Evidence for a Relationship Between the Movements of the Common Redpoll (Acanthis flammea) and the American Goldfinch (Spinus tristis)
Bibliographic record
Abstract
Background: Many bird species that breed at high latitudes exhibit irregular southward incursions in response to spatial and temporal variation in winter food availability. Methods: We analyzed Christmas Bird Count records to compare the migratory behavior of the Common Redpoll (Acanthis flammea), an Arctic breeder known to invade southern latitudes every other winter, with that of the American Goldfinch (Spinus tristis), a closely related finch species that breeds broadly in temperate latitudes in North America. Results and Discussion: Historic data indicate that east of the Rocky Mountains, both species overwinter in relatively even numbers across latitudes. In contrast, we found few significant positive correlations between the winter records of each species in different areas along the same longitude. We attribute these patterns to the fact that resource levels and environmental conditions tend to be similar across latitudes. While previous studies of historic data have identified a biennial pattern in the migration of the Common Redpoll, we found evidence that populations of American Goldfinches breeding in the northern parts of the species’ range similarly display significant southward movements every other year. Because these two species breed at different latitudes and show large-scale southward movements during the same years, areas across southern Canada and the northern United States alternate between having high winter abundances of Common Redpolls and American Goldfinches. We propose that these alternations are caused by a shared response to cyclical seed crop failure across the northern regions of North America.
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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 | 0.001 | 0.002 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".