Ozone data coverage gave no clear change in local warmth-richness slopes in US bird surveys in 1995-2024

We tested whether a pollution data join changed a climate association. We used 64,075 accepted US bird survey visits from 1995-2024. Coverage required current spring and prior summer ozone values from monitors within 50 km. Four East and West, early and late models compared recorded species responses to seasonal warmth, with route-observer and state-year controls. Covered minus uncovered local slopes ranged from -0.453 to +0.779 species per 5 C. All four corrected intervals included zero. Three sensitivity checks gave the same broad null result. Thus, we did not establish a repeated change in the warmth-richness link with ozone data coverage. This does not show equal slopes or random missing data. Wide intervals, roadside sampling, changing detection and coarse climate data limit inference. The package includes the verified input panel, code, source hashes, all estimates and a figure.

observation bias · ozone · biodiversity · seasonal warmth · missing exposure · Breeding Bird Survey · null result