Age- and Sex-Related Variation in Song-Control Regions in Cassin’s Finches, <i>Carpodacus cassinii</i>
Bibliographic record
Abstract
Male Cassin's finches (Carpodacus cassinii) sing long, complex songs that incorporate many elements mimicked from other species. Although one-year-old males (males in their first breeding season) are sexually competent and do breed, they sing a simpler song (fewer syllable types) than do males two or more years old (called after-second-year males). Females do occasionally sing, but with much less stereotypy and complexity than breeding males of any age. We collected brains from free-living breeding after-second-year males (identified by their red plumage), one-year-old males (identified by their female-like brown plumage), and adult females to examine sex- and age-related differences in three song-control nuclei: HVC, Area X and RA. Nuclei volumes were reconstructed by measuring the Nissl-defined area in every second section. There was a large sex difference in all three nuclei, with female volumes 40-50% that of males. There was no difference in HVC volume between age classes of males. However, one-year-old (brown) males had significantly larger Area X volume than did the older (red) males, with red males' Area X about 75% the volume of brown males'. These data raise questions regarding the functional significance of Area X and related nuclei in relation to song development in vocal mimics.
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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 | 0.001 | 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) | 0.001 | 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".