Individual quality and double-brooding in a highly synchronous songbird population
Bibliographic record
Abstract
Multiple brooding, the production of more than one set of offspring per breeding season, is a life-history trait that potentially doubles or triples fecundity, but the factors responsible for variation in the occurrence of multiple brooding within species remain poorly understood. We investigated the potential causes and consequences of double-brooding in the highly synchronously breeding European Starling (Sturnus vulgaris), for which we predicted that clutch initiation date would have little effect on double-brooding propensity compared with individual quality. Double-brooding effectively doubled annual fecundity in European Starlings (based on the annual number of chicks fledged), but on average only 38% of individual females had a second brood. Furthermore, 39% of females that initiated a second clutch experienced total failure of their second brood, and thus accrued no advantage in fecundity from their decision to double-brood. As we predicted, variation in the propensity for, and success of, double-brooding was independent of laying date, but also of other putative measures of individual quality (clutch size, egg mass, relative female age, and nestling provisioning rate). However, we found no evidence of a cost of double-brooding; females that double-brooded had significantly higher return rates and similar breeding productivity in the year after double-brooding compared with single-brooding females. Thus, a small proportion (~20%) of ‘high-quality' female European Starlings effectively double their potential breeding productivity through double-brooding without apparently paying a cost or experiencing any simple tradeoffs.
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 | 0.000 | 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 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".