to cite? Arteaga A (2024) Shrubland Snail-eating Snake (Dipsas jamespetersi). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/CUFU1599

Literature cited:

  1. Arteaga A, Salazar-Valenzuela D, Mebert K, Peñafiel N, Aguiar G, Sánchez-Nivicela JC, Pyron RA, Colston TJ, Cisneros-Heredia DF, Yánez-Muñoz MH, Venegas PJ, Guayasamin JM, Torres-Carvajal O (2018) Systematics of South American snail-eating snakes (Serpentes, Dipsadini), with the description of five new species from Ecuador and Peru. ZooKeys 766: 79–147. DOI: 10.3897/zookeys.766.24523
  2. Cadle JE (2007) The snake genus Sibynomorphus (Colubridae: Dipsadinae: Dipsadini) in Peru and Ecuador, with comments on the systematics of Dipsadini. Bulletin of the Museum of Comparative Zoology 158: 183–283. DOI: 10.3099/0027-4100(2007)158[183:TSGSCD]2.0.CO;2
  3. Orcés G, Almendáriz A (1989) Presencia en el Ecuador de los colúbridos del género Sibynomorphus. Revista Politécnica: 57–67.
  4. Field notes, Reptiles of Ecuador book project.
  5. De Oliveira L, Jared C, da Costa Prudente AL, Zaher H, Antoniazzi MM (2008) Oral glands in dipsadine “goo-eater” snakes: morphology and histochemistry of the infralabial glands in Atractus reticulatus, Dipsas indica, and Sibynomorphus mikanii. Toxicon 51: 898–913. DOI: 10.1016/j.toxicon.2007.12.021
  6. Cadle JE, Myers CW (2003) Systematics of snakes referred to Dipsas variegata in Panama and Western South America, with revalidation of two species and notes on defensive behaviors in the Dipsadini (Colubridae). American Museum Novitates 3409: 1–47.
  7. Cisneros-Heredia DF, Brito J, Yánez-Muñoz M (2019) Dipsas jamespetersi. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2019-3.RLTS.T48617631A48617634.en
  8. 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 Dipsas jamespetersi in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

EcuadorAzuayCaboganaJuan Carlos Sánchez, pers. comm. to AA
EcuadorAzuayCorralejaThis work; Fig. 1
EcuadorAzuayCumbeArteaga & Batista 2023
EcuadorAzuayEl TablónCadle 2007
EcuadorAzuayGirónJuan Carlos Sánchez, pers. comm. to AA
EcuadorAzuayGranja Orgánica SusudelPazmiño-Otamendi 2019
EcuadorAzuayLa PazArteaga et al. 2018
EcuadorAzuayNabónErnesto Arbeláez, pers. comm. to AA
EcuadorAzuayNarancayErnesto Arbeláez, pers. comm. to AA
EcuadorAzuayOñaAlmendáriz 1991
EcuadorAzuayPoetateArteaga et al. 2018
EcuadorAzuayPucaráMZUA.RE.0024; examined
EcuadorAzuaySan FernandoJuan Carlos Sánchez, pers. comm. to AA
EcuadorAzuaySusudeliNaturalist; photo examined
EcuadorAzuayTuriJuan Carlos Sánchez, pers. comm. to AA
EcuadorAzuayZhila*Orcés & Almedáriz 1989
EcuadorLojaGuachanamáArteaga et al. 2018
EcuadorLojaLojaArteaga et al. 2018
EcuadorLojaLoja, 0.5 km E ofArteaga et al. 2018
EcuadorLojaLoja, 10 Km E ofCadle 2007
EcuadorLojaLoja, 2 km E ofHarvey 2008
EcuadorLojaLoja, 24 km S ofArteaga et al. 2018
EcuadorLojaLoja, 5 km E ofArteaga et al. 2018
EcuadorLojaLoja, 7.3 km N ofCadle 2007
EcuadorLojaManúTorres-Carvajal et al. 2019
EcuadorLojaRumishitanaiNaturalist; photo examined
EcuadorLojaSaraguroArteaga et al. 2018
EcuadorLojaValle del CatamayoCadle 2007
EcuadorLojaVilcabambaPhoto by Michaël Moens
EcuadorLojaYangana, 1.6 km N ofReptiles of Ecuador book database
EcuadorLojaYangana, 9.6 km S ofReptiles of Ecuador book database
PeruAncashCajacayCadle 2007
PeruAncashMalvasCadle 2007
PeruCajamarcaAsunciónKU 221727; VertNet
PeruCajamarcaBosque de CachilCadle 2007
PeruCajamarcaMonteseco, 1 km NE ofCadle 2007
PeruCajamarcaParaguay, 3 km N ofCadle 2007
PeruCajamarcaSan PabloCadle 2007
PeruPiuraBosque de CuyasTorres-Carvajal et al. 2022
PeruPiuraHuancabamba, 33 km SW ofCadle 2007