The complexity of cormorants: stable isotopes reveal multiple prey sources and feeding site switching
Bibliographic record
Abstract
Conflict between cormorants (Phalacrocorax spp.) and humans over fisheries is currently one of the most widespread wildlife management issues in the world. Cormorant impact assessments typically assume a single source of prey near the breeding colony. However, cormorants can fly long distances (>20 km), resulting in fish removal from multiple areas. Knowledge of the source of cormorant prey is critical for fisheries impact assessments. Carbon and nitrogen stable isotopes values from fish in double-crested cormorant (Phalacrocorax auritus) regurgitations revealed several prey sources for breeding birds in north-central Saskatchewan, Canada. Cormorants also switched feeding locations on a daily and seasonal basis. Foraging patterns inferred by stable isotope analysis closely paralleled observations of relative cormorant densities on different lakes. Up to 80% of prey came from areas well removed from the breeding colony lake (≤30 km). Cormorant foraging ecology can be complex and may be driven by factors independent of breeding colony site selection. The approach of estimating biomass removal from breeding colony lakes as the guideline for management decisions may be invalid in many locations.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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".