Bothriechis schlegelii

Bothriechis schlegelii BERTHOLD 1846

Common Names

Eyelash Viper (English)

Languages: English


Brief Summary

The Eyelash Viper (Bothriechis schlegelii), known as “bocaracá” in Costa Rica, is a medium-sized (maximum total length ~80 cm) arboreal and highly venomous pit viper that feeds on a variety of small vertebrates including frogs, lizards, birds, bats, rodents, and marsupials. It is found in lowland and premontane wet forests from almost sea level to 2640 m (across most of its distribution, it occurs mostly at the lower end of this range; other Bothriechis species are generally not found at low elevations). The range of the Eyelash Viper extends from Chiapas, Mexico, to northwestern Ecuador and western Venezuela. (Lomonte et al. 2008 and references therein; Sorrell 2009 and references therein)

Eyelash Vipers may be found in a range of colors, including green, brown, rust, gray, light blue, and (in Costa Rica) golden yellow. The "eyelashes" that give this snake its name are actually hoodlike scales over each eye. These snakes are responsible for a number of human fatalities each year, generally resulting from people overlooking these motionless, well camouflaged vipers when climbing trees or reaching into tree branches or clusters of fruit. (Henderson et al. 2010) The facial pits of pit vipers such as the Eyelash Viper and many others were at one time believed to be used only for locating warm-blooded prey, but these heat-sensing structures have now been shown to play an important role in facilitating behavioral thermoregulation (Krochmal et al. 2004).

Sorrell (2009) studied diel patterns of movement and predatory behavior of Eyelash Vipers in an Atlantic lowland tropical moist forest in Panama. During the day, Eyelash Vipers were most frequently found motionless in a hunting posture (i.e., with the body positioned for a strike and facing an object that could serve as a prey runway such as a branch, liana, tree bole, or tree buttress). Individuals were significantly more likely to move between perches at night than during the day. Sorrell was able to identify ten prey items representing seven taxa; five of these prey species had not previously been reported as Eyelash Viper food items. Combined with literature records, Sorrell tallied a total of 15 prey categories (mostly identified to species), seven of them mainly diurnal and eight mainly nocturnal.  He notes that the list of Eyelash Viper prey items includes frogs, indicating that this species actively forages at night because sedentary, nocturnal prey items (e.g., Eleutherodactylus frogs) are unlikely to be encountered by a snake using only ambush methods. (Lomonte et al. (2008) and references therein; Sorrell 2009 and references therein)

Castoe et. al. (2009) studied the phylogeographic and biogeographic history of New World pitvipers, focusing on three genera (Atropoides [the jumping pitvipers], Bothriechis [the palm pitvipers], and Cerrophidion [the montane pitvipers]) that are broadly co-distributed across the highlands of Middle America. According to their analyses, the extant sister species to B. schlegelii is B. supraciliaris of southwestern Costa Rica (a formerly synonymized species [Werman 1984 and references therein] restored to species rank by Solorzano et al. 1998). This supports the finding by Taggart et al. (2001).

Antonio (1980) described the courtship and copulatory behavior of a pair of captive Eyelash Vipers from Honduras, as well as some preliminary data on the genetics of coloration in this species.

Lomonte et al. (2008) characterized the venoms of B. schlegelii and B. lateralis with respect to their protein composition and investigated which protein species within these snake venoms are effectively recognized and immunoprecipitated by the polyvalent antivenom manufactured at the Instituto Clodomiro Picado (University of Costa Rica), which is made using a mixture of venoms from three different three pitvipers (B. asper, Crotalus durissus durissus, and Lachesis stenophrys).

Author(s): Shapiro, Leo
Rights holder(s): Shapiro, Leo


  • Bothriechis supraciliaris SOLORZANO 1998 (synonym)
  • Bothrops (Teleuraspis) nigroadspersus STEINDACHNER 1870 (synonym)
  • Bothrops Schlegeli JAN 1863 (synonym)
  • Bothrops schlegelii PETERS 1970 (synonym)
  • Bothrops schlegelii supraciliaris TAYLOR 1954 (synonym)
  • Bothrops schlegelli HOGE 1966 (synonym)
  • Lachesis nitidus GÜNTHER 1859 (synonym)
  • Lachesis schlegelii BOULENGER 1896 (synonym)
  • Thanatophis torvus POSADA 1889 (synonym)
  • Trigonocephalus schlegelii BERTHOLD 1846 (synonym)
  • Trimeresurus schlegelii BOCOURT 1909 (synonym)


Antonio, F. B. (1980).  Mating Behavior and Reproduction of the Eyelash Viper (Bothrops schlegeli) in Captivity. Herpetologica. 36, 231-233.
Castoe, T. A., Daza J. M., Smith E. N., Sasa M. M., Kuch U., Campbell J. A., et al. (2009).  Comparative phylogeography of pitvipers suggests a consensus of ancient Middle American highland biogeography. Journal of Biogeography. 36, 88-103.
Henderson, C. L., Adams S., & Hallwachs W. (2010).  Mammals, Amphibians, and Reptiles of Costa Rica: A Field Guide. Austin, Texas: University of Texas Press.
Krochmal, A. R., Bakken G. S., & LaDuc T. J. (2004).  Heat in evolution’s kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae). The Journal of Experimental Biology. 207, 4231-4238.
Lomonte, B., Escolano J., Fernández J., Sanz L., Angulo Y., Gutiérrez J. M., et al. (2008).  Snake Venomics and Antivenomics of the Arboreal Neotropical Pitvipers Bothriechis lateralis and Bothriechis schlegelii. Journal of Proteome Research. 7, 2445-2457.
Solorzano, A., Gomez L. D., Monge-Najera J., & Crother B. I. (1998).  Redescription and validation of Bothriechis supraciliaris (Serpentes : Viperidae). REVISTA DE BIOLOGIA TROPICAL. 46, 453-462.
Sorrell, G. G. (2009).  Diel Movement and Predation Activity Patterns of the Eyelash Palm-Pitviper (Bothriechis schlegelii). Copeia. 2009, 105-109.
Taggart, T. W., Crother B. I., & White M. E. (2001).  Palm-Pitviper (Bothriechis) Phylogeny, mtDNA, and Consilience. Cladistics. 17, 355-370.
Werman, S. D. (1984).  The Taxonomic Status of Bothrops supraciliaris Taylor. Journal of Herpetology. 18, 484-486.