General Distribution
The red diamond rattlesnake is distributed along coastal San Diego Co. to the eastern
slopes of the mountains and north through western Riverside Co. into southernmost San
Bernardino Co. Occurs from sea level to 900 m (3000 ft) in chaparral, woodland, and arid
desert habitats in rocky areas and dense vegetation. Young snakes are common on the
desert side but rare on the coast side of the mountains. This snake is active from mid-spring
to mid-fall (Tevis 1943, Stebbins 1954, Klauber 1972). Habitat Requirements
This snake occurs in rocky areas and in dense vegetation. It retreats into rodent
burrows, into cracks in rocks or under surface cover objects (Stebbins 1954, Klauber 1972).
This snake occurs in a wide variety of arid and semiarid habitats that provide
dense vegetation or rocky cover. Reproduction
Copulation occurs in March and April, with egg development requiring
approximately 4 months. The young are born from mid-August to October. Litters average 8
young and range from 5-13 (Stebbins 1954, Klauber 1972). Daily/Seasonal Activity
This snake is active from spring to fall, but the period of greatest activity
is from March to June. Early in the year it is active during the day but as daytime
temperatures increase it becomes active later in the evening. Eventually it is fully nocturnal
(Stebbins 1954, Klauber 1972). Probably does not migrate. Diet and Foraging
This snake feeds on rabbits, rodents, lizards, birds and other snakes (Stebbins
1954, Klauber 1972). Prey capture results from waiting for prey and active searching of
ground, rocky areas and off the ground in bushes. Territoriality/Home Range
Nothing is known. A report of a home range 8 m in diameter is obviously
wrong (Tevis 1943). Predator-Prey Relations
This snake is probably preyed upon by kingsnakes, roadrunners, and possibly
owls. Its close relative Crotalus viridis is sympatric with it in coastal areas, and they may
compete. Literature Cited
Klauber, L. M. 1972. Rattlesnakes: their habits, life histories, and influence on mankind.
2nd ed. Univ. California Press, Berkeley. 1533pp.
Stebbins, R. C. 1954. Amphibians and reptiles of western North America. McGraw-Hill,
New York. 536pp.
Tevis, L., Jr. 1943. Field notes on a red rattlesnake in lower California. Copeia
1943:242-245.
Information gathered from California DFG - California Interagency Wildlife Task Group
