Hypoxia Probably Does not Explain Short Incubation Periods of Woodpeckers
Bibliographic record
Abstract
Abstract I tested the hypothesis that hypoxia in tree cavities causes the unusually short incubation periods characteristic of woodpeckers. I compared saturated O2 levels in ambient air to O2 levels in 13 unoccupied and 14 occupied nest cavities of the Northern Flicker (Colaptes auratus). Oxygen in unoccupied cavities did not differ from ambient levels, whereas O2 in cavities with an incubating adult was 2.2% lower than in saturated air. However, the magnitude of the decrease (20.5% oxygen in occupied cavities compared to 21.0% O2 in saturated air) is small compared to variation in the partial pressure of O2 caused by altitude. This suggests that O2 depletion is not a major selective force on embryonic development times for birds nesting in tree cavities. Alternative hypotheses for short incubation periods of woodpeckers include sexual selection on females and sibling competition.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".