SURVIVAL OF NORTHERN BOBWHITE CHICKS IN WESTERN OKLAHOMA

We estimated survival for chicks within 59 northern bobwhite (Colinus virginianus) broods using a modification of the Mayfield method that a llows for brood mixing and intrabrood dependence. Broods were monitore d during 1992-94 oil the Packsaddle Wildlife Management Area in wester n Oklahoma. Daily survival rates (DSR) were calculated for chicks rear ed by both female and male parents, chicks from hatching to 20 days ol d, chicks from 21 to 39 days old, chicks from hatching to 39 days old, by year, and pooled over years. Survival rates of brood mates were de pendent on each other (P < 0.0001); therefore, the entire brood was th e appropriate sampling unit for estimating variation associated with c hick survival. Daily survival rate estimates for chicks in broods rais ed by females and males did not differ. Daily survival rates of chicks less than or equal to 20 days old were not significantly less than DS Rs of chicks greater than or equal to 21 days old. No differences were observed among years for DSR of chicks pooled over sexes less than or equal to 20 days old or chicks greater than or equal to 21 days old ( P = 0.9997). Chick DSR pooled over the entire brood-rearing period ((x ) over bar = 39 days, SE = 4.1 days) did not differ among) ears for ei ther ses or pooled over sexes. Survival estimates pooled over seu and years for chicks from hatching to 20 days old and from 21 to 39 days o ld were 37.9 and 96.8%. The estimate of chick survival pooled over sea and years from hatching to 39 days was 36.7%.