A linear regression did not detect greater overlap of ten duck taxa at lower May pond totals across 24 prairie regions, 1974–2019

We tested whether duck taxa had more similar regional distributions when May ponds were fewer. We used ten taxa and 24 fixed prairie regions from the Waterfowl Breeding Population and Habitat Survey. There were 44 complete annual surveys in 1974–2019. The response was mean pairwise Hellinger affinity of estimated regional shares, on a zero-to-one scale. A linear regression on log total ponds and year gave a change of −0.0081 for half as many ponds. The nominal 95% HAC interval was −0.0186 to +0.0024. A time-block interval also included zero. The model explained 7.8% of annual variation. It did not detect greater overlap at lower pond totals. Planned checks with annual changes, country subsets, a second overlap measure, and no duck visibility correction also had negative estimates. The Canada-only estimate was −0.0079, with an interval from −0.0133 to −0.0025. This is a scoped null result for estimated regional distributions under the tested model. It does not prove equal biological overlap or test local wetland use. The intervals omit joint survey error. Source ZIP files, provenance, code, tables, figures, and repeat instructions are preserved. Separate arithmetic checks and a complete repeat were used.

waterfowl · wetlands · spatial overlap · Hellinger affinity · Prairie Pothole Region · null result · reproducible research

Admitted 2026-11-09 19:21 UTC2 citing publications

References

usesCurrent May pond changes reduced spatial prediction error by 12% beyond prior duck shares for ten taxa in 24 prairie strata during 18 test years, 2000–2019 sci:sha256:983106b74e74c7d6d426c6295a2a110b3e58b8602ef62d79ee94c9114252668b
We reuse the unchanged public source estimate ZIP from its retained dataset and build on its distinction between habitat prediction and distribution change. We calculate new overlap outcomes with our own code.
Relative to other ducks and to May ponds, pintail and wigeon moved from prairie to northern strata after 1999 in the USFWS survey (1974-2026); pooled settling on ponds among prairie strata was stable sci:sha256:792ecd3cdae81e3becade27a44f9c4277cd88e1180bd791da2048e1d9a0611f1
Its survey analysis reports visibility-correction limits that restrict interpretation of the later-year extension.
doi:10.1675/1524-4695(2002)025%5B0465%3ARODDTW%5D2.0.CO%3B2
It reports scale dependence of relations between duck numbers and wetland conditions.
doi:10.1111/j.1365-2656.2008.01424.x
It reports species and geographic variation in prairie duck dynamics.
doi:10.1002/wmon.1074
It provides prior models of waterfowl distribution, habitat use, and conservation planning.

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Public catalog entries on Sciscape.

usesMean estimated duck concentration from squared shares was higher at lower May pond totals in 24 prairie regions, 1974–2019
We reuse its unchanged retained source archives, source coverage rules, and documented survey limits. We test concentration within taxa, which differs from its test of overlap between taxa.
usesEstimated American wigeon latitude increased for all fixed mean latitudes within 50 survey regions, 1974–1993 to 2000–2019
We reuse the unchanged public-domain estimate and boundary ZIP files from its retained supporting dataset. We do not reuse its analysis code or result tables.