When encountering a snake with a distinctive pattern like black with yellow stripes, accurate identification is important for understanding local wildlife and for peace of mind regarding potential interactions.
Common Black Snakes with Yellow Stripes
The Thamnophis genus, including garter snakes and ribbon snakes, commonly fits the description of black snakes with yellow stripes. These snakes are widespread across North America, ranging from central Canada to Costa Rica. They typically feature a dark body color—black, brown, or olive green—adorned with longitudinal stripes.
Garter snakes (Thamnophis sirtalis) are a diverse group with numerous subspecies and varied appearances. Many common garter snakes have three brightly colored stripes, often yellow, running the length of their bodies. The Eastern Garter Snake (Thamnophis sirtalis sirtalis) is a prime example, often displaying a dark background with prominent yellow stripes. Some garter snake subspecies, like the California Red-Sided Garter Snake (Thamnophis sirtalis infernalis), can even feature blue or yellow stripes on a black and red background.
Ribbon snakes, also in the Thamnophis genus, share similar striped patterns. The Eastern Ribbon Snake (Thamnophis sauritus) typically has a dark brown or black body with three bright yellow stripes. The Western Ribbon Snake (Thamnophis proximus) also presents a dark body, often black or dark brown, with light-colored stripes that can be yellow or orange. These snakes are generally more slender than garter snakes.
Key Distinguishing Features
Differentiating garter snakes from ribbon snakes involves observing specific physical characteristics. Ribbon snakes are generally more slender with longer tails that can make up about one-third of their total body length, compared to garter snakes which have stockier bodies and shorter tails. The head shape also provides a clue, as ribbon snakes tend to have narrower heads than garter snakes.
The placement of the lateral stripes on their bodies is a consistent identifier. In garter snakes, the lateral stripes are typically found on the second and third rows of scales counting up from the belly. Conversely, ribbon snakes have their lateral stripes positioned higher, on the third and fourth scale rows.
Many ribbon snakes, such as the Eastern Ribbon Snake, have a distinct white spot or bar just in front of each eye, a feature generally absent in garter snakes. Ribbon snakes usually have uniformly white or yellowish lip scales without dark markings, whereas garter snakes often have vertical black lines on their lip scales. Both garter and ribbon snakes possess keeled scales, which are scales with a raised ridge, giving them a slightly rough texture.
Habitat, Diet, and Behavior
Garter and ribbon snakes are adaptable reptiles found across North America. Garter snakes inhabit diverse areas including meadows, woodlands, hillsides, and suburban gardens, often preferring moist, grassy habitats near water sources like ponds and streams. Ribbon snakes are more semi-aquatic, typically found in close proximity to water bodies such as lakes, streams, marshes, and wet woodlands, often basking on logs or vegetation near the water’s edge.
These snakes are primarily diurnal, active during the day, using their senses to hunt for prey. Their diets consist of various small animals. Garter snakes are generalist predators, consuming slugs, earthworms, leeches, amphibians like frogs and salamanders, fish, and sometimes small rodents. Ribbon snakes have a more specialized diet, feeding mostly on amphibians such as frogs, salamanders, and tadpoles, as well as small fish.
When threatened, both garter and ribbon snakes exhibit defensive behaviors. They will typically attempt to flee to safety, often seeking refuge in water or dense vegetation. If handled or cornered, they may flatten their heads, thrash about, or release a foul-smelling musk from glands at the base of their tails as a deterrent. Garter snakes might also strike or bite, though their bites are generally harmless to humans.
Safety and Coexistence
Garter and ribbon snakes are generally considered non-venomous and pose no significant threat to humans. While garter snakes produce a mild neurotoxic venom, their bites are comparable to a bee sting, typically resulting in only minor irritation, swelling, or bruising. Ribbon snakes are not venomous.
If you encounter one of these snakes, observe it from a distance and allow it to move away naturally. Handling them is not advised, as they may bite defensively or release musk. To discourage snakes from inhabiting yards, modify habitat by keeping grass mowed, removing debris like logs and rocks, and managing rodent populations.