Northern Bobwhite juvenile survival is greater in native grasslands managed with fire and grazing and lower in non-native field borders and strip crop fields

Abstract

Abstract Effective species conservation requires understanding environmental effects on stage-specific demographics driving population change. Northern Bobwhite (Colinus virginianus) is an early-successional shrub-obligate species that has experienced long-term, range-wide declines due to fire suppression, agricultural intensification, and sprawling development. Local habitat features and landscape context may interactively influence vital rates. Management affects food, cover, and other resources available locally, while surrounding landscapes often determine degree of isolation and predator communities. We evaluated relationships between juvenile bobwhite survival and local (50 m) and landscape (1 km) scale cover type composition and grassland management (i.e. conservation grazing, prescribed burns, mowing/haying) on 3 native grasslands and 2 traditionally managed conservation areas in southwest Missouri, USA, 2016–2018. We radio-tracked brood-attending adults and young from hatch to a maximum of 114 days and estimated juvenile survival with a Bayesian known-fate logistic exposure model. Juvenile survival was greatest on native grasslands that were burned and grazed at least once in the previous 2 years. Percent shrub cover was positively related to survival. Survival was relatively high in local agriculture, but these relationships were sensitive to surrounding landscape composition. For example, small patches of cropland surrounded by nonagriculture such as strip crops surrounded by grassland units on traditionally managed sites had low survival. Relationships between survival and agricultural landscape cover were dependent on local cover types; survival was high within crop fields but low in non-native grasslands surrounded by crop fields such as agricultural field borders. Patch-burn grazing practices on native grasslands provided the best habitat for bobwhite juvenile survival. Agricultural landscapes can support the recruitment of bobwhite if appropriately managed native grasslands are also available.