We investigated the effect of quail feeders on cause-specific mortality of 910 radio-marked northern bobwhites (Colinus virginianus). Research was conducted from 1 October 1991 through 1 October 1996 on the Packsaddle Wildlife Management Area (WMA) in western Oklahoma. Thirty-two feeders filled with milo were located near the center of every 8.1 haonthe283.3-ha(1.6km X 1.8 km) treatment area. The unfed area was 283.3 ha (1.6 km X 1.8 km). Treatments were separated by a 194.3-ha (1.2 km X 1.8 km) buffer area. Four-hundred-seventy-seven mortalities occurred on the control treatment and 433 mortalities on the feeder treatment. Avian and mammalian predators and hunting were the primary mortality agents. Direct mortality due to weather was low and no birds died from disease. Avian and hunting mortalities pooled over years different among months (P < 0.05). Monthly mortality rates (M) pooled over years differed between adult and juvenile bobwhites during October and November (P < 0.05). Pooled over months and years, mammal, hunting, and unknown mortalities differed between adults and juveniles (P < 0.05). Monthly mortality rates pooled over years differed (P < 0.05) between female (M = 0.069) and male (M = 0.099) bobwhites only in May. During May, avian mortality was higher (P < 0.05) on males (M = 0.047) than females (M = 0.020). Pooled over years, mortality differed (P < 0.05) between the control and feeder area during January, February, and December. Cause-specific mortality rates were similar (P > 0.05) when pooled over months and years. Mean annual mortality rates were 82.1% on the control area, 79.0% on the feeder area, and 80.2% pooled over areas. Supplemental feeding did not have an effect on annual bobwhite mortality, but did affect the distribution of cause-specific bobwhite mortality.