Resource selection and movement by northern bobwhite broods varies with age and explains survival

Oecologia. 2021 Apr;195(4):937-948. doi: 10.1007/s00442-021-04893-z. Epub 2021 Mar 7.

Abstract

Resource selection is a dynamic process driven by habitat valuation and risk avoidance in heterogeneous landscapes. Resource selection and movement decisions of individuals may be sensitive to intrinsic factors, such as body condition, and variation in these choices may have consequences on subsequent survival. We evaluated northern bobwhite (Colinus virginianus) brood resource selection patterns to quantify utility of different cover types during the development period using integrated step-selection analysis in a Bayesian hierarchical modeling framework with three brood stages: flightless broods ≤ 14 days old, dependent broods 15-35 days old, and independent broods over 35 days old. Broods showed strongest selection for native grasslands that were burned and grazed at least once in the previous two years, and agricultural fields. Brood mobility improved with age; broods > 35 days old travelled farther on average and took daily steps > 200 m more frequently than younger broods. Young broods ≤ 14 days old did not select for idle native grasslands, while broods > 35 days old did select for that cover type. Young broods also selected areas farther from trees compared to older broods. We evaluated the survival consequences of resource selection by comparing patterns in choices of broods that succeeded to choices of broods that failed to survive to 35 days. Successful broods chose habitats with more shrub cover and areas farther from trees compared to failed broods. Our results suggest that conservation planning should consider age-specific patterns in habitat use and demographic consequences of habitat choice for greatest effectiveness.

Keywords: Brood movement; Habitat management; Integrated step-selection analysis; Native grasslands; Resource selection.

MeSH terms

  • Animals
  • Bayes Theorem
  • Colinus*
  • Ecosystem