Sex differences in diving at multiple temporal scales in a size‐dimorphic capital breeder
Bibliographic record
Abstract
Summary Air‐breathing marine predators can modify their diving behaviour to accommodate different patterns of prey abundance and distribution and may do so at multiple temporal scales (individual dives, bouts of dives and foraging trips). The grey seal, Halichoerus grypus, is a size‐dimorphic, capital breeding species in which sex differences in foraging ecology have previously been found at the scale of individual dives. In this study, diving behaviour of male and female adult grey seals was examined at the temporal scales of dive bouts (41 males/46 females) and foraging trips (7 males/9 females) during the 8‐month prebreeding foraging period between 1992 and 1999 to investigate whether sex differences were evident at longer temporal scales. Foraging trip duration did not differ between males and females. However, females (the smaller sex) spent significantly more time diving and less time hauled‐out on land between trips than males. This suggests that females are more selective than males when searching for prey. These differences are consistent with the effects of body‐size dimorphism on diving behaviour. Virtually all dives occurred in bouts. At this scale, males and females showed significantly different seasonal patterns of most bout characteristics, including bout duration, percentage of bout spent at depth and effort (hours spent in bouts day−1). Grey seals used four different types of bouts, differing in duration, depth, percentage bout spent at depth and the shape of individual dives within the bout. Males and females differed in the proportion of each bout type used and in the seasonal and day–night distribution of bout types. Few bout characteristics varied significantly among years, despite interannual variation in prey abundance. Where interannual differences did occur, both sexes behaved in a similar way. Different seasonal patterns in bouts of diving by males and females could not be accounted for by body‐size dimorphism or niche divergence, but were consistent with the hypothesis that females must recover condition earlier in the year than males to support the energetic costs of reproduction.
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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 | 0.000 | 0.000 |
| 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) | 0.002 | 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".