Española Racer

Reptiles of Ecuador | Serpentes | Colubridae | Pseudalsophis | Pseudalsophis hoodensis

Spanish common names: Culebra de Española, serpiente corredora de Española.

Recognition: ♂♂ 76.5 cm ♀♀ 85.6 cm. Pseudalsophis hoodensis is the only snake known to occur on Española Island and the adjacent Gardner Islet. Males and females of this species are similar in size and coloration and, generally, they can not be distinguished from one another based on external appearance alone.

Natural history: Frequent. Española Racers are diurnal and terrestrial snakes that inhabit dry shrublands, dry grasslands, and deciduous forests.1,2 They are active on soil and rocks during the daytime, especially around 9:00 and 17:00.1,2 Snakes of this species are mildly venomous, which means their bite is dangerous to small prey, but not to humans.3 They are foraging predators that feed on Española Lava-Lizards (Microlophus delanonis).4 Their diet likely also includes geckos, juvenile Marine Iguanas (Amblyrhynchus cristatus), and bird eggs, although this has not been confirmed.

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Conservation: Near Threatened.5 Pseudalsophis hoodensis is listed in this category because this species is presumably not undergoing population declines or facing major immediate threats of extinction. Española Island is not populated by humans nor by exotic predators and is protected within the Galápagos National Park. However, since P. hoodensis is restricted to a small island, it is prone to be affected by random unpredictable events (like droughts and introduced species) within a short time period.

Distribution: Pseudalsophis hoodensis is endemic to an estimated 61 km2 area on Española Island and the adjacent Gardner Islet. Galápagos, Ecuador.

Distribution of Pseudalsophis hoodensis Distribution of Pseudalsophis hoodensis in and around Española Island

Etymology: The generic name Pseudalsophis, which comes from the Greek words pseudo (meaning “false”) and Alsophis (a genus of Caribbean snakes), refers to the similarity between snakes of the two genera.6 The specific epithet hoodensis refers to the locality where the species occurs,4 Española, previously known as Hood Island.

See it in the wild: Like most snakes in Galápagos, Española Racers are secretive animals, but, with some luck, they can be seen with ~30% certainty during tourism day trips to Española Island. The best time to look for the racers is during the first hours after sunrise or right before sunset.

Special thanks to Eric Osterman for symbolically adopting the Española Racer and helping bring the Reptiles of Ecuador book project to life.

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Authors: Alejandro Arteaga,aAffiliation: Tropical Herping (TH), Quito, Ecuador. Gabriela Aguiar, and Juan M GuayasaminbAffiliation: Laboratorio de Biología Evolutiva, Universidad San Francisco de Quito (USFQ), Quito, Ecuador.,cAffiliation: Galapagos Science Center, Galápagos, Ecuador.,dAffiliation: Centro de Investigación de la Biodiversidad y Cambio Climático, Universidad Tecnológica Indoamérica, Quito, Ecuador.

Academic reviewers: Robert A Thomas and Luis Ortiz-Catedral.

Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,eAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A, Aguiar G, Guayasamin JM (2020) Pseudalsophis hoodensis. In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from:

Literature cited:

  1. Field notes, Reptiles of Ecuador book project.
  2. Altamirano MA (1991) Potential influences of biotic and abiotic factors on patterns of activity in Galápagos snakes. New Mexico. MSc thesis, Albuquerque, United States, University of New Mexico.
  3. Thomas RA (1997) Galápagos terrestrial snakes: biogeography and systematics. Herpetological Natural History 5: 19–40.
  4. Van Denburgh J (1912) Expedition of the California Academy of Sciences to the Galápagos Islands, 1905-1906. IV. The snakes of the Galápagos Islands. Proceedings of the California Academy of Sciences 1: 323–374.
  5. Cisneros-Heredia DF, Márquez C (2017) Pseudalsophis hoodensis. The IUCN Red List of threatened species. Available from:
  6. Zaher H, Grazziotin FG, Cadle JE, Murphy RW, Moura-Leite JC, Bonatto SL (2009) Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines: a revised classification and descriptions of new taxa. Papéis Avulsos de Zoologia 49: 115–153.