Behavioral differences in wild and pen-raised northern bobwhites foraging under risk of predation.

摘要

Northern bobwhites (Colinus virginianus) are an important game species in the southeastern United States. Northern bobwhite populations have been declining steadily over the past 70 years, due mainly to habitat loss. As a solution to reduced wild populations, landowners have released pen-raised quail to augment populations, mostly for hunting purposes. Several studies have shown that pen-raised quail have much higher mortality rates than do wild quail, which may be due to a lack of anti-predatory behaviors.;The overall goal of this research was to assess the behavioral differences between wild and pen-raised quail foraging under risk of predation. Specific objectives were to evaluate the hypothesis that wild quail are more sensitive to predation risk than pen-raised quail and determine the relative contributions of time allocation, vigilance, and foraging efficiency in avoiding predation among wild and pen-raised quail.;This research was conducted in a captive situation at the Tennessee Technological University aviary facility, using pen-raised quail obtained from a local breeder and wild quail captured in central Tennessee. Coveys of four quail were presented with three food patches (safe, moderate risk, high risk) at varying distances from cover in 10-hour trials. Giving up density of each patch was measured to assess sensitivity to predation risk in, and away from, cover. Vigilance, time allocation, foraging efficiency, and two other variables were measured and/or calculated from video recordings for each patch, and were compared between quail types (wild versus pen-raised) and patch risk levels.;Both wild and pen-raised quail preferred to forage in safe patches rather than riskier patches, and vigilance rates were similar between wild and pen-raised quail. However, pen-raised bobwhites spent considerably more time foraging in patches than did wild bobwhites, and pen-raised bobwhites were more willing to visit risky patches. Wild quail foraged more efficiently than did pen-raised quail, and efficiency of wild quail foraging increased dramatically in risky patches. Greater foraging efficiency and associated shorter foraging time among wild quail may make them less susceptible to predation than pen-raised quail.