Diet overlap of overwintering migratory birds on the northern coast of the Yucatan Peninsula
Bibliographic record
Abstract
Previous studies of overwintering migratory birds in neotropical environments have found that species co-occur in the same habitats despite high diet overlap. Hence, discovering subtle diet differences within habitats can help explain patterns in bird species diversity. The Yucatan Peninsula in Mexico is an important region for overwintering migratory birds, but little is known about how habitat differences in food resources contribute to bird diversity. To address the knowledge gap, we compared the degree of overlap in the diet of all terrestrial migratory birds within and between mangrove and tropical dry forests on the Yucatan Peninsula’s northern coast. We collected data on the consumption of food items through direct observation of birds feeding on four transects in each habitat every week (12 weeks) during the non-breeding season (i.e., overwinter, December-February). We recorded 19 species, 15 species in mangrove and 15 species in forest, with 11 of those found in both habitats. In both habitats, diet overlap was high. However, species present only in the tropical dry forest had less overlap than species occurring in both habitats, indicating that diet specialization might restrict the range of habitats that a species can occupy. On the other hand, species present only in the mangrove had similar diet overlap to species present in both habitats. The diet variation that did exist was greater within than between habitats possibly due to intraspecific diet differences among different geographic locations. Although small, within-habitat diet differences might be key to allowing species to coexist locally in the Yucatan, thus supporting studies demonstrating a similar mechanism in other neotropical regions. More generally, the information we provide on bird diet can be used to discover whether threats like anthropogenic development precipitate species loss via altering the resource base upon which birds rely.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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 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".