Howland, Brett2024-06-052024-06-052024-04https://hdl.handle.net/11299/263680University of Minnesota M.S. thesis. April 2024. Major: Integrated Biosciences. Advisor: Alexis Grinde. 1 computer file (PDF); v, 62 pages.The Golden-winged Warbler (Vermivora chrysoptera) is one of the most critically threatened birds in North America with a global population estimated at only 400,000 individuals of which 50% nest in Minnesota. The species relies on two distinct habitat types, shrub wetland and young forests, for breeding. Quantifying differences in demographic parameters, such as productivity and survival, between habitats is necessary to inform conservation efforts and ensure long-term population stability and growth. To better understand the breeding ecology of Golden-winged Warblers, we studied their nest success, post-fledging survival, and post-fledging habitat-use across 10 study sites in northern Minnesota, USA from 2020 to 2023. We monitored a total of 91 nests and tracked the post-fledging movements of 60 individuals from 52 broods. We used these data to determine the influence of vegetation characteristics, habitat, and landscape factors on nest success, fledgling survival, and post-fledging habitat-use. We assessed the effect of habitat type on nest and juvenile survival using a Markov likelihood framework to estimate daily survival rate as well as daily failure probabilities due to predation and weather events. Our results indicated that there was no difference in nest success and fledgling survival between young forests and shrub wetlands. Predation by sciurids, hawks, and mesocarnivores during the nesting period and the post- fledging period was the most common cause of mortality. Nest survival was lowest for nests that were close to forest edges and survival was lower for nests that were initiated later in the breeding season. Fledgling survival was also lower for birds near forest edges but increased as fledglings aged and became more mobile. Results from the habitat selection models indicated that Golden- winged Warbler fledglings used a variety of habitats including young forest stands that have retained trees and shrub wetland habitats; within stands, they select for areas with high shrub/sapling density, canopy cover, and coarse woody debris. Overall, our results showed that forest management activities that promote structural diversity in young forest stands and conservation of shrub wetland habitats is necessary to maintain stable breeding populations of Golden-winged Warblers in the region.enBreeding HabitatGolden-winged WarblerNest SurvivalPost-fledgingShrub WetlandThesis or Dissertation