Mexican Black Kingsnake Size: Adult Length and Growth Details

The Mexican black kingsnake (Lampropeltis getula nigrita) is a medium-sized, non-venomous colubrid popular in herpetoculture for its docile temperament and striking jet-black appearance.

Adult Size

• Typical length: 3–4 feet (90–120 cm)
• Maximum recorded: ~5 feet (152 cm) — rare
• Hatchlings: 8–12 inches (20–30 cm)
• Growth rate: Reaches adult size in 2–3 years with proper feeding

Physical Characteristics

• Color: Uniform glossy black (dorsal and ventral); faint white chin/lip markings
• Scales: Smooth, shiny; 21–23 midbody rows
• Body: Cylindrical, muscular; head barely distinct from neck
• Eyes: Round pupils; dark iris

Natural Range and Habitat

• Range: Northwestern Mexico (Sonora, Sinaloa, Chihuahua); possibly southern Arizona
• Habitat: Semi-arid rocky areas, thornscrub, tropical deciduous forest edges
• Behavior: Terrestrial, crepuscular/nocturnal; constrictor
• Diet: Rodents, lizards, snakes (including venomous), birds, eggs

Captive Care (Why Size Matters)

• Enclosure: 40-gal breeder (36×18×18") minimum for adult
• Feeding: Appropriately sized rodents (1–1.5× widest body) every 7–14 days
• Temperature: 75–85°F gradient; 88–90°F basking
• Humidity: 40–60%; higher during shed
• Lifespan: 15–20+ years in captivity

Subspecies Context

• Mexican black kingsnake = subspecies of common kingsnake (L. getula)
• Other subspecies: California kingsnake (californiae), speckled (holbrooki), Florida (floridana), eastern (getula)
• All similar size range (3–5 ft); Mexican black prized for solid color

A manageable size, striking looks, and hardy nature make the Mexican black kingsnake a perennial favorite—just respect its appetite and escape artistry.