Boa constrictor
Overview
For other uses, see Boa constrictor (disambiguation)
Boa Constrictor (disambiguation)
Boa constrictor may refer to:* Boa constrictor, a large South American constricting snake. This is both its scientific and common name.* A song by Shel Silverstein from his 1962 album Inside Folk Songs...


The Boa constrictor (Boa constrictor) is a large, heavy-bodied species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

. It is a member of the family Boidae found in North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

, and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, as well as some islands in the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

. A staple of private collections and public displays, its color pattern is highly variable yet distinctive. Ten subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 are currently recognized, although some of these are controversial.
Encyclopedia
For other uses, see Boa constrictor (disambiguation)
Boa Constrictor (disambiguation)
Boa constrictor may refer to:* Boa constrictor, a large South American constricting snake. This is both its scientific and common name.* A song by Shel Silverstein from his 1962 album Inside Folk Songs...


The Boa constrictor (Boa constrictor) is a large, heavy-bodied species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

. It is a member of the family Boidae found in North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

, and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, as well as some islands in the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

. A staple of private collections and public displays, its color pattern is highly variable yet distinctive. Ten subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 are currently recognized, although some of these are controversial. This article focuses on the species Boa constrictor as a whole, but also specifically on the nominate subspecies Boa constrictor constrictor.

Common names

Though all boids are constrictors
Constriction
Constriction is a method used by various snake species to kill their prey. Although some species of venomous and mildly-venomous snakes do use constriction to subdue their prey, most snakes which use constriction lack venom. The snake initially strikes at its prey and holds on, pulling the prey...

, only this species is properly referred to as "Boa constrictor"; an almost unique instance of an animal having the same common and scientific binomial name
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...

. (The distinction is shared with Tyrannosaurus rex.) Hence, the Boa constrictor is the only living animal to have this distinction.

All subspecies are referred to as "Boa constrictors", while the nominate subspecies, B. c. constrictor, is often referred to specifically as the "red-tailed boa". Within the exotic pet trade it is also known as a "BCC", an abbreviation of its scientific name, to distinguish it from other Boa constrictor subspecies such as the Boa constrictor imperator
Boa constrictor imperator
Boa constrictor imperator is a nonvenomous boa subspecies found in Central America.-Description:B. c. imperator is wide-ranging, with animals living in both Central America and northern parts of South America...

 which is also regularly, and erroneously, referred to as a "red-tailed boa".

Other common names include "jibóia" (Latin American) and "macajuel" (Trinidadian
Trinidad and Tobago
Trinidad and Tobago officially the Republic of Trinidad and Tobago is an archipelagic state in the southern Caribbean, lying just off the coast of northeastern Venezuela and south of Grenada in the Lesser Antilles...

, pronounced mah-cah-well).

Size and weight

The Boa constrictor is a large snake, although only modestly sized in comparison to other large snakes such as the reticulated
Reticulated Python
Python reticulatus, also known as the reticulated python is a species of python found in Southeast Asia. Adults can grow to over 8.7 m in length but normally grow to an average of 3-6 m . They are the world's longest snakes and longest reptile, but are not the most heavily built...

 and Burmese python
Burmese Python
The Burmese Python is the largest subspecies of the Indian Python and one of the 6 largest snakes in the world, native to a large variation of tropic and subtropic areas of Southern- and Southeast Asia. They are often found near water and are sometimes semi-aquatic, but can also be found in trees...

, and can reach lengths of anywhere from 1–4 meters (3–13 feet) depending on the locality and the availability of suitable prey. There is clear sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 seen in the species, with females generally being larger in both length and girth than males. As such, the average size of a mature female boa is between 7–10 ft, whilst it is 6–8 ft for the males. It is common for female individuals to exceed 10 ft, particularly in captivity, where lengths of up to 12 ft or even 14 ft can be seen. A report of a Boa constrictor growing up to 18½ ft (5.5 m) was later found to be a misidentified green anaconda.

The Boa constrictor is a heavy-bodied snake, and large specimens can weigh up to 27 kg (60Ibs).

The size and weight of a Boa constrictor depends on subspecies, locale and the availability of suitable prey. Several populations of Boa constrictors are known as "dwarf boas", such as the population of B. c. imperator on Hog Island
Cayos Cochinos
The Cayos Cochinos or Cochinos Cays are a group of two small islands and 13 more small coral cays situated 30 kilometers northeast of La Ceiba on the northern shores of Honduras. Although geographically separate, they belong to the Bay Islands department and are part of Roatán municipality. The...

. These smaller subspecies are generally insular
Insular dwarfism
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals – typically mammals – when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf...

 populations. B. c. constrictor itself reaches, and occasionally tops, the averages given above, as it is one of the relatively large subspecies of Boa constrictor.

Other examples of sexual dimorphism in the species include the fact that males generally have longer tails to contain the hemipenes and also longer pelvic spurs, which are used to grip and stimulate the female during copulation. Pelvic spurs are the only external sign of the rudimentary hind legs and pelvis, seen in all boas and pythons.

Coloring

The coloring of Boa constrictors can vary greatly depending on the locality. However, they are generally a brown, grey or cream base color, patterned with brown or reddish brown "saddles" that become more pronounced towards the tail. It is this coloring that gives Boa constrictor constrictor the common name of "red-tailed boa", as it typically has more red saddles than other boa constrictor subspecies. The coloring works as very effective camouflage in the jungles and forests of its natural range.

There are also individuals that exhibit pigmentary disorders such as albinism
Albinism
Albinism is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes due to absence or defect of an enzyme involved in the production of melanin...

. Although these individuals are rare in the wild, they are common in captivity where they are often selectively bred to make a variety of different color "morphs". Boa constrictors have an arrow-shaped head that has very distinctive stripes on it. One runs dorsally from the snout to the back of the head. The others run from the snout to the eyes and then from the eyes to the jaw.
Boa constrictors can sense heat
Infrared sensing in snakes
The ability to sense infrared thermal radiation evolved independently in several different families of snakes. Essentially, it allows these animals to “see” radiant heat at wavelengths between 5 and 30 μm to a degree of accuracy such that a blind rattlesnake can target vulnerable body parts of the...

 via cells in their lips, though they lack the labial pits surrounding these receptors seen in many members of the boidae family. Boa constrictors also have two lungs, a smaller (non-functional) left and enlarged (functional) right lung to better fit their elongated shape, unlike many colubrid snakes which have completely lost the left lung.

Geographic range

Dependent on subspecies Boa constrictor can be found from northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 through Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 (Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...

, Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

, Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...

, El Salvador
El Salvador
El Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...

, Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...

, Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

 and Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

) to South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 north of 35°S (Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

, Trinidad and Tobago
Trinidad and Tobago
Trinidad and Tobago officially the Republic of Trinidad and Tobago is an archipelagic state in the southern Caribbean, lying just off the coast of northeastern Venezuela and south of Grenada in the Lesser Antilles...

, Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

, Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...

, French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...

, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

, Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

 and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

). Also in the Lesser Antilles
Lesser Antilles
The Lesser Antilles are a long, partly volcanic island arc in the Western Hemisphere. Most of its islands form the eastern boundary of the Caribbean Sea with the Atlantic Ocean, with the remainder located in the southern Caribbean just north of South America...

 (Dominica
Dominica
Dominica , officially the Commonwealth of Dominica, is an island nation in the Lesser Antilles region of the Caribbean Sea, south-southeast of Guadeloupe and northwest of Martinique. Its size is and the highest point in the country is Morne Diablotins, which has an elevation of . The Commonwealth...

 and St. Lucia), on San Andrés
San Andrés (island)
San Andrés is a coral island among the Colombian islands in the Caribbean Sea; it is the largest island of the southern group of islands. Together with the nearby island of Providencia and some smaller islands of the southern group of the Colombian archipelago, San Andrés forms the department of...

, Providencia
Providencia Island
Isla de Providencia or Old Providence is a mountainous Caribbean island. Though it is closer to Nicaragua, it is part of the Archipelago of San Andres, Providencia and Santa Catalina, a department of Colombia, lying midway between Costa Rica and Jamaica...

 and many other islands along the coasts of Mexico and Central and South America.
The type locality given is "Indiis" -- a mistake, according to Peters and Orejas-Miranda (1970).

Habitat

Boa constrictor flourishes in a wide variety of environmental conditions, from tropical rainforests to arid semi-desert country. However, it prefers to live in rainforest due to the humidity
Humidity
Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...

 and temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

, natural cover from predators and vast amount of potential prey. It is commonly found in or along rivers and streams, as it is a very capable swimmer. Boa constrictor will also occupy the burrows
Burrows
Burrows is a provincial electoral division in the Canadian province of Manitoba. It was created by redistribution in 1957, and formally came into existence in the provincial election of 1958. The riding is located in the northern part of Winnipeg....

 of medium-sized mammals, where it can hide from potential predators.

Behavior

Boa constrictors are solitary animals, and will only associate with conspecifics to mate. They are nocturnal, however they may bask during the day when night-time temperatures are too low. As semi-arboreal snakes, young boa constrictor individuals may climb into trees and shrubs to forage, however they become mostly terrestrial as they become older and heavier. Boa constrictors will strike when threatened, and will bite in defense. This bite can be painful, especially from large snakes, but is rarely dangerous. However, care must be taken to ensure that infection does not result from the injury. Specimens from Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 are more irascible, hissing loudly and striking repeatedly when disturbed, while those from South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 tame down more readily. Like all snakes, Boa constrictors that are in a shed cycle will be more unpredictable. This is because the substance that lubricates between the old skin and the new will make the eyes appear "milky" or "opaque", and as such the snake cannot see very well. This will cause it to be more defensive than it may be otherwise.

Diet

Prey includes a wide variety of mammals and birds. The bulk of their diet consists of rodents, but larger lizards and mammals as big as ocelot
Ocelot
The ocelot , pronounced /ˈɒsəˌlɒt/, also known as the dwarf leopard or McKenney's wildcat is a wild cat distributed over South and Central America and Mexico, but has been reported as far north as Texas and in Trinidad, in the Caribbean...

s are also reported to have been consumed. Young Boa constrictors will eat small mice
MICE
-Fiction:*Mice , alien species in The Hitchhiker's Guide to the Galaxy*The Mice -Acronyms:* "Meetings, Incentives, Conferencing, Exhibitions", facilities terminology for events...

, birds, bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...

s, lizards and amphibians. The size of the prey item will increase as they get older and larger.

Boa constrictors are ambush predators and as such will often lie in wait for an appropriate prey to come along at which point they will attack. However, they have also been known to actively hunt, particularly in regions with a low concentration of suitable prey, and this behaviour generally occurs at night. The boa will first strike at the prey, grabbing it with its teeth, it then proceeds to constrict the prey until death before consuming it whole. Their teeth also help force the animal down the throat whilst muscles then move it towards the stomach. It will take the snake approximately 4–6 days to fully digest the food, depending on the size of the prey and the local temperature. After this the snake may not eat for anywhere from a week to several months, due to its slow metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

.

Reproduction and development

Boa constrictors are ovoviviparous
Ovoviviparity
Ovoviviparity, ovovivipary, or ovivipary, is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch...

, giving birth to live young. They will generally breed in the dry season—between April and August—and are polygynous, thus males may mate with multiple females. A half of all females will breed in a given year, and a larger percentage of males will actively attempt to locate a mate. However due to the polygynous nature of Boa constrictor many of these males will be unsuccessful. The reasoning being the fact that they are ovovivparous. As such female boas without a good enough physical condition will be unlikely to attempt to mate, nor produce viable young if they do mate. In 2010, a boa constrictor was shown to have reproduced asexually via parthenogenesis
Parthenogenesis
Parthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...

.

During breeding season the female boa will emit a scent from her cloaca to attract males, who may then wrestle for the right to breed with her. During breeding the male will curl his tail around the females and the hemipenes will be inserted. Copulation can last from a few minutes to several hours, and may occur several times over a few week period. After this period ovulation may not occur immediately, however the female can hold the sperm inside her for up to one year. When the female ovulates, a mid-body swell can be noticed that appears similar to after the snake has eaten a large meal. The female will then shed 2 to 3 weeks after ovulation, with what is known as a post ovulation shed which will last another 2–3 weeks, which is longer than a normal shed. The gestation period, which is counted from the post ovulation shed, is approximately 100–120 days. The female will then give birth to young that average 15-20 inches (38–51 cm) in length. The litter
Litter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...

 size varies between females, but can be between 10 and 65 young with an average of 25, although some of the young may be still borns or non fertilised eggs known as "slugs". The young are independent at birth and will grow rapidly for the first few years, shedding regularly (once every one to two months). At between 3–4 years Boa constrictors become sexually mature and will have reached the adult size of between 6–10 ft, although they will continue to grow at a slow rate for the rest of their lives. At this point they will shed less frequently, approximately every 2–4 months.

Captivity

This species does well in captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...

, usually becoming quite tame. It is a common sight in both zoos and private reptile collections. Though still exported from their native South America in significant numbers, it is widely bred in captivity. When kept in captivity, they are fed mice, rats, rabbits, chickens and chicks depending on the size and age of the individual. Captive life expectancy
Life expectancy
Life expectancy is the expected number of years of life remaining at a given age. It is denoted by ex, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...

 is 20 to 30 years, with rare accounts of over 40 years, making them a long-term commitment as a pet. Proper animal husbandry is the most significant factor in captive lifespan, this includes providing adequate space, correct temperatures and humidity and suitable food items.

Young Boa constrictors should be started off in a relatively small enclosure, generally a secure plastic box or terrarium. This enclosure is then increased as the boa grows, as large open spaces are stressful for young snakes. Adults are often housed in vivariums, however large females may need even larger enclosures. The general rule is that the minimum length of the enclosure should be two thirds of the snake's length. Snakes are generally kept in separate enclosures, but people have successfully kept females together. Male boas should not be kept together as they may fight. Glass, aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

-style enclosures are seldom advised by snake keepers as they do not efficiently maintain temperature and humidity.

A thermal gradient should be provided, with a cool end and a warm end where the heat source should be located. The cool end should be maintained at 75–85°F (27–29°C), and the warm end at 86–92°F (30–33°C). Temperatures should not be allowed to rise above 95°F (35°C) or drop below 75°F (24°C). Cages that are too cold can cause many health problems, ranging from non-digestion of food to pneumonia
Pneumonia
Pneumonia is an inflammatory condition of the lung—especially affecting the microscopic air sacs —associated with fever, chest symptoms, and a lack of air space on a chest X-ray. Pneumonia is typically caused by an infection but there are a number of other causes...

. The necessary temperature can be provided by a heat mat, ceramic or specific light bulb or other alternative heating systems. All heat sources should be guarded, to prevent burns to the snake, and used in conjunction with a thermostat to prevent overheating. Humidity should be kept at 50%, and raised to 70% when the boa is in shed. However, high humidity should not be maintained for longer than a week, as this raises the risk of infections such as scale rot. Humidity levels can be maintained with a water bowl, and raised by adding more water bowls, moving the current water bowl closer to the heat source or misting the enclosure with a water sprayer. Boa constrictors do not need any special lighting, but should have approximately 12 hours of light and 12 hours of darkness every day to simulate a natural environment. Either a bulb or natural light can be used to provide such conditions.

Inside the enclosure a substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...

, generally of newspaper or aspen shavings, must be provided. Untreated cedar or pine shavings are to be avoided as they contain oils that are toxic to snakes. A water bowl, large enough to provide adequate humidity and that the boa can coil within, must be provided. Another basic essential is adequate hides, at least two (one in the cool end and one in the warm end). Hides can be anything from empty plastic or wooden boxes to specially made hides from a reptile equipment retailer. The hides ensure that the snake feels secure, as stress can result in snakes refusing to eat. Shelves or secure branches are often provided so that boas can climb, but this is not an essential. Fake plants and other natural looking decorations are also commonly provided, but again they are not essential.
Young boas can be started on small to medium mice and then on to increasing size of rats. Most boas will never need a prey item larger than a large rat, however some big females (8 ft+) may require rabbits, guinea pigs and chickens. The general rule for feeding snakes is that a suitable prey item is the girth of the snake at its widest point, as with most snakes (including Boa constrictor) the left and right sides of the lower jaw are joined only by a flexible ligament at the anterior tips, allowing them to separate widely, while the posterior end of the lower jaw bones articulate with a quadrate bone, allowing further mobility, to allow the consuming of large prey. Young snakes can be fed once a week, to promote healthy growth. Adults only need to be fed once every month. Overfeeding (or powerfeeding) the snake can lead to a host of health problems later and can shorten its lifespan. It is natural for snakes to lose their appetite when going into shed as this is a stressful time for them, as such food should not be offered at this time. Water should be changed daily or every other day.

Boas should be handled regularly to maintain their docility. However, large boas should be handled by two people, as these snakes are incredibly powerful. Snakes should never be handled within 48 hours of feeding, due to a risk of regurgitation, or when in a shed cycle.

Economic significance

Boa constrictors are very popular within the exotic pet trade, and have been both captured in the wild and also bred in captivity. Today most captive Boa constrictors are captive bred, however between 1977 and 1983 113,000 live Boa constrictors were imported into the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. These huge numbers of wild caught snakes have put considerable pressure on some wild populations. Boa constrictors have also been harvested for their meat and skins, and are a common sight at markets within their geographic range. After the reticulated python
Reticulated Python
Python reticulatus, also known as the reticulated python is a species of python found in Southeast Asia. Adults can grow to over 8.7 m in length but normally grow to an average of 3-6 m . They are the world's longest snakes and longest reptile, but are not the most heavily built...

 Boa constrictors are the snake most commonly killed for snake skin products, such as shoes, bags and other items of clothing. In some areas they have an important role in regulating the opossum populations, preventing the potential transmission of leishmaniasis
Leishmaniasis
Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly...

 to humans. In other areas they are often let loose within the communities to control the rodent populations.

Conservation

All Boa constrictors fall under CITES and are listed under CITES Appendix II, except B.c.occidentalis which is listed in CITES Appendix I.

In some regions Boa constrictor numbers have been severely hit by predation from humans and other animals, and over collection for the exotic and snake skin trades. However most populations are not under threat of immediate extinction, thus why they are within Appendix II rather than Appendix I.

Subspecies

There are 10 current subspecies of Boa constrictor, however much of these are poorly differentiated and it is thought that further research will redefine many of these subspecies. Some appear to be based more on location than biological differences, such as B. c. orophias (the St. Lucia Boa).
Subspecies Taxon author Common name Geographic range
B. c. amarali Stull
Olive Griffith Stull
Olive Griffith Stull was an American herpetologist.Stull was born February 10, 1905, in Rochester, New York. She married Loy Davis in 1930, one year after completing her degree at the University of Michigan. She worked in the field of veterinary medicine and contributed to research in a variety of...

, 1932
Amaral's boa Brazil, Bolivia and Paraguay
B. c. constrictor Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...

, 1758
Red-tailed boa South America
B. c. imperator
Boa constrictor imperator
Boa constrictor imperator is a nonvenomous boa subspecies found in Central America.-Description:B. c. imperator is wide-ranging, with animals living in both Central America and northern parts of South America...

Daudin
François Marie Daudin
François Marie Daudin was a French zoologist.With legs paralyzed by childhood disease, he studied of physics and natural history, but ended up being devoted to the latter.Daudin wrote in 1799–1800...

, 1803
Common northern boa Central America and northern South America
B. c. longicauda Price & Russo, 1991 Tumbes Peru boa Northern Peru
B. c. melanogaster Langhammer, 1983 Ecuadorian boa Ecuador
B. c. nebulosa (Lazell, 1964) Dominican clouded boa Dominica
B. c. occidentalis Philippi, 1873 Argentine boa Argentina and Paraguay
B. c. orophias Linnaeus, 1758 St. Lucia boa St. Lucia
B. c. ortonii Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...

, 1878
Orton's boa South America
B. c. sabogae (Barbour
Thomas Barbour
Thomas Barbour was an American herpetologist. From 1927 until 1946, he was director of the Museum of Comparative Zoology founded in 1859 by Louis Agassiz at Harvard University in Cambridge, Massachusetts....

, 1906)
Pearl Island boa "Pearl Islands" off the coast of Panama


There have also been several other subspecies described at different times, but currently these are no longer considered to be subspecies by many herpetologists and taxonomists. These include:
  • Boa constrictor mexicana (Jan 1863): This was described from a single specimen which had 55 dorsal scale rows, but otherwise appeared the same as a B. c. imperator. Since then B. c. mexicana has been included within the B. c. imperator subspecies by most authors, as Smith (1963) commented that no Mexican boas have been proven to have 55 dorsal scale rows. However, there is still controversy as Andrew (1937) reported four Mexican specimens with dorsal scale rows between 56-62.
  • Boa constrictor eques (Eydoux
    Joseph Fortuné Théodore Eydoux
    Joseph Fortuné Théodore Eydoux Joseph Fortuné Théodore Eydoux Joseph Fortuné Théodore Eydoux (1802 - 1841 was a French naturalist.Eydoux and Louis François Auguste Souleyet were surgeon naturalists on the expedition ship "La Favorite" which made a circumnavigation in 1830-32 captained by Cyrille...

     & Souleyet
    Louis François Auguste Souleyet
    Louis François Auguste Souleyet was a French zoologist, malacologist and naval surgeon.Souleyet was naturalist-surgeon on the voyage of La Bonite, which circumnavigated the globe between February 1836 and November 1837 under Auguste Nicolas Vaillant . In the Pacific he studied marine molluscs...

    , 1842): Based upon a single specimen from Peru that had one large orbital scale. However, no other such specimens have been found and it is thought that the snake was an aberrant B.c.imperator.
  • Boa constrictor diviniloqua (Duméril
    André Marie Constant Duméril
    André Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...

     & Bibron
    Gabriel Bibron
    Gabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...

    , 1844): Now known to be synonymous with B. c. orophias.
  • Boa constrictor sigma (Smith 1943): A very controversial possible subspecies from the Tres Marias Islands, Mexico. It appears like a B. c. imperator but has a higher number of ventral scales than B. c. imperator. It is possible a slightly different climate may have caused such a change, but this could then undermine the other insular subspecies such as B. c. orophias and B. c. nebulosa.
  • Boa constrictor isthmica (Garman 1883): Considered synonymous with B. c. imperator. It is from Panama.

Further reading

  • Stull OG. 1932. Five new subspecies of the family Boidae. Occasional Papers of the Boston Society of Natural History Vol. 8. p. 25-30. pl. 1-2. HTML version available at boa-subspecies.com. Accessed 20 February 2009.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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