Boa constrictor

The boa constrictor (Boa constrictor), also called the red-tailed boa or 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 Boidae, found in tropical North, Central, and South America, as well as some islands in the Caribbean. A staple of private collections and public displays, its color pattern is highly variable yet distinctive. Nine subspecies are currently recognized, although some of these are controversial. This article focuses on the species Boa constrictor as a whole, and on the nominate subspecies B. c. constrictor. Though all boids are constrictors, only this species is properly referred to as a 'boa constrictor' – a rare instance of an animal having the same common English name and scientific binomial name. 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 species such as B. imperator, which is also regularly, and erroneously, referred to as a 'red-tailed boa' or 'common boa'. Other common names include chij-chan (Mayan), jiboia (Latin American), and macajuel (Trinidadian). The boa constrictor is a large snake, although it is only modestly sized in comparison to other large snakes, such as the reticulated python and Burmese python, and can reach lengths from 3–13 ft (0.91–3.96 m) depending on the locality and the availability of suitable prey. Clear sexual dimorphism is seen in the species, with females generally being larger in both length and girth than males. The usual size of mature female boas is between 7 and 10 ft (2.1 and 3.0 m) whereas males are 6 and 8 ft (1.8 and 2.4 m). Females commonly exceed 10 ft (3.0 m), particularly in captivity, where lengths up to 12 ft (3.7 m) or even 14 ft (4.3 m) can be seen. The largest documented non-stretched dry skin is deposited at Zoologische Staatssammlung München (ZSM 4961/2012) and measures 14.6 ft (4.45 m) without head. A report of a boa constrictor growing up to 18.5 ft (5.6 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 (60 lb). Females, the larger sex, more commonly weigh 10 to 15 kg (22 to 33 lb). Some specimens of this species can reach or possibly exceed 45 kg (100 lb), although this is not usual. The size and weight of a boa constrictor depends on subspecies, locale, and the availability of suitable prey. B. c. constrictor 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 males generally having 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.