COLOR DIFFERENCES AMONG CLOSELY RELATED SPECIES OF RED-BREASTED MEADOWLARKS (STURNELLA)
Bibliographic record
Abstract
Abstract. Interspecific differences in sexually selected traits may be important for maintaining reproductive isolation among closely related species living in sympatry. We present the first study of plumage color differences among males of partially sympatric species of South American red-breasted meadowlarks—the White-browed Blackbird (Sturnella superciliaris), the Pampas Meadowlark (S. defilippii), and the Long-tailed Meadowlark (S. loyca)—using reflectance spectrophotometry and the avian visual model of Vorobyev and Osorio (1998). Reflectance values of sexually dichromatic red plumage patches were measured on study skins. Total reflectance, reflectance in the short wavelength part of the spectrum, and several measures of spectral shape were extracted directly from the spectra. Our analyses revealed that S. loyca and S. defilippii were brighter and had higher reflectance in the short wavelength part of the spectrum than S. superciliaris. Minimum reflectance was located at higher wavelengths in breeding than in nonbreeding plumage. Interspecific distances in avian visual space obtained from the Vorobyev and Osorio (1998) model were considerably higher than the threshold value for color discrimination, indicating that the differences found are also detectable by birds. Taken together, these results show that the red plumage patches of these three species present significant color differences throughout the year, not only in the visible but also in the UV part of the spectrum.
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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 | 0.001 |
| 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 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".