Bull snakes are large, non-venomous constrictors found across North America, from southern Canada down into Mexico. They are a subspecies of the gopher snake, common in diverse habitats, including prairies, grasslands, and agricultural fields.
Key Physical Characteristics
Bull snakes possess a heavy, muscular body, typically 4 to 6 feet long, though some exceed 8 feet. Their substantial girth means they average 2.2 to 3.3 pounds, with larger specimens reaching up to 9.9 pounds.
The head is relatively small with a pointed snout. A prominent rostral scale, higher than it is wide, protrudes above adjacent scales, giving the snout its distinctive pointed appearance. Their scales are keeled, meaning each has a raised ridge down its center, giving a rough texture. Bull snakes also have small, round pupils.
Coloration and Patterns
The base coloration of bull snakes ranges from yellow, tan, or cream to light brown, providing camouflage. This background is overlaid with distinct dark blotches, often brown or black, along their back. These blotches are more pronounced near the neck and tail, becoming lighter towards the middle of the body.
Along the sides, smaller, similarly colored blotches form rows below the dorsal markings. The belly is much lighter, often yellowish or cream, with scattered dark spots creating a checkered pattern. This combination of colors and patterns allows bull snakes to blend effectively into their natural surroundings, such as grassy plains and sandy soils.
Distinguishing Bull Snakes from Similar Species
Bull snakes are often mistaken for rattlesnakes due to their size and defensive displays. Unlike rattlesnakes, bull snakes lack a physical rattle. While a bull snake may vibrate its tail against dry leaves to mimic a rattling sound when threatened, it is purely a bluff and not a true rattle.
Their head shape also differs; bull snakes have a more streamlined, narrower head proportionate to their body, in contrast to the distinctly triangular head of a rattlesnake. Bull snakes possess round pupils, whereas rattlesnakes, being pit vipers, have vertical, slit-like pupils and heat-sensing pits above their nostrils.
Bull snakes are also sometimes confused with other gopher snake subspecies; however, bull snakes are generally larger and can be identified by their prominent rostral scale.