The Ovarian Cycle, Reproductive Potential, and Structure in a Population of the Japanese Lacertid Takydromus tachydromoides

Abstract

A three year study of a population of Takydromus tachydromoides in central Honshu, Japan revealed that yolk deposition in follicles of juvenile lizards begins in the late spring following their first hibernation, at a body length exceeding 41 mm. Adult females emerge from hibernation with yolked follicles. Oviposition of first year lizards begins in early June, reaches a maximum in July and ends before mid-August. Older females begin oviposition in early May, reach their peak in the first half of June, and cease laying in late July. In experimental lizards corpora lutea regressed from an average of 2.1 mm on the day of oviposition to 1.0 mm five days postoviposition. These persist as corpora albicantia apparently for the life of the lizard. Estimates of age groupings by counts of corpora albicantia suggests that first year females contain none in spring and 4-13 in fall; second year lizards, 1-12 in spring and 14-26 in fall; third year females, 14-23 in spring and 26-39 in fall; and fourth year females, 31-40 in spring and 51-69 in fall. The incidence of corpora albicantia in adult lizards collected from 15 August until hibernation is 97%. Clutch size of first year lizards ranges from 1 to 4 for all clutches, with means of 2.6 for the first clutch and 2.4 for the second and third. Clutches