Comparative reproductive strategies between long-tailed ducks and king eiders at Karrak Lake, Nunavut: use of energy resources during the nesting season
Bibliographic record
Abstract
Energy demands can be particularly high in arctic-nesting birds that face harsh, unpredictable conditions during the breeding season. Consequences of these demands, particularly energy-partitioning during egg laying and incubation, are fundamentally important for arctic nesters. This study investigated differences in breeding strategies between Long-tailed Duck (Clangula hyemalis) and King Eider (Somateria spectabilis) in the central Canadian arctic. The focus was on ecological variables and influences of variation in nutrient resources used during incubation and egg production. Research was done at Karrak Lake, Nunavut, where both species nest sympatrically at relatively high densities, permitting comparative research about breeding strategies. This study used stable-carbon (δC) and nitrogen (δN) isotope analysis to investigate origins and allocation of endogenous (stored) and exogenous (external) nutrients used in egg production. Remote temperature sensors were placed in nests to estimate and compare incubation rhythms and gain insight into capital and income incubating strategies of both species. Results suggest that breeding Long-tailed Ducks and King Eiders used a “mixed” breeding strategy, that is they relied on both exogenous and endogenous resources for reproduction. Close correspondence between δC and δN values of egg components and potential diet items indicated that King Eiders allocated exogenous nutrients for egg production (albumen 98.1%, yolk protein 96.8%, whole yolk 98.4%, and yolk lipids 84%). Female King Eiders relied on endogenous nutrients for incubation, as evidenced by high incubation constancy (96%). Conversely, the range of δC values in components of Long-tailed Duck eggs and δC values of diet items suggested that although some females allocated endogenous reserves for egg production, most females allocated exogenous resources for egg production (albumen 98.5%, yolk protein 78.3%, whole yolk 84.9%, and yolk lipids 38.3%). Long-tailed Duck females had an 84% incubation constancy, suggesting less reliance on endogenous nutrients for incubation than was estimated for female King Eiders. Knowledge about the relative importance of endogenous reserves and exogenous nutrients for egg production and incubation may help direct management decisions to specific winter/staging and or breeding areas used by King Eiders and Long-tailed Ducks.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.004 |
| Scholarly communication | 0.000 | 0.003 |
| Open science | 0.001 | 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".