Conditioning effect on survival of foster parents of reintroduced masked bobwhite broods

Recovery efforts for endangered masked bobwhites Colinus virginianus ridgwayi rely on the reintroduction of captive-reared birds. Using foster parents to brood and escort chicks as they gain experience has been more successful than hard releases of older pen-reared juvenile or adult masked bobwhites. Survival of foster parents likely has implications for survival of chicks that become the founding population. Pre-release conditioning influences survival of foster parents. We compared survival of foster parents with differing histories to inform management decisions. Foster parents were from 3 sources: captive masked bobwhites from (1) an indoor flock and (2) an outdoor flock, and (3) wild northern bobwhites C. v. taylori . We radio-tagged 129 foster parents and bonded them with chicks prior to release. Our results indicated that survival at 120 d post-release of wild birds was 1.6-1.9 times greater than of outdoor conditioned birds, and indoor birds had the lowest survival (<0.08). Daily survival probability increased as day since release increased, indicating acclimation to their new environment. Extremely low survival (<0.02) of any foster parent types in 2020 was likely due to severe drought conditions. Wild birds exhibited advantages over the other 2 types of foster parents by showing greater survival even as drought conditions worsened and a greater proportion of overwintering juveniles in coveys over the course of the study. Improvements in conditioning by modifying reintroduction efforts for masked bobwhites such as providing longer outdoor experience for captive birds or the use of wild foster parents should increase survival in favorable years.