Renesting Characteristics of Captive Mallards on Experimental Ponds

Renesting characteristics of captive wild-strain mallards (Anas platyrhynchos) were investigated on experimental ponds in southcentral North Dakota during the breeding seasons of 1976-81. Renesting efforts and egg production increased during the 1st 3 years. Post-yearling females that experienced clutch loss during early incubation produced 3 clutches of eggs during the breeding season. All of the birds produced 4 clutches and 50% produced 5 during the study. Birds provided with an unlimited food supply produced an average of 10.36 ± 1.03 (SD), 9.97 ± 1.09 (SD), 9.59 ± 0.91 (SD), 8.47 ± 0.94 (SD), and 8.50 ± 0.50 (SD) eggs during each successive nesting attempt. Clutch size differed (P < 0.01) among birds, ages, and nesting attempts. Renesting intervals for mallard females on unlimited food averaged 7.13 ± 1.24 (SD) days and ranged from 5 to 10 days. Intervals differed (P < 0.01) among birds and interval sequences. When food availability was reduced, renesting intervals increased and clutch size decreased.