Massasauga Rattlesnake (Sistrurus catenatus)
Common Name: Massasauga Rattlesnake
Scientific Name: Sistrurus catenatus
Adults are not large, ranging from 45 to 75 cm in length. Its color pattern consists of a grey or tan ground color with a row of large rounded brown/black blotches or spots down the centre of the back and three smaller rows of alternating spots down each side. A rattle is present on the tail. Young massasauga rattlesnakes are well-patterned but paler than the adults. This is the only Ontario snake with vertical pupils. It has heat-sensing pits on each side of its smallish head, the scales are keeled and the anal scale is single.