Aruba Island Rattlesnake

COMMON NAME: Aruba Island Rattlesnake

SCIENTIFIC NAME: Crotalus durissus

TYPE: Reptilia

DIET: Carnivore

GROUP NAME: Bed, knot

AVERAGE LIFE SPAN IN THE WILD: 12-20 years

SIZE: average size is approximately 3.28 feet (males are slightly larger)

WEIGHT: average weight is approximately 2.5 lbs.

As with most other rattlesnakes, Aruba Island rattlesnakes are heavy bodied, with a triangular head and a rattle-tipped tail. Dorsal scales are triangular and overlapping, with a slight keel. Diamond-shaped markings are present in a variety of colors ranging from a scarcely discernable white or rust color to an obvious dark brown or blue-gray. These markings blend into a pair of dark lines on either side of the spine which terminate at the head. The body color is also variable from light pink to dark tan, occasionally leaving the markings indistinguishable save for a small band along the spine. There are few markings on the head of this species; at most paired stripes extend from the eye toward the ventral boarder of the jaw. Conspicuous heat-sensing pits are visible below and slightly posterior to the nostrils, one on each side.

These reptiles hunt with the aid of their heat sensing pits, sight, and smell. Targeted species are mainly rodents, birds, and lizards, especially teiids. After prey is located, these snakes position themselves in a striking stance, characterized by an ‘S’ shaped neck. Launching itself forward, these rattlesnakes opens its mouth, allowing two venom delivering fangs to fold down and sink into the prey animal. The venom contains numerous chemicals, most notably proteolytic enzymes which begin to digest the animal before ingestion while other chemicals are responsible for increasing venom uptake and blocking energy to vital systems. After striking, the animal exhibits a period of increased tongue flicking in order to find the envenomatted prey.

Aruba Island rattlesnakes inhabit undisturbed sandy, rocky and arid hillsides of this volcanic island, now totaling only 12 square miles of protected land that includes the Arikok National Park. They are typically found on terraced mountainsides consisting of igneous rock and dry stream beds. The diabase mountains and limestone plateaus have been found to harbor the largest densities of this species, possibly due to the relatively low human presence. They are found from 2 meters above sea level to 188 meters elevation on Mount Jamanota. Oddly, despite the seeming preference for undisturbed areas, Aruba Island rattlesnakes are found within 1 km of the two largest cities on the island.

There are no reported natural predators of Aruba Island rattlesnakes, which are top predators in these habitats. Human encroachment and poaching for rattles and the pet trade are currently the primary threats to the population

Information on the Aruba Island Rattlesnake is courtesy of Animal Diversity.Org