Amazon Tree Boa (Corallus enydris)
Order: Squamata, Family: Boidae
The Amazon Tree Boa is one of the most geographically widespread and frequently encountered species of neotropical snakes. The boas' range stretches from southwestern Costa Rica, Panama, and northern South America, through most of Venezuela and Guyana, and south and westward through Amazonian Columbia, Ecuador, Peru, Bolivia, and Brazil. This species was introduced to small islets off the Atlantic and Pacific shores of Panama, Trinidad and Tobaga, and Grenada.
I. GEOGRAPHIC RANGE
II. PHYSICAL DESCRIPTION
- The Amazon Tree Boa is one of the most geographically widespread and frequently encountered species of neotropical snakes. The boas' range stretches from southwestern Costa Rica, Panama, and northern South America, through most of Venezuela and Guyana, and south and westward through Amazonian Columbia, Ecuador, Peru, Bolivia, and Brazil. This species was introduced to small islets off the Atlantic and Pacific shores of Panama, Trinidad and Tobaga, and Grenada.
- Native: Neotropical
- Amazon Tree Boas have small nostrils and large eyes with elliptical, vertical pupils for nocturnal foraging and long teeth for catching sleeping birds. They have slender bodies and long, prehensile tails, which adapt them for a life in the trees. Amazon Tree Boas have very distinctive heads. The heads are large, bulky, and clearly distinctive from the thin neck. Amazon Tree Boas are also well-adapted for an arboreal life. Their general color is brown, ochre, and grey, but they can also be red orange, and yellow. They have white markings making them almost invisible in the trees. Their tails are marked with bold red, with black and yellowish dots. Females have different coloration than males and a smaller head relative to the body.
- Length: 3 m (max) female larger; female more colorful; sexes shaped differently; bilateral symmetry; cryptic
Orange Amazon Tree Boa
- There is evidence that the lifespan of a snake is related to its size. This would mean that boas are among the longest lives snakes, because they are undoubtedly the largest. The lifespan of an Amazon Tree Boa is unknown. It is estimated, however, that boa constrictors can reach an age of 40-50 years if an enemy or a disease prior does not kill them. In captivity, the longest lived (an anaconda) was held in the National Zoo in Washington D.C. for 28 years.
- Boas take a long time to reach their great circumference and weight. They grow rapidly until they approach 2-3 meters in length, then growth slows. Tree Boas average between 2 and 3 meters long, but some can grow longer. Female boas grow larger than males. When in captivity, large boas reach sexual maturity in three years.
VI. ECOSYSTEM ROLES
- Tree Boas are arboreal and they have unique adaptations in their scale color that makes them less susceptible to predators. Their color, a mixture of brown, white, ochre, and sometimes gray, camouflages them when they are in trees.
- Predators: harpy eagle, humans, saddleback tamarin
VII. FOOD HABITS
- Boas are middle-level predators, eating smaller animals, but in turn eaten by others. They are among the largest arboreal predators in the tropics of the Western Hemisphere.
- Boas are nonvenomous, constricting snakes. They bite their prey to hold it, but kill by squeezing their prey until it suffocates. All boas have heat-sensitive grooves between the labial scales under their nostrils that they use to locate warm-blooded prey, even in total darkness.
- Amazon Tree Boas have a relatively long striking distance compared to other snakes. The boas grab their prey with a quick striking motion. If the attack is in the treetops, the boa pushes off the branch with the strike. As the prey's body falls, boas throw one to three coils around the prey while they dangle from the branch with their prehensile tails. Once the boas seize and kill their prey, they consume it slowly. They release the dead prey, sniff it, and begin the eating process at the head.
- Snakes can loosen the upper and lower jaw from their linkage because they are only joined by ligaments. This enables them to open their mouth very wide. The Amazon Tree Boa is eurytrophic (wide range of diet), and their diets vary both ontogenetically and geographically.
- When boas are young, they prey on small birds. As they mature, their diets shift to larger mammals. Although large snakes can swallow huge amounts at a single time, they actually eat modest amounts and require just a little more than their own weight of food per year. The normal feeding period is about one small rodent every ten days. Once they become adults, they have longer time increments between meals. Adult boas can go for weeks and can even fast for several months without losing any significant amount of weight.
- Foods eaten: bats, birds, lizards, rodents, opossums, small reptiles, small mammals
- Amazon Tree Boas, like all boas are live bearing (viviparous). When female boas are pregnant, they spend more time basking (warming their bodies), which accelerates the development of their babies. They produce between thirty to eighty baby boas at a time. These boas are approximately 0.7m long at birth.
- Females usually only reproduce once per year. This is because the female Tree Boas find difficulty gathering enough energy between seasons to breed more frequently. If the food supply is limited during the months before they give birth, female Amazon Tree Boas may produce and then eat unfertilized egg masses. It is believed that this is done to prevent predators from picking up on the scent of the unfertilized ovum as well as to regain some nutrients and energy sources lost during gestation.
- Year-round breeding; sexual; internal; viviparous
- After birth, young Amazon Tree Boas quickly disperse.
- No parental care
- The slender bodies and prehensile tails of Amazon Tree Boas make them excellent climbers. Oddly enough, Tree Boas are even better in water than on land. They use their agility, diving and surfacing. When swimming, they pump air inside their bodies, preventing them from sinking. They are nocturnal, moving and hunting at night.
- Nocturnal; motile; solitary
XI. ECONOMIC IMPORTANCE FOR HUMANS
- The Amazon Tree Boa has been found abundantly in evergreen wet and rainforest, banana plantations, mangroves, fruit orchards, cactus and thorn scrub habitats. They are arboreal, climbing climb trees that are large enough to support their body weight. They usually reside close to streams where the taller trees with stronger branches are found.
- Tropical; forest, rainforest, scrub forest; swamp; agricultural, riparian
Tree boas may provide some benefit to humans by eating pest rodents. They are also kept as pets, or living curios.
Pet trade; produces fur, leather or wool; controls pest population
These snakes have no negative effects on humans. They bite only in self-defense, and are not venomous. Many species of boas are killed for their skins.
XIII. OTHER COMMENTS
- Few people in the past have shown an interest in the preservation of snakes, not to mention Tree Boas. Boas in general, are killed by humans because they are slow moving and easy to kill, and because they possess valuable skin and meat. Amazon Tree Boas are popular as pet trade, and there can be many snakes that die during the process of capture and international shipping. Fortunately captive breeding has also become popular. This is species is considered abundant and not in immediate danger.
- It is important to educate people on boas and on their harmlessness to humans.
- The Amazon Tree Boa (also called the Garden Tree Boa and Cook's Tree Boa), is often referred to as Corallus enydris and has also been called Corallus cookii. The correct scientific name is Corallus hortulanus. The genus Corallus is still the subject of scientific study, and species are still being described and reclassified.