Lampropeltis mexicana thayeri
Species: L. mexicana thayeri
Conservation Status: This is a widespread species found throughout a large range of remote regions in Mexico, this sub-species and the nominate form L. mexicana mexicana is listed as 'least concern'.
Natural History: The variable Kingsnake earns its common name well; these beautiful kingsnakes naturally occur in a collage of color and pattern variety. Some examples include dark melanistic animals, brightly contrasted tri-colors, thin mono-colored bands, large blotchy bands, and base colors of gray, tan, buff, peach and silver. This specific sub-species of the mexicana species complex is found only in the state of Tamaulipas, Mexico. There, it lives along the eastern facing slopes of dry arid plateaus in mostly montane habitats. Some animals may venture into scrubby grassland or lower lying desert environments but it strongly favors higher altitudes. These shy animals spend much of the midday concealed from excess heat and predators by hiding under and within rock formations, fallen trees, and clusters of dry vegetation or even man made debris. They are mostly crepuscular emerging in the early mornings and later evenings to bask and hunt. While capable climbers these kingsnakes tend to stay close to the ground where a quick retreat to a small space is possible. In the wild these animals feed heavily on lizards, but will also feed on smaller snakes, amphibians, reptile eggs and small mammals. Like many of the southwestern kingsnake species these are smaller, slighter animals, reaching maturity at around three years of age and measuring between 24-38” in length.
Care in captivity: Like many colubrid snakes, Variable kings are easy charges to care for. I utilize size appropriate rack tubs for my animals, but as long as the animals needs are met enclosures such as aquariums with secure lids, & specialized reptile enclosures work just as well. I utilize thermostatically controlled flexwatt as a heat source and maintain the animals with a ‘basking’ or ‘hot’ side in the mid to high 80’s with a natural gradient away from the heat that drops in the mid 70’s. Nighttime temperatures are allowed to drop a few degrees from the daytime highs as well. I utilize aspen shavings as a substrate for adults and larger juveniles, and layered paper towels for hatchlings. These shy snakes need a couple size appropriate hide boxes and will spend most of the day under the substrate or within either the warm or cool side hide box. A small reservoir of clean water should always be available. These, like many North American colubrid snakes are an easy species to keep and generally thrive in captivity. I offer my adult animals 1-2 small frozen thawed hopper mice approximately every 7 days, for breeding females I may increase this feeding to once every 5 days prior to and after egg deposition. Occasionally hatchlings need to be offered live prey, or prey that has been altered by transferring lizard scent to it. For the most part though, these kingsnakes will readily accept mammals as a food source without issue.
Captive Reproduction: Variable kings offer no additional hurdles than any other species of kingsnake. I follow the same routine as I do with all North American colubrid snakes. I begin fasting in mid-November for a period of two weeks followed by a gradual reduction in temperature over several days. Then the animals are moved into smaller tubs and transported to my brumation room where the air temperature is allowed to drop into the 40-50 degrees Fahrenheit range. During brumation I regularly change water bowls to prevent dehydration and it is not uncommon for the animals to be periodically active during warmer days while brumating. This period extends into mid-February when the snakes are returned to the racks and the temperatures increased over a period of several days until they are back to a normal temperature fluctuation. At this point I begin offering prey, typically increasing the availability for females I intend to breed that season. After two weeks (or as soon as the female sheds after brumation) I begin pairing adults. Copulation and courtship behavior may not immediately be evident with these shy snakes but even if it isn’t observed I continue to introduce adult pairs every few days for a few hours at a time until I’m satisfied that the female has been fertilized. I provide the female with a laying box, I use size appropriate Rubbermaid food storage containers with an access hole cut into the side or the lid filled with very slightly damp sphagnum moss. The female will most likely spend more and more time in the laying box as she approaches her laying date. Typically 50-60 days after breeding the female will deposit 4-8 eggs, it is important to remove these quickly. I have had females that after laying, will exit the laying box, return to it and begin feeding on eggs. The eggs can be incubated in course vermiculite mixed with water at a 1:1 ratio by weight for 55-70 days at a temperature of 80-83 degrees.