San Diego Natural History Museum--Your Nature ConnectionSDNHM Field Guide
El Muerto Island Speckled Rattlesnake, photographed by BDH

Crotalus muertensis
El Muerto Island Speckled Rattlesnake


Crotalus comes from the Greek crotalon, meaning a rattle or little bell; muertensis is a latinized spelling of the island El Muerto. For a long period of time, this species was recognized as a subspecies of Crotalus mitchelli. In Spanish, rattlesnakes are known as La Vibora de Cascabel.


The El Muerto Island Speckled Rattlesnake Rattlesnake is a small snake that grows to lengths of less than 28 inches (70 cm). This species is a dwarf of its peninsular counterpart, the Speckled Rattlesnake. Its coloration varies from grey to brown. The dorsal markings start off at the anterior as blotches but then widen to become crossbands posteriorly.

Range and Habitat

This species occurs only on Isla El Muerto, in the Gulf of California, México. This small island presents a harsh environment and its terrain is barren.

Natural History

Little is known about the natural history of this island endemic. It is known to occur throughout Isla El Muerto from the beaches to the steep slopes. It can be abundant around the cobblestone beaches where it most likely hunts lizards and rodents. It is active in both the day and night.

Conservation Status

Because this species only occurs on a single island, it is susceptible to extinction by collecting and the introduction of exotic predators such as feral cats. There has been no proposed conservation plans. Because of widespread negative attitudes towards snakes, very few conservation programs, worldwide, have been created. A much higher percentage of snakes are threatened with extinction than is currently recognized. Therefore, snakes are particularly susceptible to being overlooked by conservation-minded biologists.

Text by David Gonzalez and Bradford Hollingsworth.
Photos by Bradford Hollingsworth.

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