Sex differences in parental roles and diving behaviour of thick-billed murres, URIA LOMVIA, and Razorbills, Alca Torda, at the Gannet Islands, Labrador
Bibliographic record
Abstract
There is no evolutionary, ecological or behavioural explanation for the partitioning of parental roles between the sexes in the Alcini, which includes murres (Uria), the razorbill, (Alca torda), great auk (Penguinus impennis) and dovekie (Alle alle); and why the male is the selected sex to accompany the chick to sea. I investigated parental roles and diving behaviour of two sympatric alcids, thick-billed murres, Uria lomvia, and razorbills, at the Gannet Islands, Labrador to determine whether sex-specific differences in energy expenditure at the time of departure explain male-only care at sea. Externally attached time-depth recorders (TDRs) negatively affected parental behaviour in male and female thick-billed murres. Partners of TDR-equipped birds compensated for the reduced parental effort in brooding and chick provisioning of their mates, with no differential responses between sexes. There was a temporal segregation of water depths, dive profiles, and food resources between the sexes in both species; these differences being stronger in thick-billed murres than in razorbills. Most murre females' self-feeding diving coincided with the vertical migration of crustaceans to surface waters; while male's self-feeding foraging occurred when prey were in deeper sections of the water column. Chick-provisioning diving was deeper than self-feeding irrespective of the sex or the time of day, suggesting equal parental effort allocation of the sexes underwater. Nevertheless, males had longer foraging trips than females probably due to the time spend flying to farther locations than females. Higher self-feeding rates and closer feeding locations may explain female's higher delivery rates at the breeding site. The longer time males spent brooding the chicks may serve to ensure parent-offspring vocal recognition at departure. Larger bill dimensions and higher levels of aggressive behaviour may confer males a better ability to protect the chick. In conclusion, differences in energy expenditure between the sexes did not seem to explain the male's parental role at sea. Instead, I proposed that the patterns of parental roles found between sexes was the result of a chain of events favouring male involvement in chick brooding and care at sea. A higher level of aggressiveness of the parent that escorts the chick to sea may have been selected for to ensure offspring survival, and as a result, parental roles developed at the breeding site to ensure male-only care at sea.
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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) | 0.001 | 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".