Checkered Garter Snake
Thamnophis marcianus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
North and Central America, ranging from the southwestern United States (Texas, New Mexico, Arizona, Oklahoma, California) southward through Mexico to Costa Rica.
Look up Checkered Garter Snake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
Conservation
IUCN Red List status is Least Concern, due to its wide distribution, presumed large population, and high adaptability to human-modified habitats.
Physical Description
Features a distinct checkered pattern of dark blotches on a lighter olive, gray, or brown background, with a prominent light-colored vertebral stripe and lateral stripes. The head has distinct labial bars and a parietal spot.
Size & Dimensions
Typical total length ranges from 40 to 90 cm (16 to 35 inches), with females generally growing larger than males.
Habitat
Found in a variety of semi-arid and arid regions, typically near permanent or temporary water sources such as streams, rivers, ponds, irrigation ditches, and marshes. Also adapts well to agricultural areas and suburban habitats.
Diet & Feeding
Diet consists primarily of amphibians (frogs, toads, tadpoles), fish, earthworms, and occasionally small rodents or lizards. They are active foragers that hunt primarily by sight and chemical cues.
Reproduction
Ovoviviparous (gives birth to live young). Mating typically occurs in the spring, and females produce litters ranging from 4 to 20 or more offspring in the summer months.
Look-alikes
Can be confused with other garter snake species (Thamnophis spp.) and ribbon snakes (Thamnophis saurita). Distinguished by the bold checkered pattern and specific scale counts.
Conservation Status
IUCN Red List status is Least Concern, due to its wide distribution, presumed large population, and high adaptability to human-modified habitats.
Cultural Significance
Acts as an important predator of aquatic pests like mosquito larvae and amphibian populations, helping maintain balance in wetland ecosystems.
Notable Features
Exhibits a very high tolerance for arid environments compared to many other garter snake species, often utilizing rodent burrows to escape extreme heat.