Aruba Island Rattlesnake Facts

Feared, worshiped, and almost always misunderstood, rattlesnakes are a fascinating and successful group of animals. The thirty species of rattlesnakes are found in the western hemisphere and have colonized a variety of habitats from southern Canada south into Argentina. The most widely distributed species is the South American rattlesnake (Crotalus durissus) for which eleven subspecies are recognized. One of these is a rare dwarf form which is found only on a small island of the north coast of South America, the Aruba Island Rattlesnake (Crotalus durissus unicolor).

  1. Geography

    • Found only on Aruba, a 12 square mile volcanic island nation off the north coast of Venezuela. The Aruba Island rattlesnake occupies the desert scrub habitat in the southern half of the island. There they live among the rocky boulders and cacti.

    Identification

    • Light brown, tan, to almost pink in ground color, the Aruba Island rattlesnake blends in well to the light soil color of its habitat. A series of dark brown to white or blue-gray diamond-shaped markings start just behind the head and run done the body to the tail. These markings are often indistinguishable from the ground color, giving a faded or solid light coloration. There are few markings on the head, but some individuals have two light stripes extending from the back of the mouth to the eye on each side of the head.

    Size

    • A moderately sized rattlesnake, the Aruba Island rattlesnake reaches an adult length of 35 inches. It is short and stocky in appearance. Males and females are indistinguishable by pattern, but males grow larger in size. Females reach maturity in five years while males do in four years.

    Warning

    • As with all rattlesnakes, the Aruba Island rattlesnake is venomous, but will not attempt to bite unless constrained or cornered. Their venom is considered to be one of the most toxic of all rattlesnakes, and their bite can be life-threatening for humans. Fortunately, bites from this seldom encountered snake are extremely rare.

    Threats

    • There are no natural predators to the Aruba Island rattlesnake in its limited native habitat. However, they are currently threatened by the encroachment of humans. Habitat destruction has eliminated the rattlesnake from the northern half of the island. Illegal collection for the pet trade and wanton destruction has further stressed these already reduced populations.

    Conservation

    • Population estimates for the Aruba Island rattlesnake are estimated at approximately 250 adults. The government of Aruba has promoted the rattlesnake as a national symbol, and afforded it protection with the designation of the Arikok National Park within its range. Ongoing research hopes to better define its habitat requirements, estimate its abundance, and determine life history characteristics to help direct future conservation efforts.

    Etymology

    • The name Crotalus is derived from the Latin word crotalum which means "rattle". The name unicolor is formed from the latin words uni (=one) and color (=color) alluding to the faded color pattern producing a uniformly washed out light coloration.