Record Details

Abts, Marvin L
Reproduction in the saxicolous desert lizard, Sauromalus obesus: the female reproductive cycle
Journal Article
Sauromalus obesus
Aspects of reproduction were examined in female chuckwallas, Sauromalus obesus, as part of a 7 yr life history study. Size and age at reproductive maturity were 125 mm snout-vent length (SVL) and 2 yr, respectively. Females exhibited year round oocytogenesis and postovulatory vitellogenesis. Clutch size (x = 6.9) was highly correlated with body size and showed remarkable consistency among years for a given body size. Corpora adiposa were largely devoted to reproduction. Post-oviposition females were able to regain considerable mass by feeding in late summer. Hatchlings were routinely observed in early fall. The timing of advanced stages of ovarian and uterine cycles always occurred from mid-June - mid-July. Extremely precise oviposition, always occurring just prior to summer rainfall, probably minimizes egg susceptibility to desiccation. Adult female chuckwallas appeared to demonstrate a similar annual precision in oviposition and consistency in clutch size throughout much of their geographic range.