Checkered Garter Snake
Thamnophis marcianus • Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
Found primarily in the southwestern United States (Texas, New Mexico, Arizona, Oklahoma), extending southward through much of Mexico and into Central America. Typically inhabits arid and semi-arid regions near permanent or temporary water sources.
Look up Checkered Garter Snake in the Snake Encyclopedia →Family
Order: Squamata, Suborder: Serpentes, Family: Colubridae, Subfamily: Natricinae, Genus: Thamnophis, Species: T. marcianus
Conservation
Listed as Least Concern on the IUCN Red List due to its wide distribution, presumed large population, and adaptability to modified environments.
Physical Description
Features a distinctive checkered pattern of dark square spots on a lighter olive, gray, or tan background, usually accompanied by a prominent light-colored vertebral stripe and pale lateral stripes on the sides. The head is slightly distinct from the neck with characteristic labial bars along the lips.
Size & Dimensions
Specimens typically range from 15 to 30 inches (38 to 76 cm) in total length, with females generally growing larger than males. This individual appears to be a sub-adult or adult of moderate length.
Habitat
Frequently found in close proximity to water such as streams, rivers, ponds, irrigation canals, and stock tanks in arid or semi-arid environments. They tolerate disturbed habitats and are often encountered in agricultural fields and suburban areas near water.
Diet & Feeding
An opportunistic predator feeding primarily on amphibians (frogs, toads, tadpoles), small fish, and occasionally earthworms or small mammals. It hunts actively using both visual and chemical cues.
Reproduction
Viviparous (gives live birth rather than laying eggs). Mating typically occurs in the spring after emerging from brumation, and females give birth to litters ranging from 4 to over 20 young in the summer months.
Look-alikes
Can be confused with other garter snake species (Thamnophis spp.) and ribbon snakes within overlapping geographic ranges. Distinguished primarily by the specific arrangement of the checkered dorsal spots and head markings.
Conservation Status
Listed as Least Concern on the IUCN Red List due to its wide distribution, presumed large population, and adaptability to modified environments.
Cultural Significance
Plays an important ecological role in controlling amphibian and invertebrate populations in wetland and aquatic edge ecosystems. They are commonly encountered by humans due to their tolerance of altered landscapes.
Notable Features
Exhibits excellent adaptation to arid environments by remaining closely tied to aquatic microhabitats and artificial water sources, allowing it to thrive in desert landscapes where water is scarce.