Crotalus catalinensis - Santa Catalina rattlesnake

Meaning
catalinensis is a latinized spelling of the island Santa Catalina in the Gulf of California.

English name
Santa Catalina rattlesnake

Other names
Rattleless rattlesnake

Distribution
The only place this species of rattlesnake is found is on Santa Catalina Island in the Gulf of California. Not to be confused with the Santa Catalina Island off the coast of California USA.

Habitat
This desert island only covers 194 km² and has a rocky terrain, partially covered with bushes and cacti.

Description
The Santa Catalina rattlesnake is a slender medium sized snake, adults reach a length of around 60cm, and are fast, skillful climbers. There are two distinct color variations of the Santa Catalina Island rattlesnake. One is the light cream-brown colored base, with reddish-brown diamond shaped blotching down the back, and black and white banding around the tail. The other is a much lighter variant with an ash grey ground color, with darker grey blotching and similar bandings around the tail. On the head, there are pale stripes running through the centers of the supraoculars. The most unique feature of this species of rattlesnake is that it has no rattle. The proximal segment (at the base of the tail where the "button" is situated) is formed in such a way that the rattle immediately falls off with each shed instead of forming a new segment. It is thought that this anomaly is an evolutionary adaptation due to the arboreal tendencies when hunting for birds.

Diet
The lack of a rattle enables them to approach fast moving prey, such as birds - which are its primary diet, without alerting them as to the snake's presence.

Venom
The composition of the venom is unknown but likely to be simular to that of the Red diamond rattlesnake (Crotalus ruber) which occurs on the adjacent peninsula of Baja California and to which it may be most closely related.

Extra
This species has no protective status, only lives on this island and it is susceptible to extinction by collecting and the introduction of exotic predators such as feral cats. Unfortunately because of the negative attitude towards snakes in general there are no conservation or breeding programs for this snake.
Looking at the evolution of reptiles on Santa Catalina Island C. catalinensis is of a more recent origin than most other reptiles on the island.