Western Ratsnake (Black Ratsnake complex)
Pantherophis obsoletus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Commonly found throughout North America, specifically from east of the Rocky Mountains to the Atlantic coast, and from Ontario, Canada, south to the Gulf of Mexico.
Look up Western Ratsnake (Black Ratsnake complex) in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Colubrinae, Genus: Pantherophis, Species: P. obsoletus
Conservation
Least Concern (IUCN); however, they face threats from habitat fragmentation and frequent road mortality.
Physical Description
Elongated body with a somewhat 'loaf-of-bread' cross-section shape. This specimen shows a dark gray/black dorsum with a distinct light-colored labial (lip) and chin area. The scales are weakly keeled and the eye features a round pupil indicating diurnal or cathemeral activity.
Size & Dimensions
Typical adults range from 100 to 180 cm (3.3 to 6 ft). This juvenile/young adult specimen appears to be approximately 60-90 cm (2-3 ft) based on surrounding substrate.
Habitat
Generalist species found in forests, woodlots, rocky hillsides, and farm fields. Highly adaptable to suburban environments including backyards and barns. Occurs from sea level to over 1,300 meters.
Diet & Feeding
Active forager and powerful constrictor. Primarily feeds on rodents, birds, and bird eggs. Often referred to as a 'pilot' snake because they were once wrongly thought to lead rattlesnakes to denning sites.
Reproduction
Oviparous (egg-laying). Females lay clutches of 10 to 30 eggs in mid-summer, usually in hollow logs, mulch piles, or leaf litter. Hatchlings emerge in late summer or fall.
Look-alikes
Often confused with Racer (Coluber constrictor) which has smooth scales, or various species of King Snakes. Juveniles are heavily patterned and can be confused with Fox Snakes or Copperheads.
Conservation Status
Least Concern (IUCN); however, they face threats from habitat fragmentation and frequent road mortality.
Cultural Significance
Highly valued by farmers for excellence in natural rodent control. Historically protected in agricultural communities to keep grain stores free of pests.
Notable Features
Remarkable climbing ability; it is common to find them high in trees or scaling vertical brick walls using their unique ventral scale edges to grip textures.