Age-related feeding site selection in urban pigeons (<i>Columba livia</i>): experimental evidence of the competition hypothesis
Bibliographic record
Abstract
Although age-specific habitat use has received much attention in recent years, the mechanisms that underlie ecological separation are not well known. This study examined the age-specific feeding site selection and its ecological mechanism in free-ranging Rock doves (Columba livia; referred to as pigeons). The distribution of age-classes at the feeding sites adjusted to a partially truncated distribution as follows: adults were consistently found more often than expected in the most rewarding feeding site, while juveniles were more often found in suboptimal sites. A removal experiment was conducted to determine whether competition accounted for the niche segregation between juvenile and adult pigeons. The reduction in intraspecific competition following removal was accompanied by an increased use of the preferred feeding site by juveniles. However, when the population recovered its initial size through immigration, juveniles were once again more frequently found in the suboptimal site. The proportion of juveniles feeding in each site was related to the total number of birds present; the higher the total number of birds, the higher the percentage of juveniles feeding in the less preferred site. These results support the idea that segregation between age-classes is due to competition by which adults displace juveniles from the richer foraging sites.
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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 | 0.000 | 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) | 0.001 | 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".