Published May 12, 2018. Updated April 9, 2024. Open access. | Purchase book ❯ |
Mountain Snail-eating Snake (Dipsas oreas)
Reptiles of Ecuador | Serpentes | Colubridae | Dipsas oreas
English common name: Mountain Snail-eating Snake.
Spanish common name: Caracolera montañera.
Recognition: ♂♂ 78.5 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=54.3 cm. ♀♀ 82.7 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=62.6 cm..1 Dipsas oreas can be identified by lacking a preocular scale and by having a grayish or brownish dorsum with 17–30 dark oval to elliptical dorsolateral blotches that form complete bands on the anterior part of the body (Fig. 1).1,2 This species differs from D. andiana by having blotches that form complete bands on the anterior part of the body and by lacking a clearly defined dark ∩-shaped mark on the back of the head.1,3 From D. jamespetersi and D. oligozonata, it differs by having oval or elliptical blotches instead of dorsal crossbands.4
Figure 1: Individuals of Dipsas oreas from Corraleja () and Girón (), Azuay province, Ecuador.
Natural history: Dipsas oreas is a nocturnal snake that inhabits montane shrublands, montane forests, and cloud forests, occurring also in crops and in pastures with scattered trees.1,5 Mountain Snail-Eaters are active at night, especially during the rainy season (December–May) or whenever it is raining or drizzling,1,5 with most activity occurring at ground level or on low (0.15–2.3 m) vegetation.1,5,6 The increased foraging during humid periods is probably related to their diet, which consists of slugs and snails.1,5 During the day, these snakes have been found coiled under rocks, beneath leaf-litter, or in crevices and bromeliads.1,5 The Mountain Snail-Eater, when threatened, typically responds by musking, flattening the body, coiling into a defensive posture, and expanding the head to simulate a triangular shape.1,5 Aggregations of seven individuals of D. oreas (one female and six males), presumably related to mating, have been reported.1,5 Females lay clutches of 3–8 eggs in communal nesting sites such as in crevices 5–30 cm underground.5,7
Conservation: Near Threatened Not currently at risk of extinction, but requires some level of management to maintain healthy populations..8 Dipsas oreas is listed in this category because the majority of the species’ natural habitat is fragmented and continues to decline in extent and quality due to the expansion of the agricultural frontier.6,8 In Ecuador, approximately 64% of the habitat of this species has been destroyed.9 The patches of shrubland vegetation where Mountain Snail-Eaters occur are too few, heavily disturbed, and lack connectivity between them.6,8 Individuals of D. oreas are commonly seen dead on roads, which may indicate a high rate of mortality from vehicular traffic.5 Therefore, the species could qualify for a threatened category in the near future if its habitat continues to be degraded.
Distribution: Dipsas oreas is native to the inter-Andean valleys and both slopes of the Andes in southern Ecuador (Fig. 2) and northern Peru. Although the area of distribution of D. oreas in Ecuador is approximately 21,246 km2 probably only about 7,660 km2 holds habitat where the species might persist.
Figure 2: Distribution of Dipsas oreas in Ecuador. 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)10 and probably refers to the fact that the bite of these snakes was believed to cause intense thirst. The specific epithet oreas comes from the Greek word oros (=mountain)10 and refers to the distribution of the species.
See it in the wild: Mountain Snail-eating Snakes can be seen at a rate of about once every few nights, especially during the rainy season in western Ecuador (Dec–May). Prime localities for the species include the valleys of Girón and Vilcabamba.
Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.
Photographer: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador.
How to cite? Arteaga A (2024) Mountain Snail-eating Snake (Dipsas oreas). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/OMHJ8000
Literature cited:
- Cadle JE (2005) Systematics of snakes in the Dipsas oreas complex (Colubridae: Dipsadinae) in western Ecuador and Peru, with revalidation of D. elegans (Boulenger) and D. ellipsifera (Boulenger). Bulletin of the Museum of Comparative Zoology 158: 67–136.
- 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
- 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.
- 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
- Field notes, Reptiles of Ecuador book project.
- Almendáriz A (2007) Primer registro de Dipsas oreas en la provincia del Azuay, Ecuador. Revista Politécnica 27: 136–137.
- Cadle JE, Chuna P (1995) A new lizard of the genus Macropholidus (Teiidae) from a relictual humid forest of northwestern Peru, and notes on Macropholidus ruthveni Noble. Breviora 501: 1–39.
- Yánez-Muñoz M, Venegas P, Cisneros-Heredia DF (2017) Dipsas oreas. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2017-2.RLTS.T50951300A50951309.en
- MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
- 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 oreas in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Ecuador | Azuay | Chorros de Girón | Reptiles of Ecuador book database |
| Ecuador | Azuay | Corraleja | This work; Fig. 1 |
| Ecuador | Azuay | Cuenca | Ernesto Arbeláez, pers. comm. |
| Ecuador | Azuay | Cumbe | Arteaga et al. 2018 |
| Ecuador | Azuay | Flor y Selva | MZUA.RE.0119; examined |
| Ecuador | Azuay | Girón | This work; Fig. 1 |
| Ecuador | Azuay | Luz María | Arteaga et al. 2018 |
| Ecuador | Azuay | Molleturo | Ernesto Arbeláez, pers. comm. |
| Ecuador | Azuay | Norambote | Reptiles of Ecuador book database |
| Ecuador | Azuay | Reserva Biológica Yunguilla | Arteaga et al. 2018 |
| Ecuador | Azuay | San Rafael de Sharug | Arteaga et al. 2018 |
| Ecuador | Azuay | Trincheras de Ernesto | Almedáriz 2007 |
| Ecuador | Azuay | Turupamba | Ernesto Arbeláez, pers. comm. |
| Ecuador | Chimborazo | Alausí | Despax 1911 |
| Ecuador | Chimborazo | Huigra | Cadle & Myers 2003 |
| Ecuador | Chimborazo | Multitud | Arteaga et al. 2018 |
| Ecuador | Chimborazo | Pallatanga | Orton 1867 |
| Ecuador | Chimborazo | Valle del Chanchán | Cadle & Myers 2003 |
| Ecuador | El Oro | Lote Reiniero | Reptiles of Ecuador book database |
| Ecuador | El Oro | Playa Limón | Arteaga et al. 2018 |
| Ecuador | El Oro | Remolino | Garzón-Santomaro et al. 2019 |
| Ecuador | El Oro | Reserva Biológica Buenaventura | Arteaga et al. 2018 |
| Ecuador | El Oro | Zaruma | Online multimedia |
| Ecuador | Loja | Amaluza | iNaturalist; photo examined |
| Ecuador | Loja | Catacocha, 20 Km NE of | Cadle & Myers 2003 |
| Ecuador | Loja | Catamayo | Almendáriz 2007 |
| Ecuador | Loja | Cazerío Balzones | Arteaga et al. 2018 |
| Ecuador | Loja | Guacarrumi | iNaturalist; photo examined |
| Ecuador | Loja | Jimbura | Arteaga et al. 2018 |
| Ecuador | Loja | Jorupe | Reptiles of Ecuador book database |
| Ecuador | Loja | Loja | Photo by Felix Fleck |
| Ecuador | Loja | Masanamaca | Arteaga et al. 2018 |
| Ecuador | Loja | Quilanga | iNaturalist; photo examined |
| Ecuador | Loja | Río Catamayo | Cadle 2005 |
| Ecuador | Loja | Rumi Wilco | iNaturalist; photo examined |
| Ecuador | Loja | San Antonio, 1 km W of | iNaturalist; photo examined |
| Ecuador | Loja | San Pedro, 33 km E of | Arteaga et al. 2018 |
| Ecuador | Loja | Saraque, 1.7 km SE of | iNaturalist; photo examined |
| Ecuador | Loja | Velacruz | Cadle 2005 |
| Ecuador | Loja | Vía al Cerro Toledo | Arteaga et al. 2018 |
| Ecuador | Loja | Vilcabamba | Arteaga et al. 2018 |
| Ecuador | Zamora Chinchipe | San Andrés | Torres-Carvajal et al. 2019 |
| Perú | Cajamarca | Río Zaña study site | Cadle 2005 |
| Perú | Lambayeque | Limón, 6 km S of | iNaturalist; photo examined |
| Perú | Piura | Ayabaca | Cadle 2005 |
| Perú | Piura | Canchaque, 15 km E of | Cadle 2005 |
| Perú | Piura | Cerro Aypate | Cadle 2005 |
| Perú | Piura | Porculla, 2 km W of | Cadle 2005 |
| Perú | Piura | Toronche | Cadle 2005 |