Migratory Connectivity of Semipalmated Sandpipers: Winter Distribution and Migration Routes of Breeding Populations
Bibliographic record
Abstract
The Semipalmated Sandpiper (Calidris pusilla) is a small, abundant shorebird that breeds primarily in sub-Arctic to mid-Arctic habitats across the Nearctic and winters principally along the northern and central coasts of South America. No subspecies have been described and little is known concerning their genetics. However, birds show a cline in bill length across the Arctic, with longest bills in the east and shortest in the west. There appear to be several ‘steps’ in the cline, suggesting a division into eastern, central and western breeding populations. Since females average longer bills than males in a breeding population, there is considerable overlap of bill lengths at migration staging areas. Based on bill length patterns and sightings and recoveries of marked individuals, most western breeders migrate south through the prairies, along with some birds from central Arctic populations. The remaining central Arctic breeders, and all eastern Arctic birds, migrate south through the north Atlantic Coast of North America, particularly the Bay of Fundy. Western Arctic breeders appear to winter farther west in South America than eastern breeders, although there is considerable mixing among populations in French Guiana and Guyana. In spring, birds from the eastern Arctic migrate north through the U.S. Atlantic coast, including Delaware Bay. Central and western Arctic breeders primarily migrate north through the interior of North America. Therefore, central Arctic breeders in particular demonstrate an elliptical migration pattern.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 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) | 0.002 | 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".