Sexing Monochromatic Birds in the Field: Cryptic Sexual Size Dimorphism in Buff-breasted Wrens (thryothorus Leucotis)
Bibliographic record
Abstract
Resumen.-Determinación del sexo de aves monocromáticas en el campo: dimorfismo sexual críptico en Thryothorus leucotis.-Trabajar en el Neotrópico trae consigo desafíos especiales para los interesados en determinar el sexo de las aves residentes, pues muchas especies son monocromáticas y aparentemente monomórficas, y los individuos de ambos sexos pueden cantar y defender territorios.En este estudio, comprobamos que es posible determinar confiablemente el sexo de individuos de la especie Thryothorus leucotis utilizando medidas sencillas del tamaño corporal.Comparamos el tamaño de machos y hembras conocidos por medio de pruebas t pareadas y análisis de regresión logística.A nivel de la población, los sexos se superpusieron en todas las mediciones, aunque en promedio los machos fueron más grandes que las hembras.Al considerar parejas individuales, los machos fueron significativamente más grandes y más pesados que las hembras.El mejor modelo logístico indicó que la medida de la cuerda alar fue suficiente para discriminar entre machos y hembras, clasificando correctamente al 95.5% de los individuos.Tres individuos (dos machos y una hembra) fueron clasificados incorrectamente por el análisis de regresión, pero pudimos determinar su sexo ya que los machos fueron más grandes y la hembra más pequeña que sus respectivas parejas en todas las mediciones.Estos resultados indican que T. leucotis, una especie monocromática, presenta dimorfismo sexual críptico en tamaño.Además, nuestros resultados demuestran que es posible determinar el sexo de los individuos con base en mediciones sencillas.Es necesario realizar más estudios en otras especies monocromáticas y presumiblemente monomórficas para determinar la utilidad general de este método.Abstract.-Working in the Neotropics poses special challenges for those interested in sexing resident bird species.Many species are monochromatic and apparently monomorphic, and both sexes may sing and defend territories.We tested whether monochromatic Buff-breasted Wrens (Thryothorus leucotis) could be reliably sexed using simple body size measurements.We compared the size of known males and females using paired t-tests and logistic regression analysis (LRA).At the level of the population, the sexes overlapped in all mensural characteristics; however, on average males were larger than females.When considering individual pairs, males were significantly larger and heavier than their mates.The best model from LRA indicated that measurement of wing chord alone was sufficient to discriminate between males and females, with 95.5% of individuals correctly classified.Three individuals were incorrectly classified by LRA (two males and one female), but could be sexed by comparing them with their mates, as the males were larger ______________ 1
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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 | 0.001 |
| 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 | 0.001 |
| 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 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".