Lampropeltis zonata
California Mountain Kingsnake

Lampropeltis zonata, or California mountain kingsnakes, range from an isolated population in south-central Washington and adjacent northern Oregon, to southwestern Oregon, south along the coastal and interior mountains of California in the United States, to northern Baja California, Mexico. It is also present in numerous scattered populations within its Californian range. ("IUCN Red List of Threatened Species: Lampropeltis zonata", 2010; Ernst and Ernst, 2003)

Lampropeltis zonata is found in a wide variety of habitats and is considered a habitat generalist. Most often though, it is associated with moist woodlands such as coniferous forests, oak woodlands, chaparral, or coastal sage scrub. In these areas, it is commonly located within riparian zones with ample rocks and rotting logs where the sun reaches, or on the south-facing, rocky, slopes of stream canyons. They inhabit elevations ranging from sea level to 3,000 m above sea level. ("California Reptiles and Amphibians", 2010; Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Stebbins, 2003)

Lampropeltis zonata can reach a total body length of 122.5 cm, although most are shorter than 100 cm long. There are 21 to 23 dorsal body scale rows at mid-body. The scales are smooth and unkeeled. The venter has 194 to 227 ventrals, 45 to 62 subcaudals, and an undivided anal plate. Each maxilla on this snake has 11 to 13 teeth.

Males have 45 to 62 subcaudals and tail lengths that average 18.2% of total body length, while females have 46 to 56 subcaudals and tail lengths averaging 17.5% of total body length. Other than these differences, sexes are hard to distinguish superficially. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Stebbins, 1954; Stebbins, 2003)

The slender, cylindrical body of this snake is patterned with black, white (or occasionally yellow), and red bands, with the red bands always bordered by black bands on both sides. The black and red bands generally extend onto the white venter, which may be speckled with black marks posteriorly. The dorsal side of the head is black, but the chin and throat are often white. The first band after the black head is white.

There are seven described subspecies, of which five occur north of Mexico. Pattern variation exists especially for the red bands, which may be interrupted dorsally to form a wedge-shaped blotch on each side within a broad black band, or the red pigment may be reduced or even absent altogether (especially in Sierra Nevada populations). Other forms of geographic variation involve variations in the width of the black bands, and the numbers of body triads (one red band surrounded by two black bands) that are present.

Due to the extreme variability of this snake, the described subspecies are difficult to tell apart, and best identified by locality. Intergradation between populations is common, and ranges of subspecies are discontinuous. Identification of subspecies in the northern edge of the range, in Oregon and Washington, is controversial. ("California Reptiles and Amphibians", 2010; Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Stebbins, 1954; Stebbins, 2003)

Lampropeltis zonata is an oviparous species, whose eggs incubate for an average 62 days. After hatching, Lampropeltis zonata young measure 20.0 to 27.2 cm in length, and weigh about 5.7 to 7.7 g. The hatchlings are just as vividly colored as adults. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Stebbins, 2003)

These snakes generally reach maturity at a SVL (snout to vent length) of roughly 45 centimeters. In terms of total body length, however, males reach maturity at 50.7 centimeters, and females reach maturity at 54.7 centimeters. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Greene and Rodriguez-Robles, 2003; Stebbins, 2003)

In the wild, Lampropeltis zonata males may find females by following their pheromone trails. In captivity, males show interest in places where females have coiled or crawled. Little information is known regarding courtship behavior or mating systems for this species. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003)

Lampropeltis zonata typically breeds from April through early June, usually soon after emergence in the spring, although copulation by captives has taken place as early as March. Females may breed only every second year. ("California Reptiles and Amphibians", 2010; Bartlett and Tennant, 2000; Ernst and Ernst, 2003)

Oviposition occurs in late May to July. Clutches average about 7 eggs, but range from 2 to 10. Eggs are white, elongated, and adherent, averaging 42.2 (40.0 to 45.0) mm in length, and 17.2 (15.8 to 18.0) mm in width, with a mass of about 6.6 (5.0 to 9.0) g.

Depending on incubation temperature, incubation periods average 62 days, but range from 47 to 87 days at temperatures of 23 to 29 degrees Celsius.

Age of maturity is unreported. ("California Reptiles and Amphibians", 2010; Ernst and Ernst, 2003)

Parental investment post-oviposition has not been documented for this species.

The lifespan of Lampropeltis zonata in the wild is unknown, however, an individual in captivity was reported to live up to 26 years, 4 months, and 1 day. (Ernst and Ernst, 2003)

A major threat to Lampropeltis zonata is habitat destruction. This is usually associated with urbanization, however, slabs from rock outcrops are also torn off by people searching for this species or other reptiles. This and other forms of rock removal are damaging an irreplaceable facet of the snake's habitat, leading to detrimental effects on populations. Due to this snake's vibrant coloration, collection for the pet trade has diminished populations, as well. ("California Reptiles and Amphibians", 2010; "IUCN Red List of Threatened Species: Lampropeltis zonata", 2010; Ernst and Ernst, 2003)

Lampropeltis zonata is active from late March through early November annually in California. Winters are spent deep in rock crevices or within mammal burrows in a state of hibernacula, although individuals will come out to bask on warm, sunny days if the winter is mild. During the spring and fall, most daily activity is diurnal, however, during the summer this snake becomes crepuscular or even nocturnal in order to avoid high temperatures during the day. ("Santa Barbara Zoo: Animals", 2009; Ernst and Ernst, 2003)

Lampropeltis zonata is a good climber. One individual was found over 1.5 meters above ground coiled in a decaying cavity of an oak tree. This snake generally has secretive habits, spending most of its time underground, under surface objects, or inside rock crevices. ("California Reptiles and Amphibians", 2010; Ernst and Ernst, 2003; Stebbins, 1954)

The home range size of Lampropeltis zonata is unknown.

Lampropeltis zonata uses sight to locate moving prey, and smell (olfaction and the vomero-nasal system) to find hidden prey and eggs. Males will follow pheromone trails to find females during the mating season. They perceive their environments through sight, smell, and touch.

This snake also communicates with other animals through bright coloration that warns potential predators to avoid eating it. Since it is not actually venomous as its colors would suggest, this is possibly a form of Batesian mimicry that mimics an aposematic species. The presumed model species would be the venomous Sonoran coral snakes (Micruroides euryxanthus), an elapid, which does not now occur in the United States portion of mountain kingsnakes' range.

Like all snakes, California mountain snakes possess primitive ear structures that allow them to detect vibrations. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003)

As an active hunter, Lampropeltis zonata uses sight and olfaction to find its prey. Once caught, small or helpless prey are swallowed immediately, but large, struggling prey must be constricted before ingestion. Food items are swallowed head-first the majority of the time.

Lizards including Gilbert skinks (Plestiodon gilberti), western skinks (E. skiltonianus), sagebrush lizards (Sceloporus graciosus) and western fence lizards (S. occidentalis) are common prey. Nestling bird species such as Swainson's thrushes (Catharus ustulatus), dusky flycatchers (Empidonax oberholseri), and green-tailed towhees (Pipilo chlorurus) are other important prey of this snake. Lizard eggs, bird eggs, small snakes (prairie rattlesnakes Crotalus viridis), small mammals, and possibly amphibians are all eaten as well. ("California Reptiles and Amphibians", 2010; Bartlett and Tennant, 2000; Ernst and Ernst, 2003; Greene and Rodriguez-Robles, 2003; Stebbins, 1954)

The bright coloration of Lampropeltis zonata is believed to aid its hunting by making it more conspicuous to prey species. Birds will often attack this snake as they see it approach their nests. This allows the snake to follow the cues of intensity and directionality of the attack to search for bird eggs and nestlings. (Ernst and Ernst, 2003)

No acts of natural predation on Lampropeltis zonata have been reported. Certainly it is vulnerable to a variety of predatory mammals and birds. Although this snake is nonvenomous, its bold and advertising pattern has been considered a mimic of venomous coral snakes, such as Sonoran coral snakes (Micruroides euryxanthus), therefore warding off potential predators.

When faced with danger, flight is the first defense of Lampropeltis zonata and it will crawl to cover when given the chance. If this is not possible, it may coil and strike its attacker. When handled, it will twist violently to escape, release musk and fecal matter, and bite viciously with teeth that can cause rather deep lacerations. (Bartlett and Tennant, 2000; Ernst and Ernst, 2003)

Lampropeltis zonata is a key predator in its ecosystem and presumably helps regulate the populations of its prey. (Ernst and Ernst, 2003)

Lampropeltis zonata is often collected for use in the pet trade due to its attractive coloration and lack of venom. Its use in zoos also allows for the education of visitors about this snake and others. Captive breeding can reduce the market for wild-caught animals. ("California Reptiles and Amphibians", 2010; Ernst and Ernst, 2003)

This species does not cause any harm to humans or their interests. In the presence of danger, its first response is to flee and will only strike when absolutely necessary. Despite its bright coloration, it is nonvenomous and is simply a mimic of poisonous species. (Ernst and Ernst, 2003)

Lampropeltis zonata is currently listed as a California Species of Special Concern, according to the California Department of Fish and Game, and some populations are protected. Oregon protects this species. The IUCN Red List labels it as of Least Concern.

Habitat destruction associated with urbanization and rock collection are the most frequent threats to this species, but it is also commonly used in the pet trade. Even though some areas are protected habitats, measures to prevent illegal snake collecting are weak. This snake is capable of breeding in captivity, which should be used to fulfill the demand for pets while allowing the native populations to remain undisturbed. ("IUCN Red List of Threatened Species: Lampropeltis zonata", 2010; Ernst and Ernst, 2003)