''Boa imperator'' (or ''Boa constrictor imperator'' in common usage) is a large and heavy-bodied

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of nonvenomous, constrictor-type snake in the family

Boidae The Boidae, commonly known as boas or boids, are a family of nonvenomous snakes primarily found in the Americas, as well as Africa, Europe, Asia, and some Pacific islands. Boas include some of the world's largest snakes, with the green anaconda ...

. One of the most popular pet

snakes Snakes are elongated Limbless vertebrate, limbless reptiles of the suborder Serpentes (). Cladistically Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales much like other members of ...

(often bred in captivity) in the world, ''B. imperator'''s native range is from

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

through Central and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

(west of the

Andes Mountains The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

, mainly in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

), with local populations on several small

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

islands. It is commonly called the Central American boa, northern boa, Colombian boa (or Colombian red-tailed boa), common boa and common northern boa.

Description

''Boa imperator'' is a wide-ranging species, living in both Central America and the northern parts of South America. As a result, the appearance of this snake varies greatly depending on the specific locality. As one of the smaller '' Boa'' species,Cotswold Wildlife Park and Gardens
they average between 1.3 m (4.2 ft.) and 2.5 m (8.2 ft.) in length when fully grown, but have been known to reach 3.7 m (12 ft.). They usually weigh around 6 kg (13 lb), although females are significantly larger than males. Lifespan in the wild is around 20–30 years, but 40 can be exceeded in captivity. Although ''Boa imperator'' exhibits almost identical patterns to ''

Boa constrictor The boa constrictor (scientific name also ''Boa constrictor''), also known as the common boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the Family (b ...

'', this species often has a darker tail, usually dark brown or very dark red. They are, however, usually just as colorful as their counterparts and, like the larger boas, can be bred into a variety of different colors, given the right conditions to breed. Notably, the species is one of only two in snakes to have a confirmed XY sex chromosome system. One population, found on the Cayos Cochinos (Hog Islands) off the northern coast of

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

, have evolved naturally hypomelanistic skin (containing reduced

melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

), resulting in lighter-colored snakes; nonetheless, they retain the "signature" darkened tail-tip seen in the species, though the color of the tail may vary from salmon-pink to orange. Nic Boa

Another well-known locality of ''Boa imperator'' is the population from

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

, which typically have a compact saddle-pattern on their backs, often showing circular and spherical shapes. Boas from

can be among the largest boas as well as some of the smallest; this species includes a number of dwarf insular populations on several

Caribbean islands Most of the Caribbean countries are islands in the Caribbean Sea, with only a few in inland lakes. The largest islands include Cuba, Hispaniola, Jamaica and Puerto Rico. Some of the smaller islands are referred to as a ''rock'' or ''reef.'' ''I ...

. Off the Pacific coast of Colombia, smaller to medium-sized boas can be found living on Gorgona Island, a former Colombian prison colony that nature has reclaimed, with a high rate of

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

present on the island.

Scalation

''Boa imperator'' has 55–79 dorsal scales, 225–253 ventral scales, 47–69 subcaudal scales, 18–22 supralabial scales and 1–2 anal scales.

Identification

''Boa imperator'' is commonly confused with other ''Boa'' species, such as ''Boa constrictor''. Both have very similar patterns, to include a reddening of the lighter colors towards a deeper or darker red on the tail. This has resulted in a non-scientific term - "red-tailed boa" - used to refer to both species (mostly in the pet trade).

Taxonomy

''Boa imperator'' was formerly classified as a subspecies of ''Boa constrictor'' until DNA sequencing identified ''B. c. imperator'' as a separate genetic lineage with 5-7% divergence from ''B. constrictor''. The boa population from the Pacific Coast of Mexico, previously considered a subspecies of ''B. constrictor'' and subsequently of ''B. imperator'', has been separated as another species, ''

Boa sigma ''Boa sigma'', known commonly as the Mexican west coast boa constrictor, is a species of snake in the family Boidae. The species is endemic to western Mexico. ''Boa sigma'' has previously been regarded as conspecific with ''Boa constrictor'', and ...

''.

Subspecies

Certain ''Boa imperator'' populations such as the ones in the Cayos Cochinos (or the Hog Islands) off the northern coast of

; the

Corn Islands The Corn Islands are two islands about east of the Caribbean Sea, Caribbean coast of Nicaragua, constituting one of 12 Municipality, municipalities of the South Caribbean Coast Autonomous Region of Nicaragua. The official name of the municipalit ...

off the eastern coast of

; the Tarahumara Mountains in Mexico;

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

; etc. are classified as different "locales" of ''Boa imperator'', but not as subspecies.

Geographic range

''Boa imperator'' can be found in some regions of

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

and northwestern

, as well as several islands along the coasts of these areas. The type locality given is "l'Amerique meridionale, principalement au Mexique" (Central America, principally Mexico). ''Boa imperator'' prefers to live in

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

s due to humidity, temperature, cover from potential predators and ample prey.

Behavior

''Boa imperator'' generally live on their own, and do not interact with any other snakes unless they want to mate. They are

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...

, but they may bask during the day when night-time temperatures are too low. As semi-arboreal snakes, young ''Boa imperator'' may climb into trees and shrubs to forage; however, they become mostly terrestrial as they become older and heavier.Mehrtens JM. 1987. ''Living Snakes of the World in Color''. New York: Sterling Publishers. . ''Boa imperator''s strike when they perceive a threat. Their bite can be painful, especially from large snakes, but is rarely dangerous to humans. Specimens from Central America are more irascible, hissing loudly and striking repeatedly when disturbed, while those from South America tame down more readily.Stidworthy J. 1974. ''Snakes of the World''. Grosset & Dunlap Inc. . Like all snakes, ''Boa imperator''s in a shed cycle are more unpredictable, because the substance that lubricates between the old skin and the new makes their eyes appear milky, blue or opaque, so that the snake cannot see very well, causing it to be more defensive than it might be otherwise.

Hunting and diet

Central American Boa imported from iNaturalist photo 129121475 on 3 December 2024

''Boa imperator'', like most ''Boa'' species, has a varied diet that consists mainly of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s (such as

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...

agouti The agouti (, ) or common agouti is any of several rodent species of the genus ''Dasyprocta''. They are native to Central America, northern and central South America, and the southern Lesser Antilles. Some species have also been introduced else ...

coati Coatis (from Tupí), also known as coatimundis (), are members of the family Procyonidae in the genera '' Nasua'' and '' Nasuella'' (comprising the subtribe Nasuina). They are diurnal mammals native to South America, Central America, Mexico, ...

ocelot The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...

fox Foxes are small-to-medium-sized omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull; upright, triangular ears; a pointed, slightly upturned snout; and a long, bushy tail ("brush"). Twelve species ...

es, tree porcupines, young

deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes. Thus monkeys, in that sense, co ...

s, and

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s),

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s and

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s (such as ''

Iguana iguana The green iguana (''Iguana iguana''), also known as the American iguana or the common green iguana, is a large, arboreal, mostly herbivorous species of lizard of the genus ''Iguana''. Usually, this animal is simply called the iguana. The green ...

'' and '' Medopheos edracanthus''). Bats are ambushed on trees, at the entrance of caves, or in abandoned houses. Domestic animals, such as

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s and

cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s, are frequently consumed. The size of the prey item increases as it ages. ''Boa imperator'', like other ''Boa'' species, are crepuscular ambush predators. They use constriction as the primary means of incapacitating their prey.

Captivity

''Boa imperator'' is one of the most common snakes kept in captivity; this is mainly due to their calm dispositions, impressive size potential and variety of color and pattern choices. Captive common boas also often tolerate being handled for extended periods.Reptiles Magazine Boa Care sheet
/ref> Captive ''B. imperator'' are generally fed frozen, thawed, pre-killed

rodents Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

or chicks—depending on the size of the snake in question—in an effort to avoid exposing the snake to potential injury or infection from a live prey animal. While some handlers and keepers may prefer to offer live prey, under careful supervision, any live rodent or bird could potentially fight-back and injure the snake, if not subdued quickly. Furthermore, live prey, rather than frozen, carries the risk of internal parasites being transferred to the snake upon digestion. In addition to these health and safety concerns, frozen and thawed prey is also considered to be more ethical and humane for the prey animal itself. This snake species has been a common species in the global pet trade since the 1980s, with 115,131 individuals being exported between 1989 and 2000. Global Invasive Species Database (GISD) 2015. Species profile ''Boa constrictor imperator''. Available from: http://www.iucngisd.org/gisd/species.php?sc=1439 ccessed 23 October 2018/ref> Wild-caught specimens are often illegally captured and highly stressed, as they are unceremoniously packed into shipping containers with other snakes—and sometimes other species of reptiles. Many individuals simply perish in-transit from the stress of being in a confined space with other snakes after being captured; survivors will often arrive in North America, Europe, and other markets infested with wild parasites, both internal and external. The most common parasite is '' Ophionyssus natricis'', or the "reptile mite", in addition to

ticks Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

and parasitic

worms The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

. However, with decades of captive and selective breeding having been undertaken globally, hand-reared and healthy snakes are widely available (and superior specimens in many ways), thus reducing the strain on wild populations. In addition to breeding for temperament, sociability and health, ''Boa imperator'' breeders will also often breed for a specific color pattern, or "morph", based on unique genetic expressions. There are many unique color and pattern morphs available in the pet trade, such as

albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...

, hypomelanistic, motley and jungle individuals.

Notes

References

External links

* {{Taxonbar, from=Q58741252, from2=Q3626797

imperator The title of ''imperator'' ( ) originally meant the rough equivalent of ''commander'' under the Roman Republic. Later, it became a part of the titulature of the Roman Emperors as their praenomen. The Roman emperors generally based their autho ...

Snakes of Central America Reptiles of Guatemala Reptiles of Mexico Reptiles of Panama Reptiles described in 1803 Taxa named by François Marie Daudin