Avian Community Response to Oak Savanna Management in West Michigan

In the midwestern United States, oak savanna ecosystems have experienced steep declines over the past century due to loss of disturbances and changes in land use. This loss coincides with the decline in avian communities across North American and has negatively impacted taxa that associate with open vegetation cover types. Expanding efforts to restore and manage oak savanna ecosystems has resulted in increased open habitat which has positively impacted these avian communities, resulting in increased species diversity. While numerous studies within the Midwest have observed similar results, there have been no studies in Michigan that have formally assessed the impact oak savanna restoration has on avian communities. Our aim in this study was to examine how avian communities respond to oak savanna restoration and management within the Huron-Manistee National Forest, Michigan, USA. We used avian point count and nested quadrat survey methods to examine avian communities and vegetative characteristics in managed oak savanna and nearby mixed-deciduous forest sites in the summers of 2021 and 2022. We found different avian communities between oak savanna and forest sites. Savanna sites were favored by open-country bird species and were utilized by omnivores, ground foragers, and ground and shrub nesters in response to reduced canopy cover and increased herbaceous ground cover. Forest avian communities maintained high species diversity despite management efforts and forests sites attracted insectivores and had higher proportions of aerial foragers, bark gleaners and tree nesters that preferred the greater canopy cover, tree and snag densities, and woody ground vegetation at these sites. Despite the relatively small patch size (\u3c21 \u3eha) of managed areas, open habitat species were still able to utilize these sites leading to potential colonization of these newly created open areas. However, whether the presence of these species is indicative of colonization and how management would impact species fitness is yet to 17 be determined. Continued management of oak savanna ecosystems in Michigan has the potential to increase the amount of quality open habitat for open-country avian communities as well as other groups of threatened wildlife