Trade-offs in the early development of tree swallows (Tachycineta bicolor): offspring characteristics, offspring quality, and parental care
Bibliographic record
Abstract
Life-history theory predicts that because organisms have limited resources available to them, they must make decisions to prudently allocate resources in a way that maximizes fitness.Therefore, there is expected to be a trade-off between current reproductive effort and future survival and reproduction, with those individuals investing in a current breeding attempt doing so at a cost to their own survival and/or future fecundity.Altricial birds rearing young are consequently expected to be prudent in their allocation of resources between broodmaintenance and self-maintenance, and their allocation choices may be influenced by numerous offspring characteristics that potentially indicate offspring "quality" or condition.My thesis had three main goals: 1) to understand if the smallest nestling tree swallows in a nest are of inherent poor "quality", or if they are the smallest simply due to being outcompeted by their older and larger siblings; 2) to investigate whether, in an environment with parasites, it is the parents or their offspring who bear the costs associated with parasitism; and 3) to better understand the function of gape and flange colouration in nestling tree swallows.Overall, I wanted to understand how each of these nestling characteristics affect, and are affected by, parental life-history trade-offs.By pairing observational data with a cross-fostering experiment, I determined that both total egg mass and yolk mass increased with order of laying.N estlings that hatched earlier in the hatching sequence and were manipulated to be smaller within the size hierarchies in nests performed in a similar fashion as if they had retained their size advantage, but had lower immune responses, which may be because these earlier-hatched nestlings hatched from earlier-laid eggs with smaller yolks.By manipulating parasite levels in nests and then comparing nestling immune function and growth, and parental provisioning rates with control nests in a three-year study, I observed no
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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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".