Helmeted Woodpeckers roost in decay-formed cavities in large living trees: A clue to an old-growth forest association
Bibliographic record
Abstract
Abstract Woodpeckers (Picidae) are broadly associated with forests but vary in sensitivity to habitat alteration, with some species restricted to mature and old-growth forests, usually because of their foraging or nesting requirements. Roosting sites have rarely been considered a critical resource for woodpecker conservation because nearly all woodpecker species roost year-round in excavated cavities similar to their nest sites. A possible exception is the globally vulnerable Helmeted Woodpecker (Celeus galeatus) of the Atlantic Forest of South America. To determine whether roosting ecology may explain their association with mature forest, we radio-tracked 12 Helmeted Woodpeckers in old-growth and selectively logged forests in Argentina, monitored roost cavities, and provided 9 roost boxes. Unlike other woodpeckers, Helmeted Woodpeckers roosted year-round in decay-formed cavities (n = 21), with perching space above the entrance, in the living trunks of large trees. Adults usually roosted alone, but after nesting (in excavated cavities), each adult roosted with one juvenile in a shared, decay-formed cavity for up to 67 days, implying that cavities need enough space for 2 birds. We did not observe use of roost boxes. Helmeted Woodpeckers travelled up to 1,482 m between nests and roosts, reused roost cavities over multiple years (sometimes changing ownership), and interacted aggressively with other cavity-nesting birds at roost cavities, indicating that suitable cavities are a scarce resource. Because logging is likely to have a strong negative impact on the availability of this resource, we urge managers in the Atlantic Forest region to retain large living trees with decay-formed cavities and to allow more selectively logged areas to become old growth.
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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) | 0.003 | 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".