Western Rattlesnake

About the Western Rattlesnake

Crotalus oreganus, commonly known as the Western rattlesnake or northern Pacific rattlesnake, is a venomous pit viper species found in western North America from the Baja California Peninsula to the southern interior of British Columbia.

The size of this species varies greatly, with some populations being stunted and others growing very large. Mainland specimens often reach 100 cm (39 in) in length, with the largest on record being 162.6 cm (64.0 in) (Klauber, 1956) for C. o. oreganus. The species also varies in size in relation to its migration routes as individuals with longer and more linear paths tend to have more mass. The C. oreganus is classified with 6 subspecies with 3 of them being present within the state of California.

This species, in its various forms, shows considerable ontogenetic variation. Juveniles usually have more or less distinct patterns, but these fade as the animals mature. The color of the iris often matches the ground color, which may be bronze, gold, or different shades of tan, pink, or gray.

The habitat and/or the substrate of the Crotalus oreganus determines their coloration. The color pattern of the typical form, C. o. oreganus, has... Wikipedia →