Prior summer rain had no clear common link to relative Ringlet growth in England and Wales in 1984-2024

We tested whether low summer rain was linked to lower annual Ringlet growth relative to Meadow Brown in the next year. We used 82 country-year growth records in England and Wales in 1984-2024. Four country and period models controlled current summer rain, current and prior summer temperature, and a linear time term. Estimates were -1.7%, -11.2%, +7.2% and -22.9% per 100 mm less prior summer rain. All four corrected uncertainty intervals included zero. Later point estimates were negative in both countries, but a common decline was not established. A 20-site check retained only one early Wales year. Changing the weather window also changed the early Wales sign. The result concerns relative annual growth, not absolute abundance or a lower next-year level. Country weather, short series, changing sites, detection and missing source-index uncertainty limit inference. We did not estimate a causal climate or pollution effect. The package includes exact source snapshots, code, source hashes, all model results, figures and offline checks.

butterflies · rainfall · relative annual growth · drought · observation bias · UKBMS · Ringlet · Meadow Brown · regional replication · null result