The Blue Belly Lizard is scientifically identified as the Western Fence Lizard, or Sceloporus occidentalis. This species is a member of the spiny lizard family and is widely distributed across western North America. The Western Fence Lizard is an oviparous species, meaning females reproduce by laying eggs rather than giving live birth.
The Reproductive Strategy of Western Fence Lizards
The reproductive cycle is characterized by the female laying eggs. Breeding occurs during the spring, with courtship and mating typically observed from March into early summer. Females are capable of producing multiple clutches of eggs throughout the season.
A female generally produces between one and three clutches annually, depending on her size and local environmental conditions. Clutch size is variable, but a female may lay anywhere from 3 to 17 eggs in a single clutch, with an average of about eight eggs being common.
The reproductive period for egg deposition spans from late spring, around April or May, through July. Larger females at lower elevations may produce more clutches and larger clutch sizes. These eggs are white, leathery, and oval, measuring about 14 millimeters long.
Identifying the Blue Belly Lizard
The nickname “Blue Belly Lizard” originates from the distinctive coloration on the underside of adult males. These lizards display bright blue patches on their abdomens and throats, which are used primarily for territorial display and attracting mates during the breeding season.
Adult Western Fence Lizards typically reach a total length of about 8 inches, including the tail. The dorsal coloration is highly variable, ranging from tan to brown or black, often with wavy dark stripes or bands across the back. The scales on this lizard are notably pointed and keeled, giving the reptile a spiny texture.
The geographical range of Sceloporus occidentalis is concentrated in Western North America, encompassing California, Oregon, Washington, Idaho, Nevada, and parts of Utah and Arizona. They thrive in various habitats, including grasslands, woodlands, and chaparral, often seen basking on rocks, logs, or fence posts.
Nesting Locations and Hatchling Development
Female Western Fence Lizards select and prepare nesting sites to ensure offspring survival. The eggs are typically laid in loose, damp soil within shallow cavities the female digs herself. Preferred locations include secluded spots beneath rocks, logs, or leaf litter, which helps maintain stable temperature and moisture.
The eggs undergo an incubation period lasting approximately 60 days. Successful development relies on environmental factors, as the surrounding temperature and moisture levels influence the speed of incubation and the health of the developing embryos. Hatching generally occurs from late July through August, depending on the local climate.
Upon emergence, the hatchlings are miniature versions of the adults, measuring about 1 to 2 inches in snout-to-vent length. They are precocial, meaning they are active and independent immediately after hatching.