The Mexican black kingsnake (Lampropeltis getula nigrita)—also known as the desert black or Western black kingsnake—is one of nine subspecies or geographic races of the common kingsnake. This subspecies is quite distinct from the others, exhibiting different coloration, behavior and habitat preference.
Mexican black kingsnakes are medium-size kingsnakes whose head is not distinct from the neck. Hatchlings are about 8 inches in length, and over the next two to four years reach an adult size of about 40 inches. In rare cases, the adults can reach 48 inches in length. These snakes are entirely black dorsally and ventrally, though young specimens and occasional adults display faded patterns. The eyes are small and dark, with round pupils.
Habitat and Range
Mexican black kingsnakes live in the Sonora and Sinaloa deserts as far north as Arizona. Though well adapted to the desert, these snakes often live in nearby semi-arid grasslands as well. Differing from most of their relatives, these snakes are nocturnal to avoid the desert sun; they spend their days hidden in rodent burrows or under debris, and emerge at night to prowl for food.
Like most kingsnakes, Mexican black kingsnakes prefer elongate, ectothermic prey such as lizards and snakes. Immune to the venom of native pit vipers, Mexican black kingsnakes are excellent predators of snakes. Despite the preference for lizards and snakes, Mexican black kingsnakes will consume virtually any animal small enough for it to overpower, including rodents, birds and frogs. They first bite their prey, and then wrap several coils around it and constrict it until it suffers cardiac arrest or stops breathing.
Predators and Self-Defense
Black kingsnakes have a number of predators, including hawks, owls, coyotes, foxes and feral cats. Their black color helps them to camouflage themselves from these predators as they prowl the ground at night. If cornered or threatened, Mexican black kingsnakes will rattle their tails, hiss and bite perceived threats. If a predator picks the snake up, the snake may expel a foul-smelling musk or defecate to dissuade the predator.
Mexican black kingsnake males begin seeking females in the spring. Mating occurs over the next one to two months. Mexican black kingsnakes are egg-layers that deposit a single clutch of up to 24 eggs annually. The females simply deposit the eggs and leave—they provide no parental care from this point forward. When prey is scarce, females may not breed every year. Hatchlings emerge 50 to 60 days later and must fend for themselves immediately.
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