Data from: Assigning harvested waterfowl to geographic origin using feather δ2H isoscapes: What is the best analytical approach?

Establishing links between breeding, stopover, and wintering sites for
migratory species is important for their effective conservation and
management. Isotopic assignment methods used to create these connections
rely on the use of predictable, established relationships between the
isotopic composition of environmental hydrogen and that of the
non-exchangeable hydrogen in animal tissues, often in the form of a
calibration equation relating feather (δ2Hf)  values derived from
known-origin individuals and amount-weighted long-term precipitation
(δ2Hp) data. The efficacy of assigning waterfowl to moult origin using
stable isotopes depends on the accuracy of these relationships and their
statistical uncertainty. Most current calibrations for terrestrial species
in North America are done using amount-weighted mean growing-season δ2Hp
values, but the calibration relationship is less clear for aquatic and
semi-aquatic species. Our objective was to critically evaluate current
methods used to calibrate δ2Hp isoscapes to predicted δ2Hf values for
waterfowl. Specifically, we evaluated the strength of the relationships
between δ2Hp values from three commonly used isoscapes and
known-origin δ2Hf values from three published and one collected as part of
this study, also grouping these data into foraging guilds (dabbling vs
diving ducks).