Crotalus species

Common name:


Scientific name:

Crotalus species

Alternative common names:


Crotalusis agenusofvenomouspit vipersnaturally occurring in theAmericas,from southernCanadato northernArgentina. Therattlesnakescurrently found in South Africa include the sidewinder (Crotalus cerastes), which is a desert ambush predator. Members of this genus range in size from 50 – 60cm to over 150cm. Most forms are easily recognised by the characteristic rattle on the end of their tails, although a few island populations are exceptions to this rule.

Additional Information

Where does this species come from?

America, from southern Canada to northern Argentina.

What is its invasive status in South Africa?

NEMBA Category 2.

Where in South Africa is it a problem?


How does it spread?

Human encroachment, poaching for rattles and the pet trade are currently the primary reasons for its spread.

Why is it a problem?

Rattlesnake venom is life-threatening to a human when bitten, but the snakes only attack when provoked.

What does it look like?

Description: Members of this genus range in size from 50–60cm to over 150cm. Each snake is equipped with venom, hollow fangs and a tiny rattle segment called a ‘button’. Scales are ridged, giving this rattlesnake a rough-skinned appearance. Adult males are slightly larger than females. Their average life span is 16-22 years, with a maximum age of about 30 years.

Habitat: Rattlesnakes are generally found in deciduous forests in rugged terrain. In summer, pregnant females seem to prefer open, rocky ledges where temperatures are higher, while the males and other females seem to prefer cooler, thicker woods where the forest canopy is more closed.

Breeding: Mating occurs in spring and autumn. Males are especially active at this time, seeking out females by following the pheromone (sex attractant odour) they emit. The gestation period is four to five months. Females give birth to four to 14 (average nine) young every three to five years. The young are approximately 30cm in length at birth and emerge singly from the female, encased in a transparent membrane that is shed within minutes.

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