Quantifying biodiversity outcomes remains one of the greatest challenges in evaluating wetland restoration success. The Bird-Friendliness Index (BFI) was developed as a practical biodiversity indicator that uses bird community composition to assess ecosystem condition by integrating bird abundance, conservation importance, and functional diversity into a standardized metric of habitat quality. Here, we demonstrate application of an adapted marshbird-focused BFI to evaluate wetland restoration outcomes across the Great Lakes region. We highlight two complementary use cases: (1) measuring marshbird response through time following Sustain Our Great Lakes (SOGL) restoration actions; and (2) comparing ecological condition among sites in the Calumet region (Indiana and Illinois). Across applications, the BFI provided an interpretable indicator of wetland bird community condition and allowed restoration outcomes to be evaluated beyond single-species responses. In the Calumet region, restored wetlands exhibited higher marshbird friendliness than sites not yet restored, and longitudinal analyses further illustrate how BFI trajectories can be used to demonstrate positive biodiversity change through time at SOGL-restored sites relative to broader regional variation.
