Bothriechis schlegelii

Bothriechis schlegelii, 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. It is the most common of the green palm-pitvipers (genus Bothriechis), and is often present in zoological exhibits. The specific name schlegelii honors Hermann Schlegel, who was a German ornithologist and herpetologist. For other common names see below. No subspecies are currently recognized. The eyelash viper is a relatively small species of pitviper, with adults ranging from 55–82 cm (22–32 in) long, and females being longer and more variable in size than males, which can grow to 69 cm (27 in) long. It has a wide, triangular-shaped head, and eyes with vertical pupils. Like all pit vipers, it is solenoglyphous, having large, hypodermic needle-like fangs in the front of the upper jaw that fold back when not in use, and has heat sensitive organs, or pits, located on either side of the head between the eye and nostril. Its most distinguishing feature, and origin of its common name, is the set of 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. B. schlegelii occurs in a wide range of colors, including red, yellow, brown, green, even pink, as well as various combinations thereof. It often has black or brown speckling on the base color. No external features distinguish the two sexes. Common names of B. schlegelii include the eyelash viper, 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, and horned palm viper. In Spanish, the primary language of countries comprising its distribution, common names include bocaracá, oropel (golden morph), víbora bocaracá, toboba pestanas, víbora de pestañas (eyelash viper), and serpiente loro (parrot snake). The geographic range of B. schlegelii extends from southern Mexico (northern Chiapas), southeastward on the Atlantic plains and lowlands through Central America to northern South America in Colombia and Venezuela. It is also found on the Pacific versant and lowlands in parts of Costa Rica, Panama, Colombia, Ecuador and Peru. It occurs in mesic forest at elevations almost from sea level to 2,640 m (8,660 ft) altitude. The type locality is “Popayan” (Popayán, Colombia). B. schlegelii prefers lower altitude, humid, tropical areas with dense foliage, generally not far from a permanent water source. One study noted the preference of B. schlegelii for deep, shady ravines. Like other Bothriechis members, B. schlegelii is arboreal and has a strong prehensile tail. It is largely nocturnal, consuming small rodents, frogs, lizards and small birds. It is not known to be an aggressive snake, but will not hesitate to strike if harassed. A typical ambush predator, it waits patiently for unsuspecting prey to wander by. Sometimes, it is known to select a specific ambush site and return to it every year in time for the spring migration of birds. Studies have indicated that B. schlegeli learns to improve strike accuracy over time. Sometimes B. schlegelii (especially juveniles) will employ what is known as “caudal luring”, wiggling the tail in worm-like motions to encourage potential prey to move within striking range.