Survey temperature gaps had no clear link to recorded bird composition in four US states in 1985-2024

We tested whether larger temperature gaps between annual surveys were linked to larger differences in recorded bird taxa. We used 5,829 consecutive-year pairs from the USGS Breeding Bird Survey in California, Washington, New York, and North Carolina. Each pair had the same route and observer. We fit separate models for two regions in 1985-2004 and 2005-2024, with route-observer and state-year effects and survey controls. Jaccard slopes ranged from +0.085 to +0.427 percentage points per 5 C larger gap. All four intervals adjusted for four tests included zero. The four intervals ranged in total from -0.817 to +1.540 percentage points. Replacement and nestedness-resultant measures also gave uncertain results. All 20 planned Jaccard sensitivity intervals included zero at the individual 95 percent level. These records did not show a clear common positive link. Selected suitable-weather runs, incomplete detection, shared routes, local habitat changes, and approximate cluster inference limit the result. This study does not test climate trends, heat waves, pollution, or true species loss. The package preserves survey inputs, taxon counts, source hashes, code, all results, figures, and raw and offline reproduction checks.

bird composition · survey weather · temperature gap · observation bias · Jaccard dissimilarity · taxon replacement · temporal tests · null result · Breeding Bird Survey