San Diego Mountain Kingsnake - Life History

Life History

Lampropeltis z. pulchra is an infrequently observed, secretive, cryptozooic snake, the life history of which is still only partly understood. The San Diego mountain kingsnake typically emerges from overwintering sites in March and may remain near-surface active through November, but it is particularly conspicuous near the surface from roughly mid-March to mid-May (Klauber 1931, McGurty 1988, Hubbs 2004), during which time it is active during the warmer daylight hours (pers. observ.). Later in the season, it may be active after dark, which is probably related to the fact that, like most snakes, it has a relatively low temperature preferendum and a relatively low critical thermal maximum (42.5 °C: data provided for L. zonata, subspecies not specified; Brattstrom 1965). Based on wild-caught captive individuals, mating probably takes place in May and eggs are usually laid in June or early July (McGurty 1988; pers. observ.). Females lay 4-9 moderate-sized (averages 36 mm long x 16 mm wide), bone white, leathery-shelled eggs that if similar to eggs incubated in captivity, require at least 2 months to develop before hatching (McGurty 1988). Hatchlings are usually first observed between late August and early October (pers. observ.). The time required to reach reproductive maturity in the field is unknown, but captive L. z. pulchra required 4-5 years to reach sexual maturity (McGurty 1988). If captive longevity records for other races of this species are any indication (see Bowler 1977), San Diego mountain kingsnakes may be relatively long-lived. Indications exist that L. z. pulchra may be highly philopatric, consistently using local patches of suitable habitat (McGurty 1988), but the movement patterns of this taxon are largely unknown. In most areas this snake is much more extant than previously believed, and not restricted to rock outcrops. It lives underground, and has been found in rock-less areas utilizing stumps, logs, and artificial cover, such as old boards, tins, concrete, asphalt chunks, and even trash. The only ingredients needed to sustain a population of L. z. pulchra are prey and shelter (Hubbs, 2004). This taxon is also probably primarily saurophagous, and only western fence lizards and Western Skinks have been recorded as having been eaten by San Diego mountain kingsnakes, but prey similar to other subspecies of L. zonata are probably also taken (Newton and Smith 1975, McGurty 1988).