June survey dates showed no clear drop in medium or heavy satellite smoke in four US bird samples in 2011-2024

We tested whether accepted US bird survey dates had less mapped smoke than the same weekday one week before and after. We used 13,155 mid-June surveys on 2,943 routes in 2011-2024. Four East and West, early and late samples gave medium or heavy smoke contrasts from -0.36 to +1.62 percentage points. All marginal and four-test intervals included zero. Other smoke categories and date windows gave no clear common reduction. Published daily smoke data reproduced every matched exposure. A current raw survey register confirmed all planned survey dates and route keys. The result does not establish that observers ignore smoke. Reference dates can be unsuitable or unavailable, satellite smoke can be aloft, and few year clusters limit uncertainty estimates. We do not measure a bird response or a causal climate effect. The package gives the matched data, code, source hashes, all estimates, figures and offline reproduction instructions.

wildfire smoke · observation bias · survey timing · Breeding Bird Survey · matched dates · satellite smoke · null result · regional replication