This pie chart shows the relative likelihood of observing particular other species commonly observed near Crotalus ruber

Range and Population:

The species' range extends from southwestern California in the United States (from near Pioneertown and Morongo Valley of San Bernardino County and southeastern Los Angeles County) south through Baja California (Mexico), including several islands in the Gulf of California (e.g., Angel de la Guarda, Pond, San Marcos, Danzante, Monserrate, and San Jose islands) and Isla de Santa Margarita and Isla Cedros along the Pacific coast of Baja California to Los Cobos (Murphy et al. 1995, Grismer 2002, Campbell and Lamar 2004). This species does not occur in the desert east of the Sierra de Juarez in northeastern Baja California (Campbell and Lamar 2004). Its elevational range extends from near sea level to about 1,500 m asl but usually below 1,200 m asl (Campbell and Lamar 2004).[1]
Countries:Native:
Mexico; United States

[1]
Population:This species is represented by a large number of occurrences (subpopulations). In California, Jennings and Hayes (1994) mapped roughly 80 extant locations and about 45 locations from which the species was believed to be extirpated. Campbell and Lamar (2004) mapped about 27 collection sites in Baja California. The adult population size is unknown but presumably exceeds 10,000. Jennings and Hayes (1994) estimated that about 20% of the suitable habitat in California has been lost. Declines have been much less severe in Baja California, though it has disappeared from urban areas. Currently, its extent of occurrence is stable whereas its area of occupancy, number of subpopulations, and population size are probably slowly declining; overall, the rate of decline is probably less than 10% over 10 years or three generations. Population Trend: [1][1]

Ecology Notes:

Habitats are varied and include rocky areas of tropical deciduous forest, ocean shores, desert scrub, thorn scrub, open chaparral, mesquite-cactus, and pine-oak woodland, sometimes also dunes, grassland, and cultivated areas between rock outcrops (Grismer 2002, Stebbins 2003, Campbell and Lamar 2004). In southern California, this snake is most common in the western foothills of the Coast Ranges and in dry rocky inland valleys (Ernst 1992, Ernst and Ernst 2003, based on Klauber's studies in San Diego County); it often inhabits areas of granite rock outcroppings, especially in winter (Armstrong and Murphy 1979). In southern Baja California, it is most common in heavy brush where rocks and rocky outcrops are prevalent, but it also occurs in desert and open arid plains (Armstrong and Murphy 1979). This terrestrial snake commonly climbs into low vegetation. Refuges include rock crevices, animal burrows, brush piles, surface debris, or similar sites.[1]

List of Habitats:1.4Forest - Temperate 3.4Shrubland - Temperate 3.8Shrubland - Mediterranean-type Shrubby Vegetation 4.4Grassland - Temperate 6Rocky areas (eg. inland cliffs, mountain peaks) 8.2Desert - Temperate

In sections below, we make some habitat inferences based on the known habitat preferences of those species most commonly associated with Crotalus ruber.

Zone:

alpine, montane, subtropics, temperate.

Vegetation:

alpine meadows, boreal forest, coniferous forests, croplands, cultivated areas, deciduous woods and forests, desert, desert scrub, disturbed sites, fence rows, fields, forest edges, forests, gardens, grasslands, hardwood forests, mature forests, meadows, mesic forest, pasture, pine forests, rain forest, shrubby vegetation, thickets, tropical forest, tundra grassland.

Terrain:

dry slopes, flood plains, hillsides, pastureland, roadsides, rock outcrops, sand dunes, scree, streamsides, urban areas, valleys.

Soil and Rock:

clay, loam, sandy areas, sandy soil, stony areas.

Water in Area:

along rivers, bays, bogs, brackish water, coral reef, ditches, dry areas, estuaries, flood plains, lagoon, lakes, marshes, mesic areas, pelagic, ponds, rivers, saltwater, shores, stream banks, streams, swamps, swampy areas.

Slopes in Area:

hillsides.