Snake Bite FAQ

Kyoto: Hiking from Kibune to Kurama

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Identification: 30-89 inches. The largest western rattlesnake. Above: gray, brown or pink with brown diamond or hexagonal blotches on the back and fainter smaller blotches on the sides. Markings often indefinite and peppered with small dark spots, giving an overall speckled or dusty appearance. Tail set off from the rest of the body by broad black and white rings, about equal in width; hence sometimes called the "coontail" rattler. A light diagonal stripe behind the eye intersects the upper lip well in front of the corner of the mouth. Young: 9-14 inches, markings more distinct than in adult.

Frequents a variety of habitats in arid and semiarid regions from the plains into the mountains—desert, grassland, brushland, woodland, rank growth of river bottoms, rocky canyons, and lower mountain slopes. Crepuscular and nocturnal, but also abroad in daytime. Perhaps the most dangerous North American serpent, often holding ground and boldly defending itself when disturbed. Live-bearing.

Range: SE California to E Oklahoma and E Texas, south to Isthmus of Tehauantepec. Old records for central Arkansas and Trinidad, LasAnimas Co., Colorado. Sea level to 7000 feet.

Mojave Rattlesnake (Crotalus scutulatus)

Identification: 24-51 inches. Well-defined, light-edged dark gray to brown diamonds, ovals, hexagons down middle of back; light scales of pattern usually entirely light-colored. Ground color greenish gray, olive green, brownish, or yellowish. A white to yellowish stripe extends from behind the eye to a point behind the corner of the mouth except at extreme southern end of range. Tail with contrasting light and dark rings; dark rings narrower than light rings. Enlarged scales on snout and between the supraoculars.

Chiefly inhabits upland desert and lower mountain slopes, but ranges to about sea level near the mouth of the Colorado river and to highelevations in the Sierra Madre Occidental. Habitats vary—barren desert, grassland, open juniper woodland, and scrubland. This rattler seems to be most common in areas of scattered scrubby growth such as creosote bush and mesquite. Not common in broken rocky terrain or where vegetation is dense. Eats kangaroo rats and other rodents; and probably other reptiles. AN EXTREMELY DANGEROUS SNAKE; EXCITABLE AND WITH HIGHLY POTENT VENOM.

Range: S. Nevada to Puebla, near southern edge of Mexican Plateau; western edge of Mojave Desert, Calif. to extreme w. Tex. From near sea level to around 8300 feet.

In case of a bite it may be important to distinguish between the diamondback and the Mojave. The ranges of the species overlap and if you are in the area of overlap you may not know which was the culprit. The distinction is important in the case of a bite with little or no local reaction. In a diamondback bite, lack of reaction within 4 to 6 hours indicates that envenomation did not occur. However if a Mojave was the culprit no such assumption can be made and systemic reaction may occur 12 to 16 hours later. The two species are very similar in appearance. The relative width of light and dark tail bands may be the best way to distinguish between the two. If uncertain, assume the snake was a Mojave and treat accordingly.

Other similar snakes include the speckled and western rattlesnakes(there are several sub-species of the speckled). Their ranges also overlap those of the Mojave and diamondback.

Mojave venom can be up to 20 times the as potent as diamondback venom, although its quantity will typically be about 1/6 that of a diamondback. Specific references to Mojave and its unusual venom are:

The Venomous Reptiles of Arizona, (Arizona Game and Fish) pp 55-56.

Journal of Herpetology, Vol 23 no. 2, pp 131ff (1989)

Herpetologica, vol 47 No. 1 (March 1992) pp 54ff

One other note on the Mojave: There is a central Arizona version which can be considered a subspecies. The principal difference between it and its more widely distributed cousins is that its venom is very similar to diamondback venom. This therefore makes it less dangerous than other Mojaves. There are also hybrids which have components from both venom types. Hybrids present the particular danger of a local reaction which may fool victims and medical personnel into believing the culprit was some other rattler until the systemic reaction due to neurotoxin sets in later. Even experts can't tell the difference between different varieties of Mojave except by analyzing the venom.

There are a number of other species of rattlesnakes in North America. Information on their identification can by found in the Peterson or Audubon field guides.