California is home to nearly 50 native snake species, many of which display banded or patterned coloration, making accurate identification challenging. Understanding whether these snakes are poisonous or venomous requires precise terminology. The distinction between a harmless look-alike and a dangerous snake hinges on subtle physical features. Knowing the difference between the two terms and the characteristics of the state’s banded snakes is essential for safety.
Clarifying the Terminology: Venomous Versus Poisonous
The common use of the word “poisonous” for snakes is technically incorrect in a biological context. The difference between venom and poison lies in the delivery method of the toxin. A venomous animal actively injects its toxin using specialized apparatus like fangs or stingers. Conversely, a poisonous animal delivers its toxin passively, requiring the substance to be ingested, inhaled, or absorbed through the skin to cause harm.
California’s dangerous snakes are exclusively venomous because they inject their toxin through a bite. While some snakes globally are considered poisonous, California has no truly poisonous snakes that pose a significant threat to humans. Therefore, the safety concern is strictly related to potential envenomation, meaning the only native snakes of medical concern are the rattlesnakes.
Identifying California’s Venomous Banded Snakes
All of California’s native venomous snakes are rattlesnakes, which are pit vipers belonging to the genus Crotalus. The state is home to seven species and multiple subspecies, all possessing medically significant venom. While coloration varies, they often feature diamond-shaped blotches or a blotched pattern that can appear banded, especially near the tail.
Physical Identifiers
Rattlesnakes have several distinct physical identifiers that separate them from non-venomous species. They possess a broad, triangular-shaped head that is noticeably wider than their neck, characteristic of pit vipers. They also have two heat-sensitive pits located between the eye and the nostril, used to detect prey. Their eyes feature elliptical pupils, which appear as vertical slits, unlike the round pupils of most harmless snakes.
The Rattle
The most recognized feature is the rattle, composed of interlocking segments of keratin at the end of the tail. This structure produces a distinctive buzzing sound when the snake feels threatened. Young rattlesnakes are born with only a small button and may not produce a sound, and adults can break off their rattle. Some species, like the Western Diamond-backed and Mohave rattlesnakes, feature distinct black and white bands near the tail, which strongly indicate a venomous snake.
Harmless Banded Look-Alikes
Several harmless snakes in California exhibit patterns that can easily be mistaken for those of rattlesnakes. The California Kingsnake (Lampropeltis californiae) is a common example, recognized for its pattern of black or dark brown bands alternating with white or yellowish bands. Kingsnakes have slender heads that are not distinctly wider than their neck, and they possess round pupils.
Kingsnakes are non-venomous constrictors that are partially immune to rattlesnake venom and prey on them. They often mimic their dangerous counterparts by shaking their tail rapidly. This tail-shaking, particularly in dry leaves, can create a sound similar to a rattle.
The Gopher Snake (Pituophis catenifer) is another common non-venomous species frequently misidentified due to its coloration and defensive behavior. This snake has a blotched pattern that can resemble a rattlesnake’s markings and can grow quite large. When threatened, a Gopher Snake will hiss loudly and flatten its head into a more triangular shape to appear larger. However, Gopher Snakes lack the rattle and the facial pits of a true pit viper, ending instead in a pointed tail.
Safety Guidelines for Snake Encounters
The safest approach upon encountering any snake with a banded or patterned appearance is to assume it is venomous and maintain a safe distance. Snakes only strike when they feel threatened and will typically retreat if given the opportunity. Maintaining a minimum distance of six feet allows both the person and the snake to remain safe.
It is never recommended to attempt to capture, pick up, move, or kill any snake, as this is when the majority of bites occur. If a bite does occur, the individual should remain calm and seek immediate medical attention. Discouraging snakes from inhabiting residential areas can be achieved by removing potential hiding spots like piles of wood, debris, or dense brush.