Boa

Boas are some of the largest snakes in the world. They weigh over 100 pounds (45 kilograms) and their maximum length is over 4 meters. Boas are found in deserts, tropical forests, savannas and small tropical islands, and are native to Mexico, Central America, Colombia, Ecuador, and northern Peru, and have become invasive in other regions like Puerto Rico. They usually make homes in agricultural areas, deserts, natural forests, planted forests, ranges, grasslands and shrublands. They capture and eat small mammals through the process of "constriction" - grabbing and holding prey while they wrap their muscular bodies around their victim, squeezing until they suffocates.

Body Design
Boa constrictors have modest-sized boids. The maximum length is over 4 meters and individuals are between 2 and 3 meters. They weigh more than 100 pounds (45 kilograms). Females are usually larger than males, however, the tails of males are longer than females because of the space taken up by the hemipenes (a pair of organs used to deliver sperm during copulation) ) Boa constrictor coloration and pattern are distinctive. They match the habitat where they live so they can blend in. They can be tan, yellow, red, pinkish or green in color, but they are usually tan with a dark-brown color. The head of a boa constrictor has 3 distinctive stripes. First is a line that runs dorsally from the snout to the back of the head. Second is a dark triangle between the snout and the eye. Third is a dark triangle that continues behind the eye.

Boa constrictor jaws are lined with small, hooked teeth for grabbing and holding prey while they wrap their muscular bodies around their victim, squeezing until they suffocates. The patterns on their bodies can be jagged lines, ovals, diamond shapes, or circles. Boa constrictors have 57-72 dorsal scales(The scales that are located on longitudinal series of plates that encircle the body ) rows with dark brown areas on the tail. Orbital scales are between 16 to 18 and 14 small scales cross the forehead from eye to eye. There is no loreal scale(The scale located between the eyes and nostrils. ) but there are 9 to 10 tiny scales between the nostril and the eye. Boa constrictors have heat receptors(A nerve ending that senses changes in light, temperature, pressure and causes the body to react in a particular way. ) that are used for detection of warm-blooded prey. Boa uses its sense of smell to find its victims. This is located on the tongue.

Life Cycle


Boa Constrictors can live as long as 30 years and the female can produce as many as 60 newborns. They are independent from the time of birth to death. Fertilization is internal and development is ovoviviparous, which means the egg supporting the young remains inside the mother's body after it is fertilized. The embryo receives it's nutrients from the yolk, which is a membranous sac. After a period of about 4 months, the fully developed egg will hatch inside the mother's body and she will give birth to live offspring. The babies separate from the parent almost immediately and begin a life on their own.

Boa constrictors do not have any type of metamorphosis. Their skin does not grow, which results in the process of shedding. To do so, beneath the previous layer of skin, a fresh one must be created. A coat of liquid will then form, allowing an escape from the mold. Often times a boa will imperceptibly change its color as it grows, but that is the only change in appearance it will undergo.

Ecology
Invasive boas are often found in habitats such as deserts, tropical forests, savannahs, and small tropical islands. They are native to Mexico, Central America, Colombia, Ecuador, and northern Peru. They also frequent The Caribbean islands of Belize, Cozumel, Puerto Rico and the Virgin Islands. They have been known to live in cities and cultivated areas, where human development has forced them to adapt, but they usually stay in their natural environment when possible. Boas tend to make homes in environments such as agricultural areas, deserts, natural forests, planted forests, ranges, grasslands and shrublands.

Boas often feed on large lizards, small-sized birds, opossums, bats, mongooses, rats, and squirrels. Bats are their preferred prey which they catch by hanging on tree branches and cave mouths, and grabbing them from the air. They are nocturnal hunters and often use heat-sensitive scales to locate their prey. Boas love the water and they will often be found swimming. They are also able to find lots of quality prey around those areas. They live their lives alone other than when they meet up for mating.

Invasive Species
Location and Method of Introduction

Boa's are a major problem in Puerto Rico, an island they are not originally from. Exotic boa constrictors are thought to have been accidentally released into Mayaguez, an area on the western side of Puerto Rico, during the early 1990s. They have been found to have spread out from Mayaguez since the time of their time of their release and scientists caught 37 boas just along highways and around the city. We now know that boas have since spread all throughout the island into the native jungles and tropical forests. Environmental Impact

Boa can colonize new areas relatively quickly and compete with native species for food and shelter. Also they may carry new diseases such as the fatal Inclusion Body Disease which has been shown to be transferred from boa constrictors to native Australian pythons in captivity.

Control Methods

Scientists fear the rapid multiplication of boa constrictors on the island of Puerto Rico and are urging citizens to help keep the population under control. Scientists, through DNA analysis, are working on pinpointing the origin spot of the boa. They are trying to figure out where they are coming from so they stop the spreading and apprehend whoever is releasing them. From this research they have found that most have been released on roadways either accidentally or on purpose. However, because they have a limited environmental impact they do not propose an immediate threat.

Video
Video of Boa constrictor shedding. EXH-1qi7Xp8