North American boa constrictor (SciiFii)

The North American boa constrictor (Boa americanus), also known as the zebra-tailed boa, the zebra boa, and the northern boa, is a species of non-venomous snake of the family Boidae that originally did not exist, but has since been created by SciiFii and introduced throughout the rainforests, swamps, forests, and open woodlands across North America, as well as some islands in the Caribbean, to help boost biodiversity. The North American boa constrictor's color pattern is highly variable yet distinctive. Seventeen subspecies are currently recognized. The North American boa constrictor is a large snake, although it is only modestly sized in comparison to other large snakes, such as the reticulated python, Burmese python, or the green anaconda, and can reach lengths from 3–13 feet (0.91–3.96 meters) 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 feet (2.1 and 3.0 meters) whereas males are 6 and 8 feet (1.8 and 2.4 meters). Females commonly exceed 10 feet (3.0 meters), particularly in captivity, where lengths up to 12 feet (3.7 meters) or even 14 feet (4.3 meters) can be seen. The largest known specimens can measure a little more than 14.6 feet (4.45 meters) in length. North American boa constrictors generally live on their own and do not interact with any other snakes unless they want to mate. They are nocturnal, but they may bask during the day when night-time temperatures are too low. As semi-arboreal snakes, young North American boa constrictors may climb into trees and shrubs to forage; however, they become mostly terrestrial as they become older and heavier. North American boa constrictors strike when they perceive a threat. Their bite can be painful, especially from large snakes, but the dangers of North American boa constrictors' bites on humans is extremely rare, even more rarely than their South American relatives. Specimens from southeastern United States are more irascible, hissing loudly and striking repeatedly when disturbed, while those from western and southwestern United States tame down more readily. Like all snakes, North American boa constrictors 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 otherwise be. Their prey includes a wide variety of small to medium-sized mammals and birds. The bulk of their diet consists of rodents, but larger lizards and mammals as big as ocelots are also consumed. Young North American boa constrictors eat small mice, birds, bats, lizards, and amphibians. The size of the prey item increases as they get older and larger. North American boa constrictors are ambush predators, so they often lie in wait for an appropriate prey to come along, then they attack. However, they have also been known to actively hunt, particularly in regions with a low concentration of suitable prey, and this behavior generally occurs at night. The boa first strikes at the prey, grabbing it with its teeth; it then proceeds to constrict the prey until death before consuming it whole. Unconsciousness and death likely result from shutting off vital blood flow to the heart and brain, rather than suffocation; constriction can interfere with blood flow and overwhelm the prey's usual blood pressure and circulation. This would lead to unconsciousness and death very quickly. Their teeth also help force the animal down the throat while muscles then move it toward the stomach. It takes the snake about 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 a week to several months, due to its usually slow metabolism. Like other boas, North American boa constrictors are ovoviviparous, giving birth to live young. They generally breed in spring and summer, between April and August, and are polygynous; thus, males may mate with multiple females. Unlike other boas, the North American boa constrictors have antifreeze in their blood to protect them against very cold temperatures while also not affecting their ability to tolerate heat, allowing them to be active year-round and allowing their species to live in almost every known forest-type habitat of North America. Uniquely among boas and other snakes, the North American boa constrictor displays endothermy (warm-bloodedness), however, this only occurs during the breeding seasons and when the female has developing young inside her just before the young leave their mother's abdomen. The conservation status of the North American boa constrictor is Least Concern due to successful conservation efforts, the North American boa constrictor's wide range and its tolerance to many of the human activities.