Palmer's Snail-Eater

Reptiles of Ecuador | Serpentes | Colubridae | Dipsas | Dipsas palmeri

English common names: Palmer's Snail-Eater.

Spanish common names: Caracolera de Palmer.

Recognition: ♂♂ 129.7 cm ♀♀ 118.7 cm. The Palmer's Snail-Eater (Dipsas palmeri) is the only snake in its area of distribution having a light brown dorsum with 32–41 brown to blackish white-edged circular blotches and no white transverse line on the snout. The most similar snake species in the area are the Ornate Snail-Eater (D. catesbyi), which differs from D. palmeri by having a loreal scale that does not contact the orbit, and the Pavonine Snail-Eater (Dipsas pavonina), which has a pattern of black “saddles” that are wider near the top of the dorsum.

Natural history: Frequent. Dipsas palmeri is a nocturnal snake that inhabits old-growth to heavily disturbed evergreen montane forests, cloudforests, forest edges, pastures, rural gardens, and houses.1,2 At night, Palmer’s Snail-Eaters move actively but slowly at ground level or on vegetation up to 3.5 m above the ground.3 During the day, snakes of this species rest coiled under the leaf-litter.3 At dusk, after warm days, individuals of D. palmeri have been seen crossing roads.3 Palmer’s Snail-Eaters are harmless to humans; they are extremely docile and never attempt to bite. If threatened, individuals may flatten their body and expand their head to simulate a triangular shape. They also produce a musky and distasteful odor.3

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Conservation: Least Concern.1 Dipsas palmeri is listed in this category following IUCN criteria4 because 31 out of the 42 known localities of occurrence for the species are within the limits of protected areas or their buffer zones. Furthermore, D. palmeri is widely distributed and is present in degraded environments, which suggests that this snake species tolerates a degree of habitat modification.1

Distribution: Dipsas palmeri is native to the eastern slopes of the Andes in Ecuador and northern Peru. In Ecuador, the species occurs over an estimated 12,892 km2 area.

Distribution of Dipsas palmeri in Ecuador

Etymology: The generic name Dipsas, which comes from the Greek word dipsa (meaning “thirst”),5 probably refers to the fact that the bite of these snakes was believed to cause intense thirst. The specific epithet palmeri honors Mervyn George Palmer (1882–1954), an English naturalist who collected the specimen upon which the original description of the species was based.6

See it in the wild: Palmer's Snail-Eaters can be seen with ~20–40% certainty at night, especially after a warm day, in forested areas throughout the species' area of distribution. Some of the best localities to find Palmer's Snail-Eaters are: Reserva San Francisco and the vicinity of Baños. The snakes may be detected by scanning low vegetation along roads and trails.


Do snails attract snakes? Yes. Snail-eating snakes follow snails visually or by tracking their scent trail.7

Do snail-eating snakes eat the shell of the snails? They don't. These snakes use specialized muscular contractions of their wedge-like head to extract snails from their shells.7

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

Photographers: Alejandro ArteagaaAffiliation: Tropical Herping (TH), Quito, Ecuador. and Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: ExSitu, Quito, Ecuador.

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

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.
  2. 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.
  3. Field notes, Reptiles of Ecuador book project.
  4. IUCN (2001) IUCN Red List categories and criteria: Version 3.1. IUCN Species Survival Commission, Gland and Cambridge, 30 pp.
  5. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
  6. Boulenger GA (1912) Descriptions of new reptiles from the Andes of South America, preserved in the British Museum. Annals and Magazine of Natural History 10: 420–424.
  7. Sheehy C (2012) Phylogenetic relationships and feeding behavior of Neotropical snail-eating snakes (Dipsadinae, Dipsadini). PhD Thesis, UT Arlington.