Published July 17, 2024. Updated June 30, 2025. Open access. | Purchase book ❯ |
Boursier’s Spot-lipped Snake (Saphenophis boursieri)
Reptiles of Ecuador | Serpentes | Colubridae | Saphenophis boursieri
English common names: Boursier’s Spot-lipped Snake, Spotted Genuine Snake.
Spanish common names: Culebra labio pintado de Boursier, culebra manchada de Boursier.
Recognition: ♂♂ 66.5 cm ♀♀ 77.9 cm.1–4 Saphenophis boursieri is a small brown snake that can be identified by having black-spotted enamel white lips, with the spots sometimes coalescing into a sinuous line.1–4 The dorsum is rich yellowish brown with a black ocular-lateral stripe (Fig. 1).1–4 The ventral surfaces are bright golden yellow with black pigment on the anterior border of each scale. This species can be found living alongside Erythrolamprus albiventris, a predominantly green snake that has immaculate throat and lips.3
Figure 1: Juveniles of Saphenophis boursieri from Arlequín Reserve, Pichincha province, Ecuador.
Natural history: Saphenophis boursieri is a rarely seen terrestrial snake that occurs naturally in semi-open areas and clearings within old-growth cloud forests and high evergreen montane forests.3–5 The species also occurs in pastures and along roadsides.3 Boursier’s Spot-lipped Snakes are typically active at ground level during overcast and drizzly days,5 but individuals have also been seen active during sunny days.3,4 Their foraging occurs on leaf-litter, grass, bare soil, or gravel along dirt roads.3–5 The diet of this species consists primarily of amphibians,5 but also includes lizards of the genus Riama and insect larvae.4 The typical defense behavior in this harmless snake consists of musking while exposing the bright yellow tail underside.5 Three gravid females contained 5–7 eggs,4 which probably corresponds to the actual clutch size.
Conservation: Near Threatened .6 Saphenophis boursieri is listed in this category because, at the time of the assessment in 2013, the species was believed to have a wide distribution in Colombia, Ecuador, and presumably even Perú. However, the actual extent of occurrence of S. boursieri is probably no greater than 3,000 km2, with records outside Ecuador corresponding to different species. Although small, the area where the species occurs in Ecuador is comparatively well-preserved, with approximately 72% of the forest cover still intact. The species has been recorded in 14 privately protected areas.
Distribution: Saphenophis boursieri is endemic to an area of approximately 2,582 km2 along the western slopes of the Andes in northern Ecuador (Fig. 2).
Figure 2: Distribution of Saphenophis boursieri in Ecuador. The star corresponds to the approximate type locality near Quito, Pichincha province. See Appendix 1 for a complete list of the presence localities included in the map.
Etymology: The genus name Saphenophis comes from the Greek words saphenes (=evident) and ophis (=snake).7 The species is named in honor of Mr. Boursier de La Rivière, a French explorer who is thought to have collected the holotype.3
See it in the wild: Boursier’s Spot-lipped Snakes are recorded at a rate of about once a month along the old Nono–Mindo road, especially during drizzly days.
Special thanks to John Sullivan for symbolically adopting the Boursier’s Spot-lipped Snake and helping bring the Reptiles of Ecuador book project to life.
Click here to adopt a species.
Author: Alejandro Arteagaa
Photographer: Amanda Quezadaa
How to cite? Arteaga A (2025) Boursier’s Spot-lipped Snake (Saphenophis boursieri). 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/OQSQ9559
Literature cited:
- Myers CW (1973) A new genus for Andean snakes related to Lygophis boursieri and a new species (Colubridae). American Museum Novitates 2522: 1–37.
- Myers CW (1969) South American snakes related to Lygophis boursieri: A reappraisal of Rhadinaea antioquiensis, Rhadinaea tristriata, Coronella whymperi, and Liophis atahuallpae. American Museum Novitates 2385: 1–27.
- Arteaga A, Bustamante L, Guayasamin JM (2013) The amphibians and reptiles of Mindo. Universidad Tecnológica Indoamérica, Quito, 257 pp.
- Cisneros-Heredia DF (2005) Saphenophis boursieri. Habitat, reproduction and diet. Herpetological Review 36: 71.
- Field notes, Reptiles of Ecuador book project.
- Cisneros-Heredia DF, Bolívar W, Velasco J, Arredondo JC (2017) Saphenophis boursieri. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2017-2.RLTS.T44581808A44581817.en
- 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 Saphenophis boursieri in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Ecuador | Cotopaxi | Las Pampas | Arteaga et al. 2013 |
| Ecuador | Imbabura | Junín, 4 km NE of | iNaturalist; photo examined |
| Ecuador | Imbabura | Neblina Bird Lodge | iNaturalist; photo examined |
| Ecuador | Imbabura | Reserva Siempre Verde | Arteaga et al. 2013 |
| Ecuador | Imbabura | San Antonio | Cisneros-Heredia 2005 |
| Ecuador | Pichincha | Alaspungo | Valencia et al. 2017 |
| Ecuador | Pichincha | Bellavista Lodge | Arteaga et al. 2013 |
| Ecuador | Pichincha | Bosque La Victoria | Yánez-Muñoz et al. 2009 |
| Ecuador | Pichincha | Chespi | iNaturalist; photo examined |
| Ecuador | Pichincha | Choco Birds Reserve | iNaturalist; photo examined |
| Ecuador | Pichincha | Cordillera del Saloya | Yánez-Muñoz et al. 2009 |
| Ecuador | Pichincha | El Cedral | Arteaga et al. 2013 |
| Ecuador | Pichincha | Guantopungo–Yunguilla | Valencia et al. 2017 |
| Ecuador | Pichincha | Guarumos–Nono | iNaturalist; photo examined |
| Ecuador | Pichincha | Hacienda Las Palmas | Yánez-Muñoz et al. 2009 |
| Ecuador | Pichincha | La Unión–Río Cinto | Yánez-Muñoz et al. 2009 |
| Ecuador | Pichincha | Llambo | Arteaga et al. 2013 |
| Ecuador | Pichincha | Nono–Nanegalito, km 5 | Valencia et al. 2017 |
| Ecuador | Pichincha | Quebrada frutillas | iNaturalist; photo examined |
| Ecuador | Pichincha | Reserva Arlequín | This work; Fig. 1 |
| Ecuador | Pichincha | Reserva Oreothraupis | iNaturalist; photo examined |
| Ecuador | Pichincha | Reserva Orquideológica Pahuma | Arteaga et al. 2013 |
| Ecuador | Pichincha | Santa Lucía Cloud Forest Reserve | Savit 2006 |
| Ecuador | Pichincha | Santa Lucía Reserve, 3 km NE of | Arteaga et al. 2013 |
| Ecuador | Pichincha | Tambo Tanda Lodge | Arteaga et al. 2013 |
| Ecuador | Pichincha | Tambo Tanda lodge, 1 km E of | iNaturalist; photo examined |
| Ecuador | Pichincha | Tamboquinde | Yánez-Muñoz et al. 2009 |
| Ecuador | Pichincha | Tandayapa, 3.5 km SW of | iNaturalist; photo examined |
| Ecuador | Santo Domingo de los Tsáchilas | Bosque Protector Río Guajalito | Cisneros-Heredia 2005 |
| Ecuador | Santo Domingo de los Tsáchilas | La Favorita | Arteaga et al. 2013 |
| Ecuador | Santo Domingo de los Tsáchilas | Las Palmeras | Arteaga et al. 2013 |
| Ecuador | Santo Domingo de los Tsáchilas | Miligali | Myers 1973 |