Corallus caninus (Linnaeus, 1758)

Adult Size

Adult Corallus caninus (emerald tree boas) typically reach about 6 feet (1.8 m) in length.

Dental Morphology

They have highly developed front teeth that are proportionately larger than those of any other non-venomous snake.

Adult Color Pattern

Their typical color pattern has an emerald green base color, with an irregular, interrupted white zigzag stripe (often called 'lightning bolts') running down the back, and a yellow belly. This bright, distinct patterning sets them apart from other South American snakes.

Juvenile Coloration

Juveniles show a range of light to dark orange or brick-red colors before undergoing ontogenetic color change, turning full emerald green between 9 and 12 months of age.

Interspecific Color Shift Comparison

This same ontogenetic color shift also occurs in the green tree python Morelia viridis, where hatchlings and juveniles can also be canary yellow or brick-red. Contrary to common belief, Corallus caninus does not have yellow juvenile individuals like the green tree python.

Taxonomic Debate

Some herpetologists have debated whether a locality-based morphological variant of this snake should be classified as a separate species, and the recently proposed name for this variant is Corallus batesii [Henderson].

Amazon Basin Population Size and Temperament

Specimens from the Amazon River basin tend to be the largest, growing 7–9 feet (2.1–2.7 m) long, and are much more docile than northern populations; the overall average size of the species remains closer to 6 feet (1.8 m).

Peruvian Population Coloration

Specimens from the southern end of the species' range in Peru tend to be darker in color.

Regional Dorsal Marking Variation

Amazon Basin specimens usually have an uninterrupted white dorsal line, while white markings on specimens from Guyana and Surinam (called "Guyana Shield" or "Northern" emerald tree boas) are quite variable.

Regional Snout Scale Variation

Amazon Basin specimens also have much smaller snout scales than northern, southern, and western populations found in locations including Suriname, Venezuela, Bolivia, and French Guiana.

Hybridization Record

Hybrids between the Northern Shield Corallus caninus and the Amazon Basin variant are known to exist.

Convergent Evolution with Green Tree Python

The emerald tree boa looks very similar to the southern green tree python (Morelia viridis), which is native to Southeast Asia and Australia. This similarity is an example of convergent evolution, as the two species are only very distantly related.

Species Distinguishing Features

They can be distinguished by physical differences in head scalation and the placement of heat pits around the mouth.

Core Species Range

The species is found in northern South America, in northern Colombia, northern Brazil, and across the area from Venezuela to Suriname and the Guianas, within the Guiana Shield.

Type Locality

The original type locality is recorded only as "Americae."

Amazon Basin Variant Range

The Amazon Basin variant, as its name suggests, is found only along the Amazon River basin, in southern Suriname, southern Guiana, southern Venezuela extending to Colombia, Peru, and Brazil, in the surrounding jungles of the Amazon River.

Reproductive Mode

The emerald tree boa is ovoviviparous.

Litter Size

Females produce an average of 6 to 14 young per litter, and larger litters are extremely rare.

Juvenile Color Change Timeline

Newly born juveniles have a characteristic brick-red to orange coloration, and gradually complete their ontogenetic color change over 12 months to become fully emerald green.