Small rodents offset 29% of the kangaroo rat energy index on nine Portal plots in 2021–2025

We tested whether low rodent compensation continued after a study that ended in January 2020. We used PortalData release 6.117.0. We compared four control plots with five kangaroo rat exclosures. We kept complete censuses and records with the quality-check flag set to one. The energy index was the sum of 5.69 times body mass in grams to the power 0.75. Compensation was the excess small-granivore index on exclosures divided by the control kangaroo rat index. In 42 censuses from June 2021 to September 2025, compensation was 29.0%. The 95% calendar-year bootstrap interval was 17.8% to 40.9%. The comparable estimate for July 1997 to December 2009 was 49.4%. The later-minus-earlier difference was −20.4 percentage points, with a year interval of −36.0 to −5.8 points. With both plot and year resampling, that interval widened to −48.2 to +8.0 points. Thus the point estimate was lower, but plot uncertainty limits the change claim. Bailey’s pocket mouse supplied most of the later compensation. Biomass and capture-count estimates were 25.7% and 43.4%. Removal of exact repeated source rows had little effect. The package contains source data, provenance, code, figures, results and an independent CSV reconstruction. The result describes catch indices at one site, not measured ecosystem energy flow.

functional compensation · rodents · Portal Project · species removal · biodiversity · energy index · reproducibility · plot uncertainty