Most copulations occur in spring and late summer-early fall. Births occur mainly in August or September in most areas, but may occur as early as July or as late as November in some areas. In Kansas, individual females evidently give birth usually in alternate years, July-early October; males sexually mature in 2nd summer, most females in 3 years (Fitch 1960). In southern Texas, individual females may produce young in consecutive years (Vermersch and Kuntz, 1986, Snakes of south central Texas, Eakin Press, Austin). Litter size up to 21 (most often 4-8) in east and north, average of 5.3 in Kansas, usually not more than 3-4 in Trans-Pecos subspecies PICTIGASTER.