The Ridge-nosed Rattlesnake, Crotalus willardi, is a small species of venomous rattlesnake found in the southwestern United States and
Mexico. It is rarely found outside habitats of high elevation. They are found primarily in wooded mountain ranges primarily in the southwest. Human encounters with these snakes are considered rare events.
This is a rather small rattlesnake, with all subspecies measuring one to two feet in length. Color patterns are generally a dark-brown base with pale or white horizontal striping. There is some variation between subspecies. The distinctive ridges along each side of its nose, which are a series of upturned scales, are unique to its genus and are the origin of its name. Due to the size of this snake, venom discharge yields are low and not as harmful as with other rattlesnakes, although pain and discomfort can still result from a rare bite.
Due to lack of encounters with this species of snake, eating habits are not well known. Based on its size and habitat, its diet likely includes small mammals, birds and lizards that cross its path. Like other rattlesnakes, it is believed to be an ambush hunter. It coils up and lays waiting for prey to inadvertently wander into striking distance. These snakes are ovoviviparous, meaning it gives live birth. The young still develops within an egg inside the female until their time of birth. Broods are relatively small compared to other snakes, averaging about 5 young per clutch.