Rainforests hold the highest diversity of snake species in the world. Despite the fact that many of these snakes represent different ancestral lineages, several of the species living inside jungles have evolved green coloration to help them camouflage in the trees. While most of these snakes use crypsis to avoid predators and sneak up on prey, they have adapted to fill many different niches and hunt for a wide variety of prey species.
Convergent evolution occurs when two distantly related taxa independently develop similar adaptations. Green tree pythons (Morelia viridis) and emerald tree boas (Corallus canninus) are one of the best examples of this in snakes -- separated by tens of millions of years of evolution, both species have evolved striking similarities. Both species utilize highly developed infrared imaging systems, which allows them to see in the dark; have laterally compressed, powerful bodies to cling to the trees; and though boas bring forth live young and green tree pythons lay eggs, the young of both species are colored differently than the adults are. Though they turn green over their first year or two of life, most young tree boas are red or orange in color, while hatchling tree pythons are yellow, red or brown. You can also find examples of convergence among the many different evolutionary lineages that have produced distantly related, but similar-looking and -behaving vine snakes in Asia, Africa and Central America.
Green rainforest snakes rely heavily on camouflage to survive, and many are virtually invisible, hiding within the foliage. To prevent them from betraying their otherwise effective camouflage, the snakes’ eyes are often intricately marked to disrupt their outline. Additionally, few snakes are completely green; most have scattered white, black or yellow markings that provide further camouflage, which mimics lichen, shadows and patches of sunlight, respectively.
Collectively, green snakes of the rainforest consume a wide variety of prey. Adults of the smallest species, and juveniles of the larger species, consume insects and invertebrates, such as moths, beetles and caterpillars. Most of the medium-sized species specialize on lizard and frog prey; especially three different genera of arboreal, green snakes -- Ahetulla, Chironius and Oxybelis -- colloquially called vine snakes. Large green snakes of the rainforest -- such as emerald tree boas, green tree pythons (Morelia viridis) green mambas (Dendroaspis viridis) and Wagler’s vipers (Tropidolaemus wagleri) -- consume rodents, bats and birds.
Prehensile and Enticing Tails
Most green snakes living in the rainforest are arboreal. As a general trend, arboreal species evolve prehensile tails that they use to grasp branches. Many of these tree-dwelling snakes can support their entire body weight while hanging from their tail. Some arboreal species -- notably green tree pythons -- have differently colored tails; in a behavior termed “caudal luring,” the snakes wiggle their tails enticingly like a worm, to attract lizards and frogs into striking range.
- Devenomized.com: Captive Care of the Western Green Mamba Dendroaspis Viridis
- Blue Planet Biomes: Wagler's Pit Viper
- Animal Diversity Web: Morelia Viridis
- Herpetological Conservation and Biology; Field Observations on the Behavioral Ecology of the Madagascan Leaf-Nosed Snake, Langaha Madagascariensis; Jessica L. Tingle
- Signal Herpetoculture: Emerald Tree Boas