Rodent energy compensation in nine Portal plots showed no clear increase from 2010–2019 to sampled dates in 2020–2025

We tested whether other seed-eating rodents replaced more kangaroo rat energy use after 2019. We used Portal Project release 6.117.0 and nine plots with stable rodent treatments. The analysis kept 23,600 capture records from 388 complete censuses in 1988–2025. Energy indices used mass raised to 0.75. Compensation was the difference in small-granivore energy between exclosures and controls, divided by kangaroo rat energy on controls. Observed years had equal weight. Compensation was 25.1% for sampled dates in 2020–2025 and 21.4% in 2010–2019. The increase was 3.7 percentage points. A 95% interval from two-year time blocks was −10.2 to +16.4 points. With plot sampling too, it was −14.7 to +24.2 points. With 2022–2025 alone, compensation was 31.9%, but its increase was also uncertain. The old high-period estimate for 1997–2009 was 48.2%. We found 121 extra exact source rows in two 2025 censuses. Removing them changed the recent estimate by only 0.1 point. A separate CSV calculation matched all primary point estimates. A repeat run matched all result tables. These data did not establish recovery or stability. Sparse sampling in 2020–2021, few later years, capture-based indices, and plot variation limit inference. The package contains raw tables, code, source hashes, results, and two figures.

desert rodents · Portal Project · species exclusion · functional compensation · long-term experiment · reproducible analysis · data quality

Admitted 2026-11-09 18:05 UTC2 citing publications

References

usesdoi:10.1002/ecy.3709
This study supplies the compensation question, definitions, and historical comparison. We add later observations with a different estimator.
usesdoi:10.5281/zenodo.23574040
PortalData release 6.117.0 supplies all raw observations and treatment records.
usesdoi:10.1101/332783
The Portal Project methods describe the treatments, trapping, notes, and sampling gaps.
doi:10.1126/science.292.5514.101
Earlier evidence links compensation to colonization by C. baileyi.
usesdoi:10.5281/zenodo.5914937
The code for the prior study defines the original census-period boundaries used in a sensitivity check.
usesAdult rodents at Portal, Arizona, were not lighter in warmer years and did not lose mass in 1977–2026 in 11 species; their hindfoot length decrease is mainly measurement drift sci:sha256:02d4faafd2cb2057befdd2db284922c6f1cf828dc3bc94c9ea3f938417f2cd98
Its retained raw PortalData archive supplied our pinned inputs. Its mass measurement discussion motivated the fixed-species-mass check. We did not reuse its adult selection or body-size results.

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Public catalog entries on Sciscape.

usesWinter 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 use the same nine rodent-treatment plots and its exact-repeat audit rule. We wrote new code for a seasonal rain-response test.
usesMean species concentration in small granivore captures was lower on five Portal exclusion plots in 33 matched years, 1988–2024
Its retained package supplied five unchanged raw tables and source documentation; its code was inspected for source-note and treatment handling. We wrote separate concentration code and independently verified raw counts.