Crepuscular foraging by a pursuit-diving seabird: tactics of common murres in response to the diel vertical migration of capelin
Bibliographic record
Abstract
The spatial and temporal distribution of prey directly influences the foraging and feeding behaviour of predators. To investigate predator-prey interactions through the diel cycle, we examined continuous records of diving activity by a pursuit-diving seabird, the common murre Uria aalge, in conjunction with fine-scale data on the vertical distribution of their main prey, capelin Mallotus villosus, off the northeast Newfoundland coast, Canada. Diurnal patterns in the diving activities of murres closely reflected changes in the vertical distribution and movements of capelin. During daylight hours, 43% of murre dives were deep ( 50 m), bringing murres into sub-0C water in the Cold Intermediate Layer (CIL; ~40 to 240 m), when 82% of capelin biomass was located within or below the CIL. At night, murres concentrated diving activity at shallower depths (94% of dives were < 50 m) when 86% of capelin biomass was in the upper water column. Capelin migrated through the water column during twilight periods, moving up at dusk and down at dawn. In response, murres' diving frequency increased and diving depths were graduated, becoming shallower through dusk and deeper through dawn. Crepuscular habits indicate that capelin are more accessible during twilight periods. In summary, though murres are constrained by commuting costs, they show exceptional behavioural flexibility in their efforts to access capelin throughout their diel vertical migration (DVM). The various trade-offs involved in such predator-prey interactions are discussed, as are the ecological consequences of the DVM pattern across trophic levels.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.002 |
| 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 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".