Four-state bird records gave uncertain negative wind slopes in matched surveys from 1990-2024

We tested whether higher survey wind was linked to fewer recorded bird taxa in California, Oregon, New York, and Pennsylvania. We used 7,068 consecutive-year pairs from the same route and observer. We fit separate models in two regions and two periods. We adjusted for survey temperature, date, time, duration, sky, assistant status, observer experience, and state-year effects. All four slopes were negative. They ranged from -0.33 to -0.22 recorded taxa per one-code increase in mean start and end Beaufort wind. No slope excluded zero after correction for four tests. All corrected intervals were within -0.73 to +0.25 taxa. Four planned sensitivity checks also gave negative point estimates in each region and period, with corrected intervals that included zero. This is a weak common pattern in accepted survey weather. It does not establish a wind effect or separate detection from ecological change. The wind scale is ordered and does not measure equal speed steps. Selection, missing fields, roadside samples, model form, and shared shocks across routes limit inference. The study does not test extreme weather, air pollution, or long-term climate effects. The package includes source hashes, selected records, code, model designs, checks, and offline instructions.

birds · weather · wind · observation bias · Breeding Bird Survey · recorded taxa · null result