Age-based shifts in habitat selection of wild turkey broods

Animals exhibit pronounced age-based shifts in habitat selection, often because of increasing body size. Body size affects how animals access resources, traverse landscapes, and perceive predation risk. While adults may be habitat generalists, offspring may be constrained by diet, predation avoidance methods, and mobility given smaller body size, and thus be more specialized. Observed declines in eastern wild turkey (Meleagris gallopavo silvestris) productivity and recruitment across the southeastern United States has necessitated evaluations of availability and composition of brood habitat. As poults are smaller and have more specialized resource requirements than adults, selection of vegetation likely changes as poults age. We evaluated aged-based shifts in selection relative to vegetation communities, normalized difference vegetation indices (NDVI), and distances to trails by eastern wild turkey brooding females in a pine (Pinus spp.)dominated landscape in Georgia, USA, from April-July during 2017-2020. We used step-selection functions and conditional logistic regression to evaluate resource selection of 36 brooding females. Of 175 nests monitored, 36 (20.6%) successfully hatched a brood and only 12 broods had at least 1 poult survive =28 days post-hatch (i.e., 6.9% of nests produced a poult that was recruited into the population). Overall, brooding females selected for pastures (ss = 0.730; 95% CI = 0.5144-0.9452), hardwoods (ss = 0.324; 95% CI = 0.1608-0.4865), areas closer to trails (ss = -0.002; 95% CI = -0.0023--0.0014), and areas with greater NDVI values (ss = 2.714; 95% CI = 1.7897-3.6380). Habitat selection shifted as broods aged, suggesting resource needs shift to scale allometrically with body size as broods get older. For example, selection strength waned as broods aged and broods were 2.47 times less likely to select pastures on day 28 relative to day 1 post-hatch. Pastures were selected for after broods hatched, whereas selection for young pines increased as poults aged. Despite pine-dominated cover types comprising nearly a third of the usable landscape, young pine communities were avoided by females with recently hatched broods. Managers may create better brood habitat by promoting early successional vegetation communities amidst a diversity of other land cover types to account for changing resource needs and predator avoidance capabilities as poults age.