When encountering a snake, many people wonder if its coloration signals danger. However, relying on color alone for identification can be misleading and unsafe. Accurate snake identification requires understanding various physical attributes.
Why Color Isn’t a Reliable Indicator
Snake coloration is remarkably diverse, even within the same species, making it an unreliable indicator of venomous status. Environmental factors, age, and genetic variations influence a snake’s appearance. For instance, rattlesnakes can display shades of brown, gray, green, or yellow, and their patterns can vary from diamonds to bands. Copperheads also exhibit a range of reddish-brown and coppery hues.
Many non-venomous snakes have evolved to mimic the coloration of venomous species, a phenomenon known as Batesian mimicry. For example, several harmless snakes, like kingsnakes and scarlet snakes, display red, black, and yellow banding similar to the venomous coral snake. The popular rhyme “red on yellow, kill a fellow; red on black, friend of Jack” is often unreliable for distinguishing coral snakes from their mimics due to significant color and pattern variations. Relying solely on color can lead to misidentification.
Key Features for Snake Identification
Instead of relying on color, observing specific anatomical features provides more reliable clues for snake identification. Many venomous snakes in North America, particularly pit vipers like rattlesnakes, copperheads, and cottonmouths, typically possess a broad, triangular-shaped head that is distinct from their narrower neck. However, some non-venomous snakes can flatten their heads when threatened, mimicking this appearance. Another indicator for many venomous species is the shape of their pupils, which are often vertical slits resembling a cat’s eye. Most non-venomous snakes have round pupils, though the coral snake is an exception.
Pit vipers also possess heat-sensing pits, small depressions located between their eye and nostril, used to detect warm-blooded prey. While characteristic, this feature is difficult to discern from a safe distance. Rattlesnakes are further distinguished by a rattle at the end of their tail, which produces a buzzing sound as a warning. However, young rattlesnakes may only have a single “button” and not yet produce a full rattling sound, and adults can sometimes lose their rattles. Combining multiple visual cues is more effective than relying on any single feature.
Identifying Common Venomous Snakes
Common North American venomous snakes have distinguishing characteristics. Rattlesnakes are identifiable by their heavy, thick bodies, triangular heads, and the namesake rattle at the tail’s end. Their coloration varies widely but often includes patterns of diamonds, bands, or blotches in shades of brown, gray, or olive. Copperheads are known for their reddish-brown or coppery bodies with dark, hourglass-shaped crossbands that are wider on the sides and narrower across the back. Younger copperheads often have a sulfur-yellow or green tip to their tail.
Cottonmouths, also called water moccasins, are heavy-bodied, semi-aquatic snakes that typically appear dark brown to black, though some may have faint crossbands, particularly when young. They are named for the distinctive white, cotton-like lining of their mouth, which they display when threatened. Cottonmouths also have a broad head and a dark stripe running through their eye.
Coral snakes are slender with striking red, yellow, and black bands that completely encircle their body. A key identifying pattern for North American coral snakes is that their red bands touch yellow bands. Their head is typically black with a yellow band behind the eyes, and they have small, rounded heads.
Encountering a Snake Safely
If you see a snake, give it ample space and avoid approaching it. Snakes generally prefer to avoid human contact and will often retreat if given the opportunity. Slowly back away from the snake, allowing it to move freely.
Never attempt to handle, provoke, or kill a snake, as this significantly increases the risk of being bitten. Most snake bites occur when people try to interact with them. If a bite does occur, seek immediate medical attention. Keep the bitten individual calm and still to help slow the spread of any potential venom, and avoid attempting to capture the snake for identification.