Breeding biology of the Great Plains toad in Oklakoma

Bufo cognatus breeding activity was closely associated with precipitation. Consequently, the number of nights when breeding occurred during spring varied considerably from year to year. Breeding occurred for 14 consecutive nights during March 1985, up to six consecutive nights after rainstorms in April and early May but for only one or two nights after June rains. Breeding activity was greatest during the first three hours after sunset and typically during the first two nights after a rainstorm. Regardless of when females entered the breeding pool and paired, egg laying began at sunrise and lasted until mid-morning with amplexus averaging 803 minutes. Bufo cognatus exhibited communal egg laying at seven different breeding sites that characteristically had large breeding choruses. Some 88% of all females in those pools laid eggs at a 1-4m² area specific in each pool. These areas were used from rain to rain and from year to year. Females exhibited size-related fecundity with clutches ranging from 1342-45 054 eggs. Larval period also varied greatly ranging from 45 days in April to 18 days in June. -from Author