The Mexican black kingsnake (Lampropeltis getula nigrita), often called MBK, is a captivating and resilient reptile. This comprehensive guide offers scientific insights and practical advice for providing optimal care, ensuring a healthy and fulfilling life for your MBK.
What is a Mexican Black Kingsnake?
Mexican black kingsnakes belong to the genus Lampropeltis, a group of non-venomous colubrid snakes recognized by their characteristically shiny scales. The name Lampropeltis comes from Greek, meaning "shiny shield," referring to the kingsnake's head. These snakes are predominantly black, sometimes with white ventral scales. Adults typically reach 3-4.5 feet in length, while hatchlings start at 9-12 inches.
MBKs exhibit ophiophagy, or snake-eating behavior, though their diet is likely more varied.
Mexican black kingsnakes can be active during the day or night but are most active during twilight hours, making them crepuscular.
Their habitat is often arid and rocky, interspersed with lush vegetation.
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Habitat Parameters
Understanding the natural climate parameters of the MBK's habitat is essential for replicating a suitable environment in captivity.
Temperature
Climate data varies across the Mexican black kingsnake's range. Averaged data from Hermosillo and Nogales, locations near the US border, provide a representative understanding of their temperature preferences.
Disclaimer: Weather data from masts or anthropogenic structures may not accurately represent microclimates frequented by MBKs.
Mexican black kingsnakes prefer cooler air temperatures than some might expect. They tend to retreat to cool, humid hides when temperatures exceed 26°C/78.8°F. In winter, they seek insulated underground locations, with temperatures as low as 10°C/50°F being safe for captive hibernation.
A daytime ambient air temperature of 21-26°C/70-78.8°F is suitable for most of the year.
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Heating & Lighting Equipment
Provide a gentle basking spot at one end of the enclosure to allow the snake to bask if desired. Use a low-wattage heat bulb, such as the Exo Terra Intense Basking Spot Lamp or the Zoo Med Repti Basking Spot Lamp, connected to a thermostat with the probe placed in the cool/shaded end of the enclosure. Ensure the probe is not touching objects or under lights that could cause a false reading. Set the thermostat to 26°C/78.8°F to prevent overheating.
A UVB lamp should also be provided, as UVB exposure plays a role in managing health in the wild. While MBKs can survive without UVB, it enhances their health by aiding in Vitamin D production, supporting calcium metabolism, and bone strength. Following recommendations from Arcadia Reptile, aim for a UV Index of 2-3 in the tank, achievable with a 6% T8 UVB at 10-15″ height or a T5 6% UVB or T8 12% UVB at 15-18″ height.
Turn off heating and lighting equipment at night, allowing the temperature to cool. In most homes, supplemental nighttime heat is unnecessary. However, if needed, use a non-light-emitting heat source like a ceramic heat emitter on a thermostat set to 10°C/50°F, which will only activate when hibernation temperatures are reached.
Humidity
Humidity in the wild correlates with rainfall, with the monsoon season bringing lush vegetation to their habitats. In captivity, maintaining an average humidity of 30-50% with a humid hide allows the snake to self-regulate its needs. Provide a water bowl large enough for soaking.
Substrate and Decor
MBKs enjoy digging, so provide a substrate that supports burrowing and retains moisture. Excellent options include topsoil mixed with play sand or premixed products like Reptisoil, at a depth of several inches for tunneling. Dry substrates like aspen shavings can be used, but ensure a humid hide is available to compensate for the lack of moisture.
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A cluttered environment enhances the snake's sense of security. Include cork bark, branches, and hides, and offer climbing opportunities to encourage muscle use.
Mexican Black Kingsnake Diet
Mexican black kingsnakes consume a varied diet in the wild. While there is no specific study on the MBK's diet, research on the closely related California kingsnake (Lampropeltis californiae) found that their diet consisted of 29% mammals, 29% snakes, 25% lizards, 11% birds, 4% squamate eggs, 1% unidentified squamates, and 1% amphibians.
It is logical to assume that the MBK's diet is similar. Therefore, offer a varied diet in captivity, using rodents as a foundation and occasionally incorporating other food items.
Suitable food items include:
- Mice
- Rats
- Hamsters
- Gerbils
- African soft furs
- Day-old chicken chicks
- Quail chicks
- Quail eggs
- Older quails
- Reptile eggs
- Frog legs
- Anoles
- Reptilinks sausages
For young MBKs, feed a prey item that is 10% of the snake's total weight every 5 days, then shift to every 10 days in adulthood. This often involves feeding pinkie mice, then hoppers, then small, medium, large, and XL mice. As adults, feeding every 10 days is recommended for maintenance. If the kingsnake seems constantly hungry or bites unusually, feed every 7 days. If it becomes overweight, reduce feeding to every 14 days and/or decrease prey size. More frequent feeding may be necessary for reproduction or during periods before or after brumation.
It generally takes them 48 hours from eating to pooping.
Hibernation
Hibernation is beneficial for breeding and may extend lifespan. A study on rat snakes found that hibernation extended captive lifespans by 33%. Though not specific to MBKs, their close relation suggests similar benefits.
To hibernate in captivity:
- Feed the last meals around Halloween.
- Allow a week for digestion and emptying.
- Slowly reduce the maximum ambient air temperature and daylight hours each week.
- Around mid-November, turn off the tank completely and allow it to cool.
The enclosure can remain at 10°C/50°F all winter. Alternatively, box the snake in a container with substrate, a hide, and a water bowl, and place it in a cold location like a basement. Leave them until the end of February, then return them to their enclosures. Over a week, slowly turn the lights back on and raise the temperature on the thermostat. By March, everything should be back on, and the snakes should be awake.
After hibernation, offer small meals initially to ease them back into feeding.
Breeding
Disclaimer: Before breeding Mexican black kingsnakes, ensure you have a plan for the offspring or the means to house them long-term.
Breeding MBKs is relatively straightforward. After both male and female have awakened from hibernation, feed the female heavily to prepare her for breeding condition. After a couple of small meals, feed her a decent-sized meal (10% of body weight) every 5 days. The male can be fed normally every 7 days unless he refuses food.
Wait for the female to have her first shed cycle of the year (the pre-ovulation shed). Then, introduce the male into her enclosure. Observe for jerky movements as the male follows the female. The male will often bite the female by the neck and align himself with her before mating, which can last a couple of hours. Some keepers cohabitate the pair during this time to ensure repeated locks. After the snakes separate, remove the male from the enclosure. Introduce the male again a few days later for a second lock.
After this, keep them separate and continue feeding the female on the 5-day schedule. The humid hide can serve as a lay box. The next shed after this is often called the pre-lay shed. About 10 days after shedding, the female may lay her clutch.
If successful, the female will appear deflated. Check her belly to ensure she does not have any retained eggs. If all is good, remove the eggs and continue the feeding schedule until her condition recovers.
To incubate MBK eggs, provide humidity without stagnant air. Use a plastic tub with vermiculite as a substrate, moistened to a sandcastle-building consistency. Cover the bottom of the tub with an inch of vermiculite. Drill holes on opposing sides of the tub for cross-ventilation. Place the entire clutch on top of the vermiculite, without separating the eggs. Studies suggest that neonates communicate with each other while still in the egg, and lone incubation may affect hatchling demeanor.
If eggs show signs of molding, spray them with Leucillin, a wound-healing/disinfectant spray made from hypochlorous acid, which is safe and effective.
Place each neonate into its own tub with a water bowl, hide, and moist paper towel substrate. After a week or so, when the neonate has absorbed its yolk and had its first shed, switch to a loose substrate and add a humid hide with moss. Maintain a small, low-wattage heat mat with a warm spot at 26°C/78.8°F, allowing the ambient air temperature to drop to room temperature.
First, offer very small pinky mice ("red hots") by leaving them in the enclosure overnight. If they don't eat, wait a week and repeat. If an animal refuses to eat, begin with assist feeding and then force-feeding.
Once they are feeding, they wolf down everything in front of them quite happily. Not all clutches will grief you so, I’ve had some clutches that were painful and others that all at on week one.
Natural History
The Mexican black kingsnake follows a life cycle typical of many colubrid snakes, progressing through egg, hatchling, juvenile, and adult stages. Adults breed in the spring and early summer, with females laying clutches of 6 to 20 eggs in concealed locations such as burrows or rotting logs. The eggs incubate for approximately 55 to 70 days, depending on temperature and humidity conditions. Upon hatching, juveniles emerge as fully independent miniature versions of adults, measuring around 8 to 10 inches in length. Growth is relatively rapid in the first year, with individuals often exceeding two feet by the end of this period. Sexual maturity is typically reached between two and three years of age, depending on factors such as food availability and environmental conditions. In the wild, lifespans generally range from 10 to 15 years, though captives provided with optimal care can exceed 20 years.
This species is primarily a terrestrial snake but is also an adept climber when necessary. It is typically crepuscular, most active during the early morning and late evening hours, though it may become more nocturnal during hotter seasons to avoid extreme daytime temperatures.
The Mexican black kingsnake is a powerful constrictor, using its strong body to subdue prey by coiling around it and tightening until suffocation occurs. Its diet consists of a variety of small vertebrates, including rodents, birds, amphibians, and other reptiles. One of its most notable behaviors is its immunity to certain venoms, allowing it to prey on rattlesnakes and other venomous species without harm.
Though largely solitary and territorial, these snakes may tolerate brief interactions with others of their kind during the breeding season. When threatened, they rely on defensive behaviors such as rapid vibratory tail movements, musking, or flattening their bodies to appear larger. Unlike some of their close relatives, they rarely resort to biting unless provoked.
Ecologically, the Mexican black kingsnake plays a crucial role in balancing local food webs. As both predator and prey, it helps regulate populations of small mammals and reptiles, preventing overpopulation and the spread of disease. In areas where rodents are abundant, these snakes serve as natural pest controllers, reducing crop and property damage caused by these animals. They, in turn, are preyed upon by larger birds of prey, such as hawks and owls, as well as mammals like foxes and raccoons. Their adaptability to various habitats, including arid deserts, scrublands, and grasslands, allows them to maintain stable populations across their range.
The dark, near-solid black coloration of this species provides advantages such as enhanced heat absorption, which aids in regulating body temperature in cooler conditions, and camouflage against predators in shadowed environments. By fulfilling these ecological functions, the Mexican black kingsnake contributes to maintaining biodiversity and ecosystem stability across its natural range.
Native Range
The Mexican Black Kingsnake is native to northwestern Mexico, primarily in the states of Sonora and Sinaloa. Its natural range is relatively restricted compared to more widely distributed kingsnake species, but within this range, it inhabits a variety of ecosystems. This species is typically associated with arid and semi-arid regions, including thorn scrub forests, dry tropical forests, and open desert landscapes. It is often found in areas where vegetative cover provides refuge while still allowing access to open spaces for thermoregulation and hunting. The species' adaptability to different environmental conditions enables it to thrive in habitats that experience significant seasonal variations in temperature and humidity.
At the macrohabitat level, the Mexican Black Kingsnake is typically found in dry, subtropical regions characterized by sparse vegetation, rocky outcrops, and occasional riparian corridors. These environments experience drastic shifts between wet and dry seasons, influencing the snake’s activity patterns. The microhabitat preferences of this species include areas beneath rocks, within abandoned rodent burrows, and under fallen logs, where moisture retention and stable temperatures provide refuge from extreme environmental conditions. This snake is also known to inhabit the edges of agricultural fields, where the combination of disturbed land and an increased rodent population creates favorable hunting conditions.
Climatically, the species thrives in regions with hot summers and mild winters. During the warm season, daytime temperatures can exceed 90°F, while nighttime temperatures often drop significantly. In cooler months, daytime temperatures range from 65-75°F, and the species may experience a period of reduced activity or brumation in response to colder conditions. Precipitation in its native range is highly seasonal, with most rainfall occurring during the summer monsoon months, leading to temporary increases in humidity. However, for the majority of the year, humidity levels remain relatively low, typically ranging between 30-50%, except in riparian zones where localized moisture is higher.
The species is most commonly found at low to mid-elevation environments, generally ranging from sea level to approximately 5,000 feet above sea level. It is rarely encountered at higher elevations, as cooler temperatures and reduced prey availability make such habitats less suitable for survival. One of the key environmental factors influencing the distribution of this species is the presence of rocky or sandy soils that facilitate burrowing and provide stable microclimates. Additionally, access to water sources, such as seasonal streams or permanent water bodies, may play an important role in the local abundance of prey species, indirectly affecting the kingsnake’s distribution. The combination of habitat structure, climate, and prey availability shapes the ecological niche of the Mexican Black Kingsnake, making it an adaptable yet highly specialized predator within its native range.
Behavior
The Mexican black kingsnake is a primarily terrestrial, non-venomous colubrid that exhibits distinctive behavioral traits both in the wild and in captivity. Seasonal activity shifts occur, with individuals slowing down or entering a state of brumation during cooler months, particularly in regions experiencing significant temperature drops. In captivity, this natural fluctuation in activity can still be observed, especially in enclosures with seasonal temperature variations.
This species is solitary in nature, preferring to hunt, bask, and shelter alone. While not overtly territorial, individuals may display aggression toward conspecifics, especially when resources such as food or optimal hiding spots are scarce. Kingsnakes are known for their opportunistic feeding behavior, and in some cases, cannibalism can occur, particularly in confined spaces such as captivity where encounters are more frequent.
During the breeding season, males engage in combat to establish dominance, intertwining and pressing against one another in an attempt to pin their opponent. Courtship behavior consists of the male using body movements and tactile cues to stimulate a receptive female, often nudging or coiling around her before mating. There is no parental care beyond egg-laying; females deposit clutches in secure, humid environments, leaving the eggs to incubate naturally.
This species is highly responsive to environmental stimuli, using both visual and chemical cues to navigate its surroundings. It relies on its forked tongue and Jacobson’s organ to detect pheromone trails left by potential prey or mates. Temperature changes influence its activity levels, with increased movement and feeding during warm, stable conditions. Humidity also plays a role, particularly in aiding proper shedding cycles.
In the presence of a perceived threat, the snake may employ a variety of defensive tactics, including cloacal musk release, rapid escape movements, or mimicry of venomous species by vibrating its tail in leaf litter to resemble a rattlesnake. While it is not generally aggressive toward humans, individuals may bite if restrained or excessively provoked.
A notable behavioral trait of the Mexican black kingsnake is its specialized feeding strategy. As an ophiophagous species, it is capable of preying on other snakes, including venomous species, demonstrating a resistance to certain venom toxins. It kills prey through constriction, applying pressure in rhythmic waves until its target succumbs. This species also displays strong foraging tendencies, actively seeking out prey rather than ambushing from a stationary position. When basking, it exhibits deliberate thermoregulatory behavior, shifting between warm and cool areas to maintain optimal body temperature. Unlike some arboreal relatives, this species is not a proficient climber, though it may explore elevated surfaces opportunistically.