Species limits in the Rusty-breasted Antpitta ( <i>Grallaricula ferrugineipectus</i> ) complex
Bibliographic record
Abstract
The Rusty-breasted Antpitta (Grallaricula ferrugineipectus) is widely distributed within the tropical Andes of South America. We analyzed 73 study specimens, 25 vouchered tissue samples, and 123 audio recordings to assess geographic variation in genetics, vocalizations, and morphology and evaluate species limits. We found that Grallaricula ferrugineipectus as currently defined is polyphyletic because populations from Colombia and Venezuela form a clade closely related to Andean populations of G. nana, whereas populations from Peru and Bolivia are recovered as sister to G. lineifrons. Birds in Colombia and Venezuela (the northern group) last shared a common ancestor with birds from Peru and Bolivia (the southern group) more than 10 million years ago. Northern and southern groups additionally differ in song, suggesting they may have evolved substantial premating reproductive isolation. Discriminant function analysis reliably distinguished songs from northern and southern groups in multivariate acoustic space, but univariate analyses found non-overlapping acoustic variation between northern and southern groups in only one trait: mean note maximum frequency (and other correlated measures of song pitch). This finding suggests that the ‘three-trait' threshold for using vocalizations to inform species limits, which was developed for another suboscine group, the antbirds (Thamnophilidae), may be conservative when applied to antpittas (Grallariidae). In addition, we document apparent clinal variation in song pace within the southern group, a rare example of a suboscine with geographic clinal variation in a vocal trait. Finally, we show that northern and southern groups differ markedly in morphology. In summary, northern and southern groups of Rusty-breasted Antpittas are divergent in genetics, vocalizations, and morphology, demonstrating that these taxa are best classified as 2 monophyletic, biological species with allopatric distributions.
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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 | 0.000 |
| 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".