Does food abundance explain altitudinal migration in a tropical frugivorous bird?
Bibliographic record
Abstract
Many animals undergo annual migrations. These movements are well studied at proximate levels, but their fundamental causes are poorly understood. Among tropical frugivorous birds, annual migration is thought to have evolved in the context of exploiting reciprocal peaks in fruit abundance among locations and seasons, yet previous tests of this hypothesis have yielded equivocal results. In this paper, I tested whether protein and (or) fruit limitation explain both uphill and downhill migratory movements in a tropical frugivorous bird, the White-ruffed Manakin ( Corapipo altera Hellmayer, 1906). While White-ruffed Manakins likely migrate uphill to exploit peaks in fruit abundance, I found no evidence that elevational differences in fruit abundance explain the downhill portion of the migratory cycle. This result challenges long-standing ideas regarding the causes of altitudinal migration because it implies that birds seeking to maximize fruit intake should remain sedentary at higher elevations. Data are also inconsistent with the hypothesis that White-ruffed Manakins migrate (either uphill or downhill) to exploit arthropod prey. Future studies should consider how variation in weather, predators, or parasites could help explain altitudinal migrations of birds from breeding areas to nonbreeding areas.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".