Photo credit:

Chad M. Lane

Common name

Northern Pacific Rattlesnake

Scientific name

Crotalus oreganus oreganus

Conservation Status

Least Concern

Federal and State Protections

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Countries of Occurrence

United States of America

States or Providence 

California, Oregon

Counties

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Adult size

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Species Description

This medium-sized rattlesnake can be found from central California up to southwestern Canada. They occur in grasslands and forests favoring drier, but not desert-dry, habitats. The Northern Pacific rattlesnake has a diet consisting primarily of mammals and birds as adults and lizards, shrews, and newborn rodents as juveniles. The mean clutch size of this rattlesnake is 5.5 with larger females having more babies born at a time.

Fun fact: Because of the shift from smaller, "longer" prey as juveniles to larger, more robust prey as adults, the venom of the Northern Pacific rattlesnake changes too! The venom of a juvenile is more toxic than that of an adult, and the venom of an adult rattlesnake here causes more hemorrhaging. However, it's important to know that juvenile rattlesnakes can control the output of their venom.