Reptiles

Common Garter Snake

(Thamnophis sirtalis)

Species Description

**Description:** A slender snake with three yellow or greenish stripes running down a dark body. Patterning can vary and sometimes appear checkered.

**Size:** 18–26 inches long.

**Sexual Dimorphism:** Females are generally longer and thicker-bodied than males.

**Behavior:** Beneficial hunters of slugs and large insects. They are one of the few snakes that give birth to live young (up to 40 at a time).

**Habitat:** Most widely distributed snake in the region, often seen basking on rocks or garden paths.

💡 Fun Facts

Garter snakes are one of the few animals that can eat toxic toads without getting sick.
Common Garter Snake (Checkered Phase): A color variation where the typical stripes are accompanied by a bold, black-and-tan checkered pattern along the sides.
Common Garter Snake (Albino Phase): An extremely rare genetic variation lacking dark pigment, resulting in a yellow and pinkish snake with bright red eyes.
Common Garter Snake (Gravid Female): A visual record of a female in late summer, heavily swollen with live young before she gives birth to up to 40 miniature snakes.
Common Garter Snake (Melanistic Phase): A rare genetic variation where the snake is solid jet-black, lacking all stripes; occasionally found in populations near the Allegheny reservoir.
**Description:** The most common snake in the region. They usually have three yellow or greenish stripes running down a dark body. The patterns can vary, sometimes appearing checkered.**Size & Weight:** They are slender snakes, typically 18 to 26 inches long. They weigh only a few ounces.**Sex Differences:** Females are generally longer and thicker-bodied than males.**Habits:** They are harmless to humans. When threatened, they may release a foul-smelling musk. They are one of the few snakes that give birth to live young (up to 40 at a time!) rather than laying eggs.
A solid black color variation of the common garter snake, occasionally found in the Allegheny region.
Garter snakes are social; in the winter, hundreds may gather in a single den to share body heat and survive the freeze.
Garter snakes are one of the few animals with a natural immunity to the toxins found in American Toads, allowing them to eat them without getting sick.
They are one of the few snake species that give birth to live young rather than laying eggs, sometimes having up to 40 babies at once.
When threatened, they can release a foul-smelling musk from glands at the base of their tail to deter predators.