Seasonal changes in the ventilatory response to hypoxia in migratory sparrows and an introduced resident sparrow
Bibliographic record
Abstract
Recent research has shown that songbirds that reside at low altitudes can ascend to ∼6000 m above sea level during migratory flight. Since migratory flight is aerobically demanding, whether migratory songbirds exhibit plasticity in breathing to maintain oxygen uptake in low-oxygen environments is unknown. This study investigated whether the hypoxic ventilatory response of sparrows was altered between resident house sparrows ( Passer domesticus (Linneaus, 1758)) and migratory song sparrows ( Melospiza melodia (A. Wilson, 1810)), and Lincoln's sparrows ( Melospiza lincolnii (Audubon, 1834)) or seasonally (long daylight versus short daylight length) within a species. Breathing responses were assessed by stepwise reductions in inspired O2 tension, 21, 16, 12, 9, 7, and 5 kPa during long and short days. Ventilation increased in hypoxia in all species, although song sparrows and Lincoln's sparrows exhibited greater increases in ventilation in severe hypoxia compared to house sparrows. All species became more sensitive to hypoxia during short days compared to long days (increased breathing frequency and total ventilation), with reduced pulmonary oxygen extraction. Although all sparrows had similar ventilatory responses in moderate hypoxia, our findings suggest that migratory sparrows breathe more effectively in severe hypoxia compared to house sparrows, which would be important for maintaining oxygen uptake during migratory flights.
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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 | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".