Rainbow Boa Fact File
The rainbow boa is a species of non-venomous snake found in South America.
They are named for the iridescent sheen which their scales take on in the sun. This is a result of a chemical found in the scales rather than the actual coloration of it.
As they are non-venomous they must rely on catching their prey with the teeth and then squeezing it to subdue it. They will hunt for small mammals, birds, frogs and lizards all of which are swallowed whole.
These animals were previously captured and exported in large numbers for the pet trade but captive breeding has helped to reduce this demand. Habitat destruction is an ongoing threat.
Read on to learn more about these remarkable reptiles.
The rainbow boa is named for the iridescent sheen taken on by its scales when exposed to sunlight. Across the body they are colored brown or reddish-brown. This is patterned with black blotches along their length. On top of the head are three parallel stripes.
While their appearance may seem bold to us it actually breaks up their outline and allows them to camouflage on the forest floor.
Their patterning is highly variable between individual rainbow boas and subspecies.
They have head which while not large is distinct from the neck.
Adults reach an average length between 1.5 and 2m (5 and 6.5ft) long with a weight of 0.9-1.4kg (2-3lbs). Males tend to have a thicker base of the tail due to the presence of the hemipenes.
Rainbow boas are carnivores. They primarily seek out warm blooded prey items which may include birds and small mammals. Younger animals tend to focus on nestlings and small lizards or frogs.
As a boa they are nonvenomous and will constrict their prey before swallowing it whole.
Prey is located with the assistance of heat-sensitive pits located on either side of the face. Rainbow boas tend not to actively seek out prey instead adopting a sit and wait mentality.
South America is the home of the rainbow boa.
They make their home in forests, woodlands, plains and savanna.
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In the Brazilian subspecies breeding takes place from November to January but this likely varies among subspecies.
Rainbow boas gives birth to live young with anywhere from 2-35 young produced in a single clutch. These develop in an egg within the female, hatch inside and are then born alive. They emerge after a 5 month gestation period.
At birth the young average 38-50cm (15-20in) long.
Young are independent from birth and start hunting at just one week old.
Sexual maturity is primarily tied to length rather than age but tends to fall between 2.5 and 4 years old. Females mature at 1.4m (4.5ft) with males maturing at 1.2m (4ft) long.
Rainbow boas are nocturnal and emerge at night to hunt. The day is spent resting.
In southern subspecies they will undergo a period of hibernation for part of the year.
They are considered partly arboreal with much of their time at rest spent in a tree or bush while feeding primarily occurs on the ground.
Rainbow boas are considered successful swimmers and will sometimes hunt amphibians at the waters edge.
Predators and Threats
Natural predators of the rainbow boa include birds of prey and small carnivores.
Their iridescent sheen has made these snakes one of the most popular in the pet trade. During the 1980s large numbers were exported to supply this demand but captive breeding has gradually helped to reduce this demand.
Humans continue to threaten rainbow boas through habitat destruction and encroachment. In some villages they are welcomed as they will help to reduce populations of rodents.
Five subspecies of the rainbow boa are recognized though some are currently disputed. One of the best known is the Brazilian rainbow boa which is often seen in captivity such as in zoos.
These animals are also known as the slender boa.
Rainbow boas are considered a primitive snakes and the two hind legs can still be seen as spurs on either side of the cloaca.
The scales of the rainbow boa are not the bold colors seen when in the sun. Instead they turn this way due to the presence of chemicals known as purines in their epidermis.
Bernard DUPONT from FRANCE, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons
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