Boa constrictor occidentalis

Last updated

Boa constrictor occidentalis
Boa constrictor occidentalis (2).JPG
CITES Appendix I (CITES) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Boidae
Genus: Boa
Species:
Subspecies:
B. c. occidentalis
Trinomial name
Boa constrictor occidentalis
Philippi, 1873

Boa constrictor occidentalis, also commonly known as the Argentine boa, is a subspecies of large, heavy-bodied, nonvenomous, constricting snake. [2] Boa constrictor occidentalis is a member of the family Boidae, found mostly in tropical and subtropical areas in northern Argentina and Paraguay, although some members have been reported to exist in Bolivia as well. [3]

Contents

Description

Size and weight

Skeleton of Boa constrictor occidentalis Skeleton of Boa constrictor occidentalis.jpg
Skeleton of Boa constrictor occidentalis

The Boa constrictor occidentalis subspecies experiences sexual dimorphism, with females being greater in size and weight. Adult males reach anywhere between 6 and 8 feet. [4] Whereas adult females can reach lengths of 8 to 10 feet regularly, though some members have been found to reach as long as 4 m (13.13 ft).

Male members of this subspecies on average weigh 4.06 kg (8.95 lb). Female members are much heavier, weighing at an average of 6.13 kg (13.5 lb). [2]

Male Argentine boas generally have longer tails in order to contain the hemipenes as well as having longer pelvic spurs that the male uses to grip onto the female and stimulate during copulation.

Coloring

Boa constrictor occidentalis possess a wide range of scale coloration ranging from black specimens with a high rate of contrasting white to specimens exhibiting varying degrees of burnt-orange to red. [5] This species usually possesses a grey belly and a dark line running from the neck to the tip of its snout, as well as from the eyes to the neck. Young members of this species commonly exhibit a pink hue that darkens as they reach sexual maturity. [6]

Scalation

Boa constrictor occidentalis possesses 242-251 ventral scales, 64-87 dorsal scales, 21-22 supralabial scales, and 45 subcaudal scales. [7]

Distribution and habitat

Boa constrictor occidentalis is an exclusively New World subspecies, found in Argentina. Predominantly, it has been observed between the Andes Mountains and the Parana River in Paraguay, and reportedly in Bolivia. [5] [8] It is endemic in the Gran Chaco region. [9] It has the largest distribution of all neotropical boas. [8] Boa constrictor occidentalis can be found in 13 of the 23 provinces of Argentina and has been estimated to have a historical extent of occurrence that covers approximately 15% of the country's mainland territory, which is about 42.3 million ha. Its southernmost limit of distribution in South America rests at 33° 20' S latitude, in the province of San Luis, Argentina. [10]

Boa constrictor occidentalis prefers wetland habitat, such as rainforest, floodplains, or flooded forest, due to the high humidity and moderate temperatures. Boa constrictor occidentalis prefers temperatures of 80-85 degrees Fahrenheit with nighttime temperatures of 78 degrees, though they are capable of tolerating temperatures down to 65-70 degrees Fahrenheit. This subspecies commonly associates with Viscacha (Lagostomus maximus) burrows, preying on the rodents and using their burrows as refuge. Though mostly terrestrial, this subspecies will sometimes live on and around trees that they climb for hunting and perching. During the day, it will shelter within tree hollows, old logs and, as previously mentioned, animal burrows. The snakes can occasionally be seen basking in the sun, coiled on tree branches directly over water. [11] [12] Boas can persist in environments that have been degraded, so long as woody plants and scattered trees are present to meet the subspecies' needs.

The habitat that Boa constrictor occidentalis resides in reaches an altitude of 900–1,000 meters above sea level, with rainfall of 250–900 mm. Though very rare, it has been reportedly found at elevations above 1,000 meters, and in areas with rainfall in excess of 900 mm. [10]

Behavior

Boa constrictor occidentalis are nocturnal and are usually independent, not interacting with other members of its subspecies except during mating seasons. They are known to be a very docile but can become very aggressive when it becomes frightened or nervous, and are known to hiss during these situations. Boa constrictor occidentalis enjoy soaking in water and as such live in wetlands and near bodies of water such as streams, ponds, rivers, etc.

Hunting and diet

Boa constrictor occidentalis is an opportunistic hunter, feeding on small animals, birds, and rodents. This subspecies is very active at night, climbing on trees to ambush prey. As per its species, the Boa constrictor occidentalis kills prey by constriction. It ambushes prey, grasping the prey using its mouth and large teeth, proceeding to wrap its coils around the body of the prey, exerting high amounts of external pressure that stop blood flow to the brain, quickly killing the prey. [11]

Reproduction and development

Boa constrictor occidentalis reproduction is strongly seasonal within both sexes. Females are reproductive between April and August during the dry season. During this dry season 50% of adult females and 64% of adult male are reproductive. Boa constrictor occidentalis undergo mating aggregations during the dry seasons for reproduction usually consisting of one adult female and one to three adult males. [2] Clutches range between ten and forty live young and average around 25 live young. Boa constrictor occidentalis is ovoviviparous. Gestation periods last between 5 and 8 months and is dependent on the environmental temperature. They are born fully independent and experience little change in coloration as they develop, with the only major change being a fading of color. Young boas tend to be arboreal in nature, but as they grow larger and heavier, they become more terrestrial. Boa constrictor occidentalis reach sexual maturity around 2–3 years. Young Boa constrictor occidentalis will shed their skin up to 9 times a year if intensely fed. As the subspecies reaches sexual maturity, this shedding process slows down to four to five sheds per year. [3]

Captivity

Boa constrictor occidentalis is a common subspecies found in the pet trade. Due to their status as a threatened subspecies on the CITES Appendix I, heavy restrictions have been implemented on the exporting of Argentine boas. While in captivity, life expectancy of an Argentine boa ranges between 20 and 30 years, some have been known to live longer - up to 40 years. When in captivity, Argentine boas are fed mice, rats, rabbits, and even small birds.

Conservation

Boa constrictor occidentalis is considered a threatened subspecies. Boa constrictor occidentalis is incapable of occupying grass- or crop-dominated landscapes without there being a more complex spatial matrix that includes patches of woody vegetation. [10] The species is subject to strong hunting and capture pressures for both its skin and for the pet trade. Intense farming and cattle raising has severely modified its habitat. [2] Because of these environmental pressures over the past 90 years, its original range has been severely reduced to only a fraction of what it was originally.

Boa constrictor occidentalis is the only Boa constrictor subspecies listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This means commercial international trade in the species or its parts/derivatives is prohibited. [3]

Related Research Articles

<span class="mw-page-title-main">Boidae</span> Family of snakes

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 of South America being the heaviest and second-longest snake known; in general, adults are medium to large in size, with females usually larger than the males. Six subfamilies comprising 15 genera and 54 species are currently recognized.

<span class="mw-page-title-main">Ball python</span> Species of constricting snake

The ball python, also called the royal python, is a python species native to West and Central Africa, where it lives in grasslands, shrublands and open forests. This nonvenomous constrictor is the smallest of the African pythons, growing to a maximum length of 182 cm (72 in). The name "ball python" refers to its tendency to curl into a ball when stressed or frightened.

<span class="mw-page-title-main">Slender glass lizard</span> Species of reptile

The slender glass lizard is a legless lizard in the glass lizard subfamily (Anguinae). The species is endemic to the United States. Two subspecies are recognized. The lizard was originally believed to be a subspecies of the eastern glass lizard. Their name comes from their easily broken tail which they can break off themselves without ever being touched. It is difficult to find a specimen with an undamaged tail. The lizard eats a variety of insects and small animals, including smaller lizards. Snakes and other animals are known to prey on the species. Humans have a part in destroying their environment and killing their food supply with insecticides. The lizard is considered to be a least-concern species according to the International Union for Conservation of Nature (IUCN), though it is vulnerable in Iowa and endangered in Wisconsin. It is important to note that the streamlined, legless species is often confused with snakes. Glass Lizards, however, differ from snakes as they possess a moveable eyelid, which is absent in snakes. Another way to distinguish glass lizards from snakes is the presence of an external ear opening, which are absent in snakes.

<i>Loxocemus</i> Genus of snakes

Loxocemus bicolor, the sole member of the monotypic family Loxocemidae and commonly known as the Mexican python, Mexican burrowing python and Mexican burrowing snake, is a species of python-like snake found in Mexico and Central America. No subspecies are currently recognized. Analyses of DNA show that Loxocemus is most closely related to the true pythons and the sunbeam snakes.

<span class="mw-page-title-main">Green anaconda</span> Species of snake

The green anaconda, also known as the giant anaconda, emerald anaconda, common anaconda, common water boa, or southern green anaconda, is a boa species found in South America and the Caribbean island of Trinidad. It is the largest, heaviest and the second longest snake in the world, after the reticulated python. No subspecies are currently recognized. Like all boas, it is a non-venomous constrictor.

<i>Corallus hortulana</i> Species of snake

Corallus hortulana, previously known as Corallus hortulanus, and commonly known as the Amazon tree boa, common tree boa, garden tree boa, and macabrel, is a boa species found in South America. Previously, there were two recognized subspecies, Corallus hortulanus hortulanus, and Corallus hortulanus cooki, though the species has undergone taxonomic revision and has been broken up into several species. It is primarily nocturnal and arboreal, though it has been observed feeding and reproducing on the ground. Like all boas, it is non-venomous.

<i>Elaphe</i> Genus of rat snakes

Elaphe is a genus of snakes in the family Colubridae. Elaphe is one of the main genera of the rat snakes, which are found in many regions of the northern hemisphere. Elaphe species are medium to large constrictors by nature.

<span class="mw-page-title-main">Eastern racer</span> Species of snake

The eastern racer, or North American racer, is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America and Central America. Eleven subspecies, including the nominotypical subspecies, are recognized, which as a group are commonly referred to as the eastern racers. The species is monotypic in the genus Coluber.

<i>Opheodrys aestivus</i> Species of snake

Opheodrys aestivus, commonly known as the rough green snake, is a nonvenomous North American colubrid. It is sometimes called grass snake or green grass snake, but these names are more commonly applied to the smooth green snake. The European colubrid called grass snake is not closely related. The rough green snake is docile, often allowing close approach by humans, and seldom bites. Even when bites occur, they have no venom and are harmless.

<span class="mw-page-title-main">Argentine black and white tegu</span> Species of lizard which is the largest of the tegu lizards

The Argentine black and white tegu, also known as the Argentine giant tegu, the black and white tegu, or the huge tegu, is a species of lizard in the family Teiidae. The species is the largest of the "tegu lizards". It is an omnivorous species which inhabits the tropical rain forests, savannas and semi-deserts of eastern and central South America.

<span class="mw-page-title-main">Cuvier's dwarf caiman</span> Species of reptile

Cuvier's dwarf caiman is a small crocodilian in the alligator family from northern and central South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Venezuela. It lives in riverine forests, flooded forests near lakes, and near fast-flowing rivers and streams. It can traverse dry land to reach temporary pools and tolerates colder water than other species of caimans. Other common names for this species include the musky caiman, the dwarf caiman, Cuvier's caiman, and the smooth-fronted caiman. It is sometimes kept in captivity as a pet and may be referred to as the wedge-head caiman by the pet trade community.

<i>Thamnophis saurita saurita</i> Subspecies of snake

Thamnophis saurita saurita, the eastern ribbon snake or common ribbon snake, is one of four subspecies of the ribbon snake found in the southeastern United States.

<span class="mw-page-title-main">Cuban boa</span> Species of snake

The Cuban boa, also known as the Cuban tree boa and by locals as majá de Santa María, is a very large species of snake in the family Boidae. With lengths exceeding 5 m (16 ft) and a relatively heavy build, the Cuban boa is one of the largest snakes in the world. The species is native to Cuba and some nearby islands. No subspecies are currently recognized.

<i>Boa imperator</i> Species of snake

Boa imperator is a large and heavy-bodied arboreal species of non-venomous, constrictor-type snake in the family Boidae. One of the most popular pet snakes in the world, B. imperator's native range is from Mexico through Central and South America, with local populations on several small Caribbean islands. It is commonly called the Central American boa, northern boa, Colombian boa, common boa and common northern boa.

<i>Epicrates maurus</i> Species of snake

Epicrates maurus is a species of non-venomous constrictor in the family Boidae, commonly found in the Amazon region of South America. The common name for this species is the brown rainbow boa. This species is semi-arboreal, spending time both on the ground and climbing trees and shrubs, although they are also known to swim. They are nocturnal and primarily active in the middle of the night. Rainbow boas are known for their attractive iridescent sheen on their scales in the sunlight.

<span class="mw-page-title-main">Southern rubber boa</span> Species of snake

Charina umbratica, known commonly as the southern rubber boa, is a species of snake in the family Boidae. The species is endemic to the United States, in southern California.

<span class="mw-page-title-main">Boa constrictor</span> Species of snake

The 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 Boidae. The species is native to tropical South America. A staple of private collections and public displays, its color pattern is highly variable yet distinctive. Four subspecies are recognized.

<i>Pantherophis alleghaniensis</i> Species of snake

Pantherophis alleghaniensis, commonly called the eastern rat snake, is a species of nonvenomous snake in the family Colubridae. The species is endemic to North America.

<i>Masticophis flagellum flagellum</i> Subspecies of snake

Masticophis flagellum flagellum, commonly known as the Eastern coachwhip, is a subspecies of M. flagellum, a nonvenomous, colubrid snake, endemic to the southern United States.

<i>Chironius flavolineatus</i> Species of vine snake

Chironius flavolineatus, also known as Boettger's sipo, is a vine snake species in the family Colubridae, endemic to savannas and semiarboreal biomes in Brazil, and much of South America. It is listed as least concern on the IUCN Red List since 2014. It is a member of the Genus Chironius which is composed of twenty-two other described snake species. It is nonvenomous, using camouflage or burrowing as a form of defense.

References

  1. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  2. 1 2 3 4 Bertona, Miguel; Chiaraviglio, Margarita (September 2003). "Reproductive Biology, Mating Aggregations, and Sexual Dimorphism of the Argentine Boa Constrictor (Boa constrictor occidentalis)". Journal of Herpetology. 37 (3): 510–516. doi:10.1670/122-02a. ISSN   0022-1511. S2CID   55876805.
  3. 1 2 3 "Home". Stöckl - Die Nr.1 Boa constrictor Seite im Internet (in German). Retrieved 2019-11-17.
  4. "Argentine Boa". Reptile Range. Retrieved 11 August 2022.
  5. 1 2 "Reptiles Magazine, your source for reptile and herp care, breeding, and enthusiast articles". www.reptilesmagazine.com. Retrieved 2019-11-17.
  6. "#1 Snake Encyclopedia & Snake Shop". SnakeEstate. Retrieved 2019-11-17.
  7. Lotte, Jose. "Taxonomy and Determination of Boa Constrictor" (PDF). Litteratura Serpentium: 78–81.
  8. 1 2 Lindemann, Laurel. "Boa constrictor (Boa Constrictor)". Animal Diversity Web. Retrieved 2019-11-17.
  9. Cardozo, Gabriela; Chiaraviglio, Margarita (1 December 2008). "Landscape changes influence the reproductive behaviour of a key 'capital breeder' snake (Boa constrictor occidentalis) in the Gran Chaco region, Argentina". Biological Conservation. 141 (12): 3050–3058. doi:10.1016/j.biocon.2008.08.026.
  10. 1 2 3 Waller, Tomas; Micucci, Patricio; Barros, Mariano; Draque, Juan; Estavillo, Candelaria (2012-01-01). "Conservation Status of the Argentine Boa Constrictor (Boa constrictor occidentalis) 20 Years After Being Listed in CITES Appendix I". IRCF Reptiles and Amphibian Conservation. 19: 1–10. doi: 10.17161/randa.v19i1.13830 .
  11. 1 2 "boa constrictor | Description, Size, Subspecies, & Facts". Encyclopedia Britannica. Retrieved 2019-11-17.
  12. Eastwick, Richard (28 July 2013). "Boa in the Boat". www.Youtube.com. Retrieved 13 February 2023.