On October 1, 2015, a juvenile eastern diamondback rattlesnake (Crotalus adamanteus) was found by Lee County staff and brought to CROW from the Sanibel Causeway. The last documented eastern diamondback rattlesnake on Sanibel was in 1996. They are currently considered extirpated on the island, but they still occur on two other large islands in Pine Island Sound (Cayo Costa and Pine Island). Eastern diamondback rattlesnakes and eastern indigo snakes (Drymarchon couperi) are considered colonizing snakes. They are known for traveling across large waterways and between islands. This snake is most likely a transient from Pine Island or some other small island in Pine Island Sound. This snake was relocated to Pine Island where diminishing populations still occur.