Crotalus oreganus
Male Pacific rattlesnakes (Crotalus oreganus ) during the mating season Kommentkampf
The Pacific rattlesnake (Crotalus oreganus ) is a species of rattlesnakes (Crotalus ) within the vipers ( Viperidae ), which has a very large range in the western United States to Canada. This type is often included as a subspecies of the Western Rattlesnake ( Crotalus viridis).
Features
The Pacific rattlesnake is a fairly large species of rattlesnakes, the lengths can vary greatly depending on the region and subspecies. The average length is about 1 meter, the length of record is 1,626 meters ( Klauber, 1956).
The basic color of the nominate C. o oreganus is dark brown, dark gray, and rarely black or light yellowish. The spinal pattern consists of a series of large, dark spots with irregular white border. The spots are larger than the areas between them. In addition, the species has more dark spots on the flanks, most are darker than the back and spots are clearly visible even in very dark individuals. The first cock rings the same color as the dorsal spots are back but darker up to the last two, which are colored black as a rule. The belly is pale yellow with brown speckles. On the head is a large, brown spot and a behind light area, which forms a cross bar on the About Eye shields. About the eyes a dark temple attracts tape with a white border to the mouth.
In this way differences occur during ontogeny. So young snakes are usually very distinct drawing patterns that fade in the course of development. The eye color generally corresponds to the basic color, ranging from gold, bronze, beige, pink to gray.
Distribution and habitat
The range of the snake extends from British Columbia, Canada, on the western half of the United States to the northern regions of Mexico. This area comprises the U.S., the states of Washington, Oregon, western and southern Idaho, California, Nevada, Utah, Arizona and central western New Mexico. In Mexico, she finds herself in Baja California and Baja California Sur. In their area of distribution it is possible to heights of 2,500 m.
In addition to the mainland, the snake lives on different islands:
- Morro Rock, California
- Anaho Iceland, Nevada
- Rattlesnake Iceland in Clear Lake
- Santa Catalina Iceland, California
- South Coronado Iceland, Mexico
System
In the Pacific rattlesnake currently seven subspecies are distinguished:
- CoN abyssus Klauber, 1930 in Arizona at the Grand Canyon on the Colorado River
- CoN caliginis Klauber, 1949 in Mexico on the South Coronado Iceland
- CoN cerberus ( Coues In Wheeler, 1875 in Arizona by the Hualpi Mountains and Cottonwood Cliffs in the north-west of the state to the Santa Catalina, Rincon, Pinaleno and Blue Mountains, also at the Steeple Rock in the far west of New Mexico
- CoN concolor Woodbury, 1929 in Colorado and Green River Basin in southwestern Wyoming and eastern Utah of 111 ° West and the Eastern Colorado
- CoN helleri Meek, 1905 in Southern California and Mexico on the northern Baja California, west of the desert.
- CoN lutosus Klauber, 1930 in the region of the Great Basin in Idaho, Arizona, west and east of the Colorado River, Nevada, eastern California and Oregon.
- CoN oreganus Holbrook, 1840 by the Pacific Coast in British Columbia, Canada, to Southern California.