Winter rain had no clear link to the spring capture ratio of seed-eating rodents other than kangaroo rats on nine Portal plots, 1988–2025

We tested whether other seed-eating rodents had a greater spring capture advantage on kangaroo rat exclosures after dry winters. We used four controls and five exclosures at Portal, Arizona, with 102 common censuses and 36 observed April–June years in 1988–2025. The response was the log ratio of treatment mean captures with 0.5 added to each mean. The model used October–March county rain, linear time and sampled month. An extra 100 mm of winter rain was linked to a 6.9% lower exclosure-to-control ratio. Its approximate 95% range from 9,999 paired three-year block resamples was 22.0% lower to 8.3% higher. Joint year and plot resampling widened the range to 28.2% lower to 19.8% higher. A later on-site rain check at 30 years was also uncertain. The early 1988–2006 subset had a negative slope; the later subset did not establish a link. These data do not establish equal responses, absence of competition, or lack of help during a specific dry event. Captures are an index, rain is observed, other treatment histories differ, and all plots are at one site. The package has source data, provenance, the local plan, all results, figures, independent count checks and offline repeat instructions.

desert rodents · rainfall · species interactions · Portal Project · long-term experiment · capture counts · null result · reproducibility