Below you will learn about the types of snakes found in Puerto Rico.
Because of the geographic isolation of the islands, there are not as many snake species as you might expect here.
#1. Puerto Rican Racer
- Borikenophis portoricensis
Identifying Characteristics:
- Adults may grow to be three feet long.
- They have brown scales that are edged with darker brown.
- They have a neck hood, similar to a cobra but narrower.
Puerto Rican Racers are diurnal, largely terrestrial snakes in Puerto Rico that feed on lizards and small rodents. They bite their prey and use venom to hinder it. They typically move their prey to a secondary location before feeding.
Interestingly, Puerto Rican Racers possess a narrow neck hood similar to a cobra. These snakes can display this hood by raising the front part of their body off the ground. However, Puerto Rican Racers only display this hood if they’ve been provoked and are getting ready to strike.
While their venom is highly effective on small vertebrates, no fatalities have been reported from humans being bitten by Puerto Rican Racers. Reported symptoms from bites include swelling, immobilization, and severe numbness lasting up to a month.
Puerto Rican Racers are listed as a species of least concern on the IUCN Red List.
#2. Puerto Rican Boa
- Chilabothrus inornatus
Found only in Puerto Rico.
Identifying Characteristics:
- Adults’ maximum size is approximately 6.5 feet in length.
- Their base coloration may be gray, pale to dark brown, or chestnut.
- They have 70 to 80 darker-colored patches.
These snakes are often found in forested, rocky habitats in the foothills of the northwest and karst regions of Puerto Rico. They are nocturnal, semi-arboreal snakes and may be observed in trees or hanging from cliff walls waiting for prey.
Smaller boas primarily feed on anoles, while larger ones prey more on rodents, birds, bats, and other creatures. Some researchers recorded Puerto Rican Boas hanging by the mouths of caves to grab bats that fly in and out. They grab prey items with their mouth and then constrict and suffocate them before swallowing them head first.
Females give birth to litters of 23 to 26 live boas. The lifespan of wild Puerto Rican Boas is known, but scientists believe they may live between 20 and 30 years!
Historical records dating back to the 18th century indicate that these snakes were probably abundant in Puerto Rico before Spanish colonization. Unfortunately, these snakes were heavily hunted to produce snake oil. They were also negatively impacted by deforestation and the introduction of mongooses.
Some efforts have been made to help conserve this species, and it is currently listed as a species of least concern on the IUCN Red List but is still listed as endangered by the US Fish and Wildlife Service.
#3. Ground Snake
- Magliophis exiguus
Also known as Puerto Rican Garden Snakes and Virgin Islands Miniracer.
Found in Puerto Rico and the Virgin Islands.
Identifying Characteristics:
- Adults typically only reach 12 to 14 inches from snout to tail.
- Slender, pencil-like body.
- Dark brown with darker markings on their sides and whitish cheeks.
Ground Snakes are a terrestrial species often observed in the lower to middle sections of montane wet and dry forests though they may also occur in urban and rural garden settings. They spend most of their time on the forest floor beneath rocks, leaf litter, logs, branches, or other debris.
These secretive snakes prey mostly on anoles and some larger lizards in Puerto Rico. Ground Snakes seize their prey and inject it with venom. They wait until their prey has died or lost consciousness before swallowing it. Interestingly, the venom may begin digesting the prey before the snake has even swallowed it!
Female snakes lay clutches of 7 to 30 eggs. Researchers have observed eggs in different stages of development in one nest, indicating that females may lay successive clutches in one place or multiple females use the same nest.
#4. Striped Keelback
- Xenochrophis vittatus
Found in Puerto Rico.
Identifying Characteristics:
- Adult males typically grow up to 19.7 inches, while adult females reach up to 27.6 inches in length.
- They are bronze colored with black stripes running down the top and sides of the body.
- They have slender bodies, and their chin and ventral area are barred black and white.
These semi-aquatic, diurnal snakes are primarily found in aquatic habitats such as ponds, wetlands, and paddies. However, they may also be observed in open habitats like meadows, grasslands, scrublands, fields, suburban areas, and mature forests’ edges.
Although these snakes are native to western Indonesia, they have been introduced to Puerto Rico. In their native range, they are found from sea level to 3937 feet of elevation.
Striped Keelbacks feed on fish, amphibians, and lizards. They are rear-fanged and have mild venom to help immobilize prey. However, their venom is harmless. Striped Keelbacks are often kept as pets.
They breed year-round. Females lay clutches of 5 to 12 eggs. Hatchlings tend to be about 5 inches in length. Striped Keelbacks live for about ten years.
#5. Mona Island Boa
- Chilabothrus monensis
Found only on Mona Island in Puerto Rico.
Identifying Characteristics:
- Adult males typically measure between 27.6 and 40.4 inches from snout to vent, while adult females measure 28.4 to 49.4 from snout to vent.
- Coloration is gray-brown with 47 to 73 dark chocolate-brown blotches lined with darker pigment that may form complete or almost complete rings around the tail.
- Their heads are pale witha unique coloring that helps them blend into their environment.
Mona Island Boas are nocturnal and semi-arboreal. They’re found in forested areas on the coast and inland on the Island of Mona in Puerto Rico.
They prefer habitats with a high density of trees and a wide variety of tree structures, such as compound trunks, spreading crowns, and aerial roots. These habitats allow them to forage freely in the trees without having to descend to the ground and also provide ideal habitat for resting. Interestingly, larger individuals seem to spend more time higher in the trees than smaller boas.
It takes females about five years to reach sexual maturity, and they give birth to live young. The lifespan of these boas is largely unknown, but they’ve been reported to live for up to 11 years in captivity.
Unfortunately, Mona Island Boas are listed as endangered on the IUCN Red List. One of the biggest threats to these boas is feral cats. One study found that 70% of all boas captured had healed injuries from feral cats. The island’s feral herds of goats, cattle, and hogs also destroy the understory habitat crucial for these boas and their prey.
#6. Boa Constrictor
- Boa constrictor
Also known as Red-tailed Boa, Common Boa.
Identifying Characteristics:
- These snakes grow 400 cm (157 in) long on average.
- Females are longer and wider than males.
- Coloration depends on their habitat. They can be shades of tan, brown, green, and even yellow or red.
- They have distinctive geometric patterns with ovals, diamonds, bands, and stripes.
The Boa Constrictor is so famous it doesn’t need a common name! Instead, people easily remember it by its scientific name, Boa Constrictor! Hailing from the humid tropics, this heavyweight snake can be spotted in trees and burrows in Puerto Rico.
Don’t let its large size fool you! The Boa Constrictor is an ambush predator that can strike with blinding speed. This snake is also a remarkable swimmer, so don’t be surprised to find one near a river or stream.
Boa Constrictors are a popular attraction in zoos all over the world. In captivity, they can live for over 40 years. They’re generally docile, but they’ll still deliver a warning bite if they feel threatened. Thankfully, they’re non-venomous.
#7. Brahminy Blindsnake
- Indotyphlops braminus
Found on the Caymans Islands, Puerto Rico, and St. Croix.
Identifying Characteristics:
- Adults are 5.1-10.2 cm (2-4 in) long.
- Their coloring varies; charcoal gray, light yellow-beige, silver-gray, purplish, and white are common.
- The body shape is worm-like, and they are easily mistaken for earthworms.
You will probably never see this small snake in Puerto Rico.
The Brahminy Blindsnake, as its name suggests, is almost completely blind. It has small, translucent eyes that can detect light but not form images. This snake species is not native to Puerto Rico. Instead, it arrived here by being transported in the soil of potted plants, which has earned them the nickname “Flowerpot Snake.”
They spend almost all their time underground in ant and termite nests and live under logs, moist leaves, and stones. Look for them in urban gardens and moist forests.
When distressed or attacked, the Brahminy Blindsnake will try to escape underground. If touched, it might press its tail on the attacker and release a smelly musk. Despite its rather creepy appearance, this snake is completely harmless to humans.
Which of these snakes have you seen before in Puerto Rico?
Learn about 16 Common BIRDS That Live in Puerto Rico HERE!
