Pacific rattlesnake
| Pacific rattlesnake | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Male Pacific rattlesnakes ( Crotalus oreganus ) fighting for mating season |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Crotalus oreganus | ||||||||||||
| Holbrook , 1840 |
The Pacific rattlesnake ( Crotalus oreganus ), also Oregon rattlesnake , is a type of rattlesnake ( Crotalus ) within the vipers (Viperidae), which has a very large distribution area in the western USA to Canada . This species is often listed as a subspecies of the western rattlesnake ( Crotalus viridis ).
features
The Pacific rattlesnake is a relatively large species of rattlesnake, although lengths can vary widely depending on the region and subspecies. The average length is about 1 meter, the length record is 1.626 meters (Klauber, 1956).
The basic color of the nominate form C. o. Oreganus is dark brown, dark gray and rarely black or light yellow. The back pattern consists of a series of large, dark spots with an irregular white border. The spots are wider than the areas between them. In addition, the species has other dark spots on the flanks, most of which are darker than the back spots and are easily visible even in very dark individuals. The first tail rings are the same color as the back spots, but get darker towards the rear until the last two, which are usually black. The ventral side is light yellow with brown speckles. There is a large brown spot on the head and a light area behind it, which forms a crossbar on the over-eye shields. A dark band of temples with a white border extends over the eyes to the corners of the mouth.
In this species there are differences during ontogeny . Young snakes are usually very clear drawing patterns that fade in the course of development. The eye color usually corresponds to the basic color and ranges from gold, bronze, sand-colored, pink to gray.
distribution and habitat
.png)
The range of the snake stretches from British Columbia , Canada , over the western half of the USA to the northern regions of Mexico . The area in the United States includes the states of Washington , Oregon , western and southern Idaho , California , Nevada , Utah , Arizona and central-western New Mexico . In Mexico, it is found in Baja California and Baja California Sur . In its area of distribution it can occur up to an altitude of 2,500 m.
In addition to the mainland, the snake lives on different islands:
- Morro Rock , California
- Anaho Island , Nevada
- Rattlesnake Island in Clear Lake
- Santa Catalina Island , California
- South Coronado Island , Mexico
Systematics
There are currently seven subspecies of the Pacific rattlesnake:
- C. o. Abyssus Klauber , 1930 in Arizona in the Grand Canyon on the Colorado River
- C. o. Caliginis Klauber, 1949 in Mexico on South Coronado Island
- C. o. Cerberus Coues In Wheeler, 1875 in Arizona from the Hualpi Mountains and Cottonwood Cliffs in the northwest of the state to the Santa Catalina , Rincon , Pinaleno and Blue Mountains , also on Steeple Rock in the far west of New Mexico
- C. o. Concolor Woodbury, 1929 in the Colorado and Green River basins in southwest Wyoming and Utah east of 111 ° west and eastern Colorado
- C. o. Helleri Meek , 1905 in southern California and in Mexico on northern Baja California, west of the desert.
- C. o. Lutosus Klauber, 1930 ( Great Basin rattlesnake ) in the region of the Great Basin in Idaho , Arizona west and east of the Colorado River, Nevada , eastern California and Oregon .
- C. o. Oreganus Holbrook , 1840 from the Pacific coast near British Columbia , Canada , to Southern California.
Web links
- Crotalus oreganus in The Reptile Database
- Crotalus oreganus inthe IUCN 2013 Red List of Threatened Species . Posted by: Hammerson, GA, Frost, DR & Hollingsworth, B., 2007. Retrieved October 5, 2013.
Individual evidence
- ↑ For example in Chris Mattison: Rattler! - A natural history of rattlesnakes. Blandford, London 1996, ISBN 0-7137-2534-6 .
- ↑ a b c d e J.A. Campbell, WW Lamar WW: The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London 2004, ISBN 0-8014-4141-2 .