Western Rat Snake
Pantherophis obsoletus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Natural range includes central North America, specifically from the Mississippi River west to the Rocky Mountains and from southern Canada down to the Gulf of Mexico.
Look up Western Rat Snake in the Snake Encyclopedia →Venomous Status
Non-venomous (aglyphous)
Danger Level
Harmless. Though they can be defensive and bite if handled, they pose no toxic threat to humans.
Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Conservation
IUCN Least Concern. Threats include habitat loss and intentional killing due to being mistaken for venomous species.
Physical Description
Juveniles and sub-adults (like this specimen) feature a greyish background with dark brown or black blotches. As adults, they may become solid black depending on the region. They have weakly keeled scales, round pupils, and a white or checkered belly.
Size & Dimensions
Specimen appears to be a juvenile/sub-adult approx 1.5 - 2 feet. Adults typically range from 3.5 to 6 feet, with record lengths near 8 feet.
Habitat
Highly adaptable; found in woodlands, rocky canyons, grasslands, and agricultural areas. They are excellent climbers (arboreal) but also frequent terrestrial habitats and human-made structures like barns.
Behavior & Temperament
Generally docile but can be very defensive when cornered. They are famous for 'kinking' their bodies, rattling their tails in dry leaves to mimic a rattlesnake, and gaping their mouths or lunging as a bluff (as seen in the photo).
Diet & Feeding
Active forager and constrictor. Primarily consumes rodents (rats, mice), birds, and bird eggs. Often referred to as a 'farmer's friend' for pest control.
Reproduction
Oviparous (egg-laying). Females lay clutches of 10-30 eggs in early summer, which hatch in late summer or autumn.
Venom Profile
Non-venomous - no medically significant venom.
Look-alikes
Often confused with the Western Fox Snake, Bullsnake, or North American Racer (juveniles). Defensive displays often lead people to misidentify them as Cottonmouths or Rattlesnakes.
Conservation Status
IUCN Least Concern. Threats include habitat loss and intentional killing due to being mistaken for venomous species.
Cultural Significance
Ecologically vital for controlling rodent populations and maintaining the balance of local ecosystems. Frequently kept as pets in the reptile trade.
Notable Features
Remarkable climbing ability; they can scale vertical bark and brick walls. This specimen is exhibiting a classic 'gaping' defensive display to appear more threatening to a perceived predator.