Corallus hortulanusGarden Tree Boa

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Geographic Range

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 cooki is found in southern Central America, northern Columbia, northern Venezuela, Trinidad and Tobago, and the southern Windward Islands (St. Vincent and the Grenada Bank). (Henderson, 1997)

Habitat

Amazon tree boas are found in a wide variety of habitats. They are common in arboreal regions with high humidity, especially Amazon rainforest. They can also be found in dry areas such as savannas or dry forests (Huang 2006).

Most Corallus hortulanus specimens studied are found 1 to 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). (Huang, 2006; Martins and Oliveira, 1999)

  • Range elevation
    0 to 900 m
    0.00 to 2952.76 ft

Physical Description

Corallus hortulanus is well known for its highly variable color and patterns. They have small, claw-like remnants of vestigial hindlimbs in the cloacal region. Their base color varies from pale tan to black, with yellowish and reddish tinges. They are marked by a series of blotches or bands that are often broader in the middorsal area. The head has five dark stripes that extend from the eyes. The venter color is also variable, from cream to reddish brown, and either with or without darker markings. 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. They range from 525 to 1880 mm in length, usually from 1200 to 1500 mm (Martins & Oliveira 1999). (Martins and Oliveira, 1999)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    525 to 1880 mm
    20.67 to 74.02 in
  • Average length
    1200-1500 mm
    in

Reproduction

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 degrees F to a nightly low of about 70 to 72 degrees 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 degrees 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. Newborns will shed their skin 8 to 14 days after birth. After about 3 years, Amazon tree boas will reach sexual maturity. (Mendez, 2000)

  • Breeding interval
    Amazon Tree Boas breed once yearly.
  • Breeding season
    Copulation occurs between March and May.
  • Range gestation period
    175 to 200 days
  • Average gestation period
    225 days
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

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. (Mendez, 2000)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female

Lifespan/Longevity

Wild records of longevity are not available in the literature. Average lifespans for Amazon tree boas in captivity are approximately 20 years.

  • Typical lifespan
    Status: captivity
    20 (high) years

Behavior

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.

Communication and Perception

Most members of the family Boidae possess infrared sensitive receptors in labial pit organs. 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 IR 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.

Food Habits

Amazon tree boas have been reported to eat: birds (including Chloroceryle inda, Coereba, Elaenia), bats (probably Phyllostomus bicolor, Myotis), frogs (Elachistocleis), rodents (Akodon, Mus, Rattus), lizards (Anolis, Basiliscus, Iguana), and marsupials (Marmosa). These observations suggest that Corallus hortulanus has a broad diet of mainly vertebrate prey. (Martins and Oliveira, 1999)

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 are a surprising distance from themselves. Prey are often pushed off the tree branch as they are struck, in which cases the snake will gather the body in several of its coils. (Huang, 2006; Martins and Oliveira, 1999)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles

Predation

It has been proposed that the color patterns of Amazon tree boas helps to camouflage them from predators during the day (Martins & Oliveira 1999). (Martins and Oliveira, 1999)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Corallus hortulanus are important predators of vertebrates in their native ecosystems.

Economic Importance for Humans: Positive

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 Guiana in 2002, and 1,902 were exported from Suriname in the same year (CITES 2002).

Corallus 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) ("Export quotas for specimens of species included in the CITES appendices for 2002", 2002; Mendez, 2001)

Economic Importance for Humans: Negative

Amazon tree boas are aggressive and will attack humans without warning, though only adults pose any serious danger to humans as this species is non-venomous. (Martins and Oliveira, 1999)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Amazon tree boa populations are not considered to be at risk.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Kevin Winner (author), University of Maryland, Baltimore County, Kevin Omland (editor, instructor), University of Maryland, Baltimore County.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

diurnal
  1. active during the day, 2. lasting for one day.
forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

induced ovulation

ovulation is stimulated by the act of copulation (does not occur spontaneously)

infrared/heat

(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

ovoviviparous

reproduction in which eggs develop within the maternal body without additional nourishment from the parent and hatch within the parent or immediately after laying.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

References

Global Biodiversity Information Facility. 2007. "Corallus hortulanus (Gartenboa)" (On-line). GBIF Portal. Accessed April 23, 2008 at http://data.gbif.org/species/13493398.

2002. "Export quotas for specimens of species included in the CITES appendices for 2002" (On-line). Accessed April 23, 2008 at http://www.cites.org/common/quotas/2002/latest.pdf.

Ebert, J., A. Schmitz, G. Westhoff. 2006. Surface structure of the infrared sensitive pits of the boa Corallus hortulanus. Proceedings of the 13th Congress of the Societas Europaea Herpetologica, 13: 215-217. Accessed April 23, 2008 at http://www.gli.cas.cz/seh/files/bonnensis/215_Ebert.pdf.

Franca, F., D. Mesquita, G. Colli. 2006. A Checklist Of Snakes From Amazonian Savannas In Brazil. Occasional Papers, 17: 1-13. Accessed April 23, 2008 at http://www.unb.br/ib/zoo/grcolli/publicacoes_pdf/Francaetal2006.pdf.

Henderson, R. 1997. A Taxonomic Review of the Corallus hortulanus Complex of Neotropical Tree Boas. Caribbean Journal of Science, 33: 198-221. Accessed April 23, 2008 at http://academic.uprm.edu/publications/cjs/VOL33/P198-221.PDF.

Huang, P. 2006. "Introduction" (On-line). Corallus.com. Accessed April 23, 2008 at http://www.corallus.com/hortulanus/index.html.

Martins, M., M. Oliveira. 1999. Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History, 6: 78-150. Accessed April 23, 2008 at http://eco.ib.usp.br/labvert/Martins&Oliveira-HNH-1999.pdf.

Mendez, D. 2001. "An Introduction to Amazon Tree Boas by DM" (On-line). Accessed April 23, 2008 at http://www.urbanjungles.com/bamazontreeboasb.htm.

Mendez, D. 2000. "Breeding Treeboas" (On-line). Urban Jungles. Accessed April 23, 2008 at http://www.urbanjungles.com/breedingtreeboas.htm.