Morphometric measurements permit accurate sexing of three species of Mesoamerican ground-sparrow (Genus: <i>Melozone</i> )
Bibliographic record
Abstract
The natural history of many tropical bird species is poorly described, preventing more detailed studies of ecology, behavior, and evolution. For most sexually monochromatic tropical bird species, we lack field methodologies to categorize the sex of adults. In this study, we describe sex-based morphological differences of three monochromatic species in the genus Melozone White-eared Ground-Sparrow, M. leucotis; Prevost's Ground-Sparrow, M. biarcuata; and Rusty-crowned Ground-Sparrow, M. kieneri. We collected six standard morphological measurements (tarsus length, tail length, wing chord length, culmen length, beak width, and beak depth) from live birds and museum specimens. We collected data from all recognized subspecies of the three Mesoamerican Melozone species. Morphological measurements capably distinguished males from females in all three species. In all cases, three or fewer morphological measurements were required to identify sex with accuracy levels that ranged from 75–100%, well beyond the 50% expected by chance. Comparisons involving all six measurements yielded accuracies that ranged from 58–93%. Our results provide the first field-based method for estimating the sex of individuals in this poorly studied genus of tropical birds. We recommend our findings be used to distinguish males from females in banding stations where Melozone ground-sparrow species occur.
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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 | 0.001 | 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 | 0.001 | 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 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".