Date of Award

2026

Document Type

Open Access Master's Thesis

Degree Name

Master of Geographic Information Science

Administrative Home Department

College of Forest Resources and Environmental Science

Advisor 1

Jared D. Wolfe

Advisor 2

Mike D. Hyslop

Committee Member 1

Mickey P. Jarvi

Abstract

Many eastern North American migratory songbirds are declining at alarming rates, and growing evidence suggests that events occurring away from the breeding grounds, particularly during migration, can be major drivers of these trends. Stopover sites are a key component of migration because they are where birds rest, refuel, and recover before continuing long-distance movements, yet the ecological factors that shape how broadly different species use stopover habitat remain unresolved. From both an applied perspective, identifying habitat attributes associated with use by the greatest diversity of migrants will help land managers prioritize and restore stopover sites, actions that may contribute to reversing ongoing population declines.

Here, we examined spatial and seasonal variation in migratory bird species richness across stopover sites in Michigan’s western Upper Peninsula. We interpret richness as a cumulative, community-level signal of habitat use emerging from many individuals across multiple species selecting or avoiding patches during short stopover windows. We paired standardized bird banding data with detailed measurements of forest structure, vegetation composition, and food resources, including invertebrate biomass and fruit availability, and evaluated relationships using hierarchical Bayesian models. Across seasons, higher migratory bird richness was most consistently associated with structurally complex, soft edges, dense understory conditions, relatively open canopy structure, and elevated arthropod biomass. Seasonal patterns were also evident, with spring richness more strongly linked to easily accessible, open foraging conditions and fall richness showing stronger associations with food-rich habitat, consistent with seasonal shifts in resource availability and foraging strategies. Collectively, these results provide a mechanistic basis for restoring and maintaining stopover habitat in ways that maximize use by a diverse migratory assemblage, and they highlight specific structural and resource attributes that can be monitored and targeted to increase functional stopover habitat availability across fragmented landscapes.

Included in

Ornithology Commons

Share

COinS