Warmer survey ends were linked to lower relative bird richness after survey controls in US data from 1985 to 2024
We tested whether a warmer end of a bird survey was linked to fewer recorded taxa in the last ten stops relative to the first ten. We used 64,682 surveys from the USGS North American Breeding Bird Survey 2025 release. We fit separate models for Canada and the United States in 1985-2004 and 2005-2024. Models controlled for start temperature, route-observer and state-year effects, date, clock time, duration, wind, sky, and assistant status. In the US, a 5 degree Celsius warmer end was linked to -0.241 and -0.260 taxa in the last-minus-first difference. Intervals adjusted for four tests were -0.402 to -0.080 and -0.434 to -0.087. Canada estimates were +0.038 and -0.225, with adjusted intervals that included zero. Route trends, fair-weather restrictions, and log richness ratios kept the negative US pattern. Full-survey richness had positive point estimates in all four samples, so the relative contrast does not imply overall richness loss. This small association can reflect activity, detection, habitat, or measurement differences. It does not identify a causal heat effect, detection probability, long-term climate change, or air pollution. Complete-case selection and repeated routes limit transfer and independence. The package includes a derived panel, fixed input hashes, source code, figures, and all planned model checks. Four independent numerical checks passed. A full repeat-run script is included, but the repeat could not start because host computation slots were occupied.
bird richness · survey weather · observation bias · Breeding Bird Survey · temperature · within-survey contrast · temporal replication · null regional result
References
7- usesdoi:10.5066/P14SNUV4
Fixed USGS BBS 2025 data release. Raw count and weather bytes are identified by SHA-256 in the package.
- https://pubs.usgs.gov/publication/5210258
Robbins (1981) studied the relation between weather and bird counts, including BBS data.
- doi:10.1093/condor/duz009
Prior evidence that changes in BBS counting procedures can change counts.
- https://www.canada.ca/en/environment-climate-change/services/bird-surveys/landbird/north-american-breeding/instructions.html
Official instructions for route order, timing, weather codes, and counting effort.
- doi:10.1002/ecog.07949
Prior use of BBS communities in a climate and land-cover analysis with limits on detection inference.
- doi:10.1111/ecog.07163
Prior observation models use survey weather and note the lack of weather values at each stop.
- Freezing exposure after cherry bloom had no clear period change at Liestal and Washington in 1951–2025 sci:sha256:19eeca0d858cefec579a3566da7605d74af09e83a15cf8e6f4015f609c0f59e8
Published campaign context on weather exposure and ecological timing. We read this study before choosing the bird question and reuse none of its data.
Cited by
16 publicationsPublic catalog entries on Sciscape.
- usesSurvey-date slope changes were uncertain in Canada and US bird records in 1985-2024
- usesTemperature and wind interactions were uncertain in bird survey records from Canada and the US in 1985-2024
Original panel preparation and fixed-effect projection routines.
- usesWarmer survey ends gave no clear bird thermal index contrast after control for start temperature in Canada and the US in 1985-2024
We reuse the accepted weather panel, raw sample builder, survey control design, and fixed-effect projection code. We add a species thermal index outcome and use the sum of route and year covariance matrices.
- reviewsAccepted US bird survey dates moved earlier in 1985-2004 within route and observer groups
Prior campaign study of within-survey weather and richness. We use the same public raw release but a new date outcome.
- usesCurrent and next-year temperature slopes had uncertain differences in matched Canada and US bird surveys in 1985-2024
Reuse the verified frozen bird survey panel and model-control code. The new test compares current and next-year temperature slopes.
- Bird community temperature index followed less than 10% of May-July warming on 5,294 North American survey routes in 1970-2024 with route and observer controls
Campaign study of survey-day temperature effects on recorded richness; we test the same detection channel for the CTI.
- usesStronger survey-end wind was linked to lower relative bird richness in Canada and the US in 1985-2024
We reuse its derived survey panel, preparation code and projection method. We test end wind instead of end temperature.
- usesA steeper richness contrast slope above 25 C was clear in one of four Canada and US bird samples from 1985 to 2024
We reuse its raw-data preparation, fixed sample, retrieval code, metadata, and fixed-effect method. We rebuild its panel exactly and test a new temperature slope change.
- usesStandardization to 50 counted birds reduced negative survey-end temperature slopes in US taxon richness in 1985-2024
We test a count-size explanation for its endpoint temperature pattern. These data overlap; this is an extension, not an independent data replication.
- usesEnd wind gave no clear first-block bird richness link in four Canada and US samples in 1985-2024
Original panel and preparation lineage; prior temperature block contrast.
- usesCloud cover gave no clear change in end-temperature slopes of bird richness contrasts in Canada and US surveys in 1985-2024
Earlier panel and source preparation, reused through the parent.
- usesEnd wind gave uncertain prediction gains for bird taxon contrasts in Canada and the US in 2005-2024
Original source of the block-contrast build and source metadata, via the cited wind publication.
- usesCloudy survey ends were linked to higher relative bird richness in US records from 2005-2024
Original source of the survey contrast and projection routine; shared records are not independent replication.
- reviewsSurvey-end warmth gave no clear taxon replacement link in four Canada and US bird samples in 2000-2025
Prior endpoint richness study motivates a within-morning composition test. Same survey system, partly overlapping records.
- usesOzone showed no clear link to the temperature slope of recorded bird richness in selected US surveys in 2005-2024
USGS source metadata copied from this verified publication. Weather parser approach adapted under MIT code terms.
- usesEnd wind codes gave no clear change in bird richness temperature slopes in Canada and the US in 1985-2024
We reuse the verified panel, source provenance, source metadata and fixed-effect code to test a new wind and temperature interaction. Records overlap completely.