Eyelash pit viper, Eyelash palm viper, Eyelash palm-pitviper, Schlegel's viper, Schlegel's pit viper, Schlegel's palm viper, Eyelash snake, Eyelash lancehead, Eyelash mountain viper, Horned palm viper. In Spanish: Bocaracá, Oropel (golden morph), Víbora b
The Eyelash viper is a venomous pit viper species found in Central and South America. Small and arboreal, this species is characterized by a wide array of color variations, as well as the superciliary scales above the eyes. Eyelash vipers have a wide, triangular-shaped head, and eyes with vertical pupils. Like all pit vipers, they have large, hypodermic needle-like fangs in the front of the upper jaw that fold back when not in use, and have heat-sensitive organs, or pits, located on either side of the head between the eye and nostril. The most distinguishing feature of Eyelash vipers and origin of their common name are modified scales above the eyes that look much like eyelashes. The eyelashes are thought to aid in camouflage, breaking up the snake's outline among the foliage where it hides. These snakes have a wide range of colors, including red, yellow, brown, green, even pink, as well as various combinations thereof. They often have black or brown speckling on the base color.
The geographic range of Eyelash vipers extends from southern Mexico (northern Chiapas), southeastward on the Atlantic plains and lowlands through Central America to northern South America in Colombia and Venezuela. They are also found on the Pacific versant and lowlands in parts of Costa Rica, Panama, Colombia, Ecuador, and Peru. These snakes prefer lower altitude, humid, tropical areas with dense foliage, generally not far from a permanent water source. They may also occur in deep, shady ravines and plantations.
Eyelash vipers are solitary and nocturnal creatures. They are arboreal and like to stay in dense vegetation. Typical ambush predators, when hunting they wait patiently for unsuspecting prey to wander by. Sometimes, Eyelash vipers may select a specific ambush site and return to it every year in time for the spring migration of birds. Sometimes these snakes (especially juveniles) perform what is known as “caudal luring”, wiggling the tail in worm-like motions to encourage potential prey to move within striking range. There is a myth among villagers in some small areas of South America that the Eyelash viper will wink, flashing its "eyelashes" at its victim, following a venomous strike. In fact, snakes are not physiologically capable of such behavior, as they have no eyelids and can not close their eyes. Eyelash vipers are not aggressive by their nature, but if threatened will not hesitate to strike.
Eyelash vipers are polygynous meaning that one male mates with more than one female. During the mating season, males engage in a sometimes hours-long courtship ritual called a "dance of the adders", in which two males posture and intimidate one another in an upright, "cobra-like" stance until one is pushed away or falls to the ground. They are ovoviviparous and reproduce throughout the year in warm environments. Females carry eggs for around 6 months before they hatch internally, where the young complete their development. Pregnant females have enlarged lower abdomens and may stop eating in the later stages of pregnancy. In a typical brood, they give birth to 2-20 live young, which are 15-20 cm (5.9-7.9 in) in length and appear physically similar to adults. The snakelets are independent on the first day of their life and reach reproductive maturity at around two years of age.
Eyelash vipers are not listed as threatened, however, they could be at risk of habitat loss from increased deforestation for timber, agriculture, and urbanization.
According to IUCN, the Eyelash viper is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Eyelash vipers play an important role in their ecosystem as they help to control populations of small vertebrate animals.