Bio Facts: Boa, Amazon Tree
Amazon Tree Boa
Corallus hortulanus hortulanus
South America in southern Colombia east of the Andes, southern Venezuela, Guyana, Suriname, French Guiana, Amazonian Brazil, Ecuador, Peru and Bolivia
Very humid Amazon rainforest, but may also be found in dry areas such as savannas or dry forests
Adults grow to an average of 53.15” (135 cm) in length. This species exhibits an infinite variety of colors and patterns. The basic color can be anywhere from black, brown, or gray, to literally any shade of red, orange, yellow, or any color in between. Some are totally patternless, while others may be speckled, banded, or saddled with rhomboid or chevron shapes. Some reds will have yellow patterns; some yellows may have red or orange patterns. The ‘garden phase’ refers to boas with drab coloration, mostly brown or olive, with varied patterning, while the ‘colored phase’ refers to animals with combinations of red, orange, and yellow coloring. The eyes can be yellowish, grayish, or reddish, and they have a reflective membrane that results in eyeshine at night. The tongue is black. Males and females are similar in size and markings.
About 15 years in captivity; wild longevity is unknown.
About 3 years of age
In the wild they eat birds, bats, frogs, rodents, lizards, and small mammals; in the Zoo they are fed rodents.
Most Corallus hortulanus specimens studied are found 3’ to 6’ (1-2 m) or more above the ground in trees or other vegetation. They have also been observed active on the ground. Amazon tree boas are also relatively common along rivers (Martins & Oliveira 1999). Corallus hortulanus is a notoriously aggressive species. When approached, it bites and makes an s-coil. When manipulated, it may form into a ball, constrict and rotate the body (Martins & Oliveira 1999). They are solitary and may be active at night and during the day.
Amazon tree boas hunt at night using their infrared sensitivity or during the day using vision. They are typically ambush hunters, sitting on a branch with the front part of their body hanging in an S-shaped curve from the branch. They can strike at prey that is a surprising distance from them. Prey is often pushed off the tree branch as it is struck. When this happens the snake gathers the body in several of its coils.
There is little information on wild mating. In an attempt to at least provide some relevant information, captive breeding techniques from one thorough description are summarized below:
Beginning in early November, evening temperatures drop from the stable summer temperatures of 77° to 78°F to a nightly low of about 70° to 72°F by the first week of December. This change is as gradual as possible in captivity. At the same time, a daytime high of 83° to 85°F is introduced. These temperature gradients are important in triggering mating behaviors. After approximately 2 months of exposure to these new temperatures, most males will begin to display courtship behavior. Frequently males will shed shortly before beginning courtship. The courtship behavior consists of “tail-writhing” around the enclosure. After this has begun, the male and female are introduced and the male’s courtship behavior will induce ovulation in the female. Females are also more receptive to mates if they are introduced shortly after a shed. Around March to April, the pair will have begun actively copulating. The snakes will copulate multiple times during this period. In captivity it is possible to have one female mate with multiple males, though this is not recommended as the males will often become highly aggressive and fight each other. In some cases, high levels of male aggression have been noted resulting in a dangerous situation for the female. (Mendez, 2000)
In Amazon tree boas, ovulation occurs in the female several weeks after copulation. During gestation period, females seek areas in direct sunlight or other warm areas to bask. Amazon tree boas give birth to live young. The gestation period is 6 to 8 months. After the young are born they are immediately independent of their mother. Male Amazon tree boas do not contribute to the care of their young. Newborns will shed their skin 8 to 14 days after birth. After about 3 years, Amazon tree boas will reach sexual maturity.
Amazon tree boas have particularly large infrared pits, which allow them to sense heat well. An extensive study by Ebert et. al. (2006) examined the structure of these pits. They also have good eyesight that they use to hunt during the day. As are most snakes, Amazon tree boas are sensitive to vibrations and have good chemoreception, which is often used in communicating reproductive information.
The name “hortulanus” is derived from the Latin word for “gardener” and came from the pattern on the tops of their heads resembling a flower garden.
There are two subspecies of Amazon tree boa. Corallus hortulanus hortulanus occurs in the Guianas, Amazonia, and south-eastern Brazil (to the Tropic of Capricorn). Corallus hortulanus cookii is found in southern Central America, northern Columbia, northern Venezuela, Trinidad and Tobago, and the southern Windward Islands (St. Vincent and the Grenada Bank). Corallus hortulanus is distinguishable from other species in the complex by the maximum number of dorsal scale rows (almost always over 50 in hortulanus, always less than 50 in cookii, grenadensis, and ruschenbergerii). Populations of hortulanus with less than 50 dorsal scale rows occur in Guyana, Suriname, Bolivia, and Peru. In general, hortulanus has higher counts for meristic characters than other members of the complex. The shape of the main element in the dorsal pattern at midbody is more or less ellipsoidal, whereas it is a ragged hourglass in cookii and is usually spade-shaped in grenadensis [from HENDERSON 1997].
Amazon tree boas are popular pets for snake hobbyists and are a fairly common export in the pet trade. About 3,000 of these snakes were exported live from Guyana in 2002, and 1,902 were exported from Suriname in the same year (CITES 2002).
Corallus hortulanus cookii (also sometimes known as Corallus cookii) was once commonly traded. However, this type of tree boa is native to only one island (St. Vincent), which has stopped exporting herpetofauna for commercial purposes (Mendez 2001).
Jacksonville Zoo History:
Amazon tree boas have been part of our animal collection off-and-on since at least 1965. We had this species on our inventory in about 1965-1967; 1981-1986; and they once again arrived in 2004. This species has bred here.