Species Fact Profile: Aruba Island Rattlesnake (Crotalus unicolor)

Aruba Island Rattlesnake

Crotalus unicolor (van Lidth de Jeude, 1887)

Range: Aruba
Habitat: Rock Heaps, Scrub
Diet: Rodents, Birds, Lizards
Social Grouping: Solitary
Reproduction: Mating season September through January.  Males compete for females by wrestling, never using venom.  Female gives live birth to 5-9 young, which are independent (and venomous) from birth.  Sexually mature at 4 years for males, 5 years for females
Lifespan: 15-20 Years
Conservation Status: IUCN Critically Endangered, CITES Appendix III

• Short and stocky, body length 95 centimeters, weigh 900-1400 grams.  Males tend to be slightly larger than females
• Very light coloration, sometimes appearing almost white, other times light brown or pink.  (Latin name means "One-Colored Rattlesnake").  There is a slight keel to the scales, and in some individuals diamond-shaped markings, which typically don't show up well on the background color
• Nocturnal during the warmer months; during the rest of the year, it is active in early morning and late afternoon
• Finds prey using heat-sensitive pits between the eyes and nostrils; strike and kill prey using venomous bite, then swallows hole
• No predation in the wild has ever been observed, but natural predators likely include caracara, osprey, and other birds of prey.  Like other rattlesnakes, they have a rattle at the end of their tail to warn potential predators to steer clear
• Previously considered a subspecies of Crotalus durissus, the Neotropical rattlesnake
• Endangered due to its very small range, much of which has been disturbed or destroyed due to resort development, deforestation, and loss of vegetation due to introduced goats