Using Stable Hydrogen Isotope Analysis of Feathers to Delineate Origins of Harvested Sandhill Cranes in the Central Flyway of North America
Bibliographic record
Abstract
— Assignment and quantification of breeding production areas of migratory birds is a crucial step in understanding their population dynamics and informing conservation and management decisions, especially for game birds. Sandhill Cranes ( Grus canadensis ) breed throughout the North American boreal, taiga, and non-forested regions of the Arctic and Siberia. Birds harvested in North America originate from these remote northern regions but conventional mark-recapture techniques cannot readily be used to answer key questions of proportionate take due to the logistical impossibility of marking young birds in an unbiased way. We used stable-hydrogen isotope analyses ( δ D) of feathers from 242 hatch-year (HY) and 628 after-hatch year (AHY) cranes harvested during the 2002 and 2003 hunting seasons in Saskatchewan, North Dakota, Kansas, Oklahoma, and Texas in order to provide new quantitative information regarding their geographical origins. While adult cranes originated from throughout the breeding range, south of the tree line, most birds were produced in the southeast boreal of western Ontario and/or central Manitoba and/or western Alaska. Adult birds taken in Saskatchewan, at the northern portion of the collection area, showed more northwesterly origins than birds taken at the southernmost extreme in Texas. Isotopic analysis of claws and feathers from individuals showed good correlation suggesting that claws could also be used to delineate latitude of origin, especially for AHY birds that may retain some flight feathers for more than one year. Future studies need to consider more carefully the potential contributions of southern boreal populations and if possible to develop means to distinguish isotopically those birds originating in western Alaska. Received 25 January 2006, accepted 18 April 2006.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".