Factors Influencing Northern Bobwhite Nest-Site Selection and Fate

Understanding factors underlying nest-site selection is important for effective conservation and management of a declining and economically important species. We measured vegetation characteristics at nest sites of northern bobwhites (Colinus virginianus; hereafter, bobwhites) and at random points in the Texas Panhandle. We used these data to develop a neural network classification model for predicting nest-site suitability. We also compared the characteristics of successful nests with those of failed nests using the bootstrapping method. We monitored a subset of nests using video cameras during incubation and for 3 days postcompletion (succeeded or failed) to determine nest fate, cause of fate, and nest activity after completion. Nest-canopy height, percent shrub cover, and bare-ground exposure were important vegetation characteristics influencing nest-site selection. Sites became more suitable as canopy height exceeded 40 cm, shrub cover exceeded 25%, and as bare-ground exposure fell below 30%. Successful nests had higher canopies and more shrub cover than failed nests, but successful nests had more bare ground than failed nests. Nest visits were common at monitored nests after nest completion (failed, successful). Most visitors were adult bobwhites, but other species also visited nests. Such visits might bias the determination of nest fate if the determination is based on nest remains, especially if nests are not monitored daily. Bobwhites might select nest sites to maximize nest concealment compared with random locations.