Bothriopsis punctata

Bothriopsis punctata, commonly known as the Chocoan forest pit viper or the Chocoan lancehead, has a very small geographic range in northwest South America. This species ranges from the Darien gap in Panama, through Colombia and Ecuador, to northern Peru. Chocoan forest pit vipers are thought to have originated in Colombia.

Pit vipers in the genus Bothriopsis typically inhabit rainforests and moist swamplands. Chocoan forest pit vipers are are found in tropical, supbropical, and montane moist rainforests in the Chocoan rainforests, the Andes Mountains, and the Darien Gap swamplands. They prefer undeveloped land with minimal disturbances. Chocoan forest pit vipers inhabit relatively lower altitudes than other species in the genus, and can be found up to 2300 m in elevation. They are generally found in shrubs, trees, or bushes or on the ground, though they are also thought to be semi-arboreal.

Chocoan forest pit vipers are usually pale brown or greenish tan in color. They have 16 to 22 pairs of paravertebral blotches that are brown in color with pale edges and can combine dorsally. Below these blotches, another layer of dark spots alternate with lighter spots, giving the body a semibanded look. Chocoan forest pit vipers have a dark brown cheek stripe that is darkest at the outer edges and is bordered with a lighter color. This border is usually a light orange or yellow.

Pit vipers are named for the heat-sensing pit organs located between their nose and eyes. These pit organs aid in finding endothermic prey. Chocoan forest pit vipers have triangular shaped heads, hence the common name "lancehead." They have solenglyphous fangs, which refers to the hollow and long fangs at the front of their mouth. The fangs are connected to an elongate ectopterygoid bone, which serves as a hinge for the fangs. When they open their mouth, the fangs come forward ready to sink into their prey. Fangs are retracted when they close their mouth. The large solenglyphous fangs carry the venom from the venom glands.

Chocoan forest pit vipers have heavily keeled scales. Males and females have 25 to 29 rows of dorsal scales. This species demonstrates sexual dimorphism in number of ventral scales and paired subcaudal scales. Males generally have 186 to 211 ventral scales and 70 to 95 paired subcaudal scales. Females generally have 191 to 213 ventral scales and 80 to 90 paired subcaudal scales. Chocoan forest pit vipers have a long tail that ends in rounded spines that may slightly turn upwards at the tip. They have 6 to 9 intrasupraocular scales, 11 to 12 sublabial scales, and 7 to 9 supralabial scales. Adult females range from 60 to 90 cm in length, while males are on average smaller and less robust. Chocoan forest pit vipers can exceed 1 m in length. One Columbian specimen was 1.3 m long. (Bartlett and Wray, 2005)

Chocoan forest pit vipers practice internal fertilization. Developing embryos are held in the female's body and are born alive after a sufficient gestation period. It is currently unknown if this species is ovoviviparous (eggs retained during development, with no maternal nutrition to embryos) or viviparous (direct connection between female's bloodstream and embryos). Age at sexual maturity is unknown, though related species reach sexual maturity at 3 to 5 years of age. (Bartlett and Wray, 2005)

Little is known regarding the specific mating behavior of Chocoan forest pit vipers. This species is polygynous, meaning one male mates with multiple females. Many pit vipers engage in intrasexual combat, where males fight for access to a female or for territory. Males tree pit vipers typically mate once a year in either the spring or fall, and females usually mate yearly or every other year. (Bartlett and Wray, 2005)

Breeding behavior of Chocoan forest pit vipers in the wild is poorly understood, but is likely similar to that of closely related vipers. Two-striped forest pit vipers, Bothriopsis bilineata, give birth to 2 to 6 young per litter in captivity. However, larger vipers, such as Bothrops colombiensis, give birth to larger litters of 20 to over 50 young. Age at sexual maturity is unknown, though related species reach sexual maturity at 3 to 5 years of age. (Bartlett and Wray, 2005)

Female Chocoan forest pit vipers provide nutrients to their young during gestation. Post-natal care is not documented for this species. However, some viperids display brief parental care, with mother snakes remaining near newborns for hours to a day or two after birth.

Lifespan of Chocoan forest pit vipers has not been recorded in the wild. One individual of the related species in the genus, Bothriopsis bilineata, survived in captivity for over 13 years. Other neotropical tree vipers have lived over 20 years in captivity. Few, if any, wild individuals attain this longevity.

Chocoan forest pit vipers are active year round and are territorial. Males may fight for access to mates or territory. They are nocturnal and spend their days anchored by their prehensile tails, camouflaged in foliage, tree hollows, or in palm fronds. They have been described as "sluggish and slow to arouse" (Campbell and Lamar 2004). Chocoan forest pit vipers are largely solitary, except during the mating season.

Pit vipers, including Chocoan forest pit vipers, are known for their defensive behaviors. They curl up into a coil and stick their head out of the middle when threatened. They also hiss, jerk their head forward, or blow up their bodies to make them look bigger in order to scare off predators. (Campbell and Lamar, 2004)

Little is known regarding the natural home range or territoriality of Chocan forest pit vipers.

Like all snakes, Chocoan forest pit vipers use their tongue and vomero-nasal (Jacobson's) organ to sense and interpret chemical odors in their environment, to navigate, find food and mates, and for defense. The heat-sensing pit-organ in front of their eyes can sense the warmth (infra-red energy) of other organisms. The use of vision and sound is relatively unstudied in this nocturnal species.

Chocoan forest pit vipers do not often actively hunt, but rather usually "sit and wait" to ambush their prey. They feed on small mammals, frogs, lizards, and possibly birds. (Bartlett and Wray, 2005)

Specific predators of Chocoan forest pit vipers have not been identified. They are likely preyed upon by a number of avian and mammalian predators, especially when young. Humans also likely kill these snakes.

Forest pit vipers are mostly nocturnal and highly cryptic, spending much of their time immobile and hidden in vegetation or tree cavities, which makes them difficult to spot. When attacked, their fangs and venom present a formidable defense.

Chocoan forest pit vipers prey on a variety of small vertebrates and are likely preyed upon by larger birds and vertebrate predators. Vipers also host numerous external (mites, ticks, etc.) and internal parasites such as nematodes, cestodes, and protozoans. (Bartlett and Wray, 2005)

Chocoan forest pit vipers may help reduce populations of rodents, which are considered pests by humans. Venom from vipers has been used in research on human medicines, although use of venom from this particular species has not been verified. Small forest vipers are occasionally captured for the pet trade, but are not recommended to be raised in captivity except by the most experienced keepers and zoos. (Bartlett and Wray, 2005)

The highly defensive nature of Chocoan forest pit vipers, along with their very toxic venom, can lead to crippling or potentially fatal bites to humans who threaten them. The extent of damage depends on how quickly the bitten individual receives medical care, including antivenin medication. The diverse variety of snake species in their natural range makes it crucial to identify the correct species of snake in order to receive proper treatment. These snakes are probably most dangerous at night, when they are most active and alert. (Bartlett and Wray, 2005; Kuch, et al., 1996)

Chocoan forest pit vipers have not been assessed by the IUCN, CITES, or the US Fish and Wildlife Service. Deforestation as well as habitat destruction and fragmentation are major threats to habitat for this species.

Taxonomic classification of this species is still under debate. Species in the genus Bothriopsis were formerly placed in the genus Bothrops, and the latter is sometimes preferred (see Campbell and Lamar, 2004). (Campbell and Lamar, 2004)