Photo by Marceau Ratard, Costa Rica.
Eyelash vipers are in many ways one of our neatest Neotropical vipers. They have different color phases (dominated by brown or green) in Costa Rica, and the juveniles are yellow with reduced or no pattern. In Belize, where they are rarely encountered, presumably due to the higher, much less accessible elevations they prefer, they may only have the pattern and colors shown in the specimens shown above from that country. Yellow juveniles have not been observed.
Eyelash vipers are our most arboreal vipers, having a prehensile tail and often lying flat against the bark of trees in the forest.
They are distributed from southern Mexico to northern South America.