Reproduction in Mountain and Lowland Populations of the Lizard Sceloporus occidentalis

Reproductive cycles of mountain (San Gabriel 1584 m) and lowland (Whittier 150 m) populations of the western fence lizard Sceloporus occidentalis were investigated. Spermiogenesis begins February at low elevations and is delayed six weeks until early April at high elevations. Testicular regression occurs in both populations during July. Autumn recrudescence is completed earlier in the mountains than at low elevations. The first low elevation female with oviducal eggs was collected in early April; at high elevations oviducal females did not appear until late May and are present in both populations until mid-July. Low elevation females probably lay 1-3 clutches of eggs; high elevation females 1-2. Young appear in early July at low elevations as opposed to mid-August in the mountains.