Corallus caninus
emerald tree boa

Emerald tree boas are found in lowland tropical rainforests in the Amazonian and Guianan regions of South America. They occur in northern Brazil, eastern Peru, southern Colombia, southern Venezuela, French Guiana, eastern Ecuador, Suriname, Guyana, and the exreme north of Bolivia. (Henderson, 2005; Kivit and Wiseman, 2000)

Emerald tree boas are found at elevations ranging from sea level to 1000 m above sea level (average = 200 m). They are aboreal species that spend most of their time in the rainforest canopy foliage. They have been found in both primary and secondary vegetation, and also in swamp forest. Although they are arboreal, they do occasionally descend to the ground to bask in the sun. They are found in the Amazon Basin and often found alongside rivers, but are not dependent on open water. They are found in areas that recieve an excess of 1500 mm of rain annually. (Henderson, 2005; Kivit and Wiseman, 2000; Stafford and Henderson, 1996; Vidal et al., 2005a)

Emerald tree boas are called "emerald" because of the exquisite green coloration on their dorsal surfaces. Many populations have striking white markings occurring along the dorsal midline, although some individuals lack them. Other individuals have black coloration on the dorsum. Juveniles range from a brown to red color. Emerald tree boas can grow to be over 2 m in length. Male emerald tree boas are usually smaller in size, more "wiry" and have larger spurs. (Henderson, 2005; Vidal et al., 2005a)

At birth, emerald tree boas can be from 40 to 50cm long and can weigh 20 to 50 g. The young are a reddish-brown color. By 4 months, they begin to develop their adult, green coloration. (Groves, 1978; Kivit and Wiseman, 2000)

There are no data about the longevity of emerald tree boas in the wild. In captivity, one was kept over 15 years. This snake was received at a zoo when it was already an adult. It is believed that they can live well over 20 years. (Kivit and Wiseman, 2000)

Emerald tree boas spend most of their time in wet, lowland rainforests, living in the canopy foliage of trees and in shrubs. During the day they remain inactive, looped over a horizontal branch. They form an ellipsoidal coil with their bodies, with the head in the center. As ambush predators, they catch most prey by snatching them off the ground as they hang from these branches.

Agnostic behavior has been observed between males housed together in captivity with a female. Observed aggression between males consists of chasing, mounting, and writhing body movements until one male finally becomes dominant. Then the dominant snake continues to pursue the other male to overpower it, using the posterior part of the body to constrict the neck area. This behavior was observed when two males were located on the same, or nearby horizontal branches. No biting was observed. Also, on occasion, the dominant male was observed to attack and constrict the female. (Kivit and Wiseman, 2000; Stafford and Henderson, 1996)

Home Range

Population densities have been estimated at one snake per 2.7 square kilometers. (Kivit and Wiseman, 2000)

Emerald tree boas perceive prey primarily through sight and infrared heat receptors located in the labial scales. These heat-sensitive pits are critical for locating prey at night. Like other snakes, they also use their tongues and vomeronasal organs to sense chemical cues and they can detect vibrations. Corallus caninus is a solitary species that interacts primarily with a mate and also with prey. Occasionally, aggressive behavior occurs when males get extremely close to one another. (Kivit and Wiseman, 2000)

Emerald tree boas are nocturnal predators of rodents, lizards, and marsupials. Some researchers suggest that they also prey on birds, but stomach content analyses have failed to support this. Observations strongly suggest that emerald tree boas are ambush predators that hang near the ground and angle their heads downward to ambush passing rodents. (Henderson, 2005; Vidal et al., 2005a)

The only known predators of Corallus caninus are Guianan crested eagles (Morphnus guianensis). Emerald tree boas are cryptically colored and generally remain hidden in the foliage of trees. (Kivit and Wiseman, 2000)

Corallus caninus may help control small mammal populations, especially rodents. It is also a food source for Guianan crested eagles (Morphnus guianensis).

Few studies have examined parasites of emerald tree boas. However, one article found a blood parasite (Hematozoon species) in 3 of 4 tested individuals in French Guiana. Captive emerald tree boas have also been infected by the parasite that causes cryptosporidiosis (Cryptosporidium serpentis). (de Thoisy et al., 2000; Funk, 1987; Kivit and Wiseman, 2000)

No available literature discussed negative economic impacts.

Emerald tree boas have become increasingly desirable in captivity in recent years. Their beauty provides aesthetic benefits for humans. They also help to control rodent populations, which can be pests near human habitation. (Kivit and Wiseman, 2000)

The conservation status of this species is unknown, as it is not in the IUCN database, and CITES does not list it as a species of concern.

In captivity, although emerald tree boas are slow-moving snak, they are generally regarded as aggressive. Specimens collected in the wild have been described as making no effort to escape until seized, whereupon they strike viciously and apply constriction at full force. After the initial struggle, they will relax and seem to "accept" captivity.