Low rainfall gave no clear change in the next-year bird-count temperature slope in US surveys in 1995-2024

We tested whether low rainfall made the relation between previous May-June temperature and next-year recorded bird counts more negative. We reused a verified public panel of US Breeding Bird Survey records, county weather, and ozone. The main sample had 26,815 surveys on 2,134 routes. We used route-observer and state-year effects and survey controls. The interaction was -0.41 in 100 times log-count units per 2 C and 2 inches less rain. Its 95% interval was -1.02 to 0.21. All four East and West, early and late estimates were negative. All four intervals included zero after correction for four tests. Thus, the test did not establish a common negative interaction. Seasonal averages, coarse county exposure, monitor selection, habitat change, and imperfect detection limit the result. The result does not test heat waves, direct drought stress, or a causal climate-change effect. The package includes the input panel, code, all estimates, a numerical check, source hashes, and a figure.

birds · seasonal temperature · rainfall · ozone adjustment · observation bias · regional replication · null result