Disentangling bidirectional relationships between glucocorticoids and behavior: Experimentally elevated corticosterone levels correlate with rapid, sex-specific changes in food-acquisition behaviors of food-limited seabird chicks
Bibliographic record
Abstract
ABSTRACT Bidirectional relationships between hormones and behaviors are hypothesized: i.e. energetic consequences of behaviors may alter glucocorticoid levels, and elevated glucocorticoids may alter behavioral responses to stimuli in context-appropriate ways. We tested these relationships between the avian glucocorticoid corticosterone and behaviors related to food-acquisition in free-living seabird chicks (Black-legged kittiwakes, Rissa tridactyla ) with robust HPA-axis activity. First, we tested the hypothesis that behavior affects HPA axis activity by quantifying chick behavior for 60 min, then taking a blood sample at baseline and 15-min post-restraint. Only feeding predicted subsequent corticosterone levels (fewer feeds = higher restraint-induced corticosterone). However, the hypothesis that increased corticosterone secretion alters behavior was supported: post-restraint corticosterone levels were positively correlated with increases in begging and aggression in the subsequent hour, primarily in males. In a second experiment, we isolated the role of corticosterone from other components of the stress response by administering exogenous topical corticosterone, which confirmed a positive relationship between subsequent corticosterone levels and changes in aggression, but not begging or feeding. Corticosterone:behavior relationships depended on nutritional context - they were eliminated in nests with experimental food supplementation. Finally, higher levels of corticosterone in response to restraint were associated with more rapid elimination of siblings, presumably increasing chick direct fitness by eliminating competition. We conclude that the magnitude of the endogenous corticosterone response to challenges is a) negatively correlated with recent feeding rates, b) subsequently associated with rapid, sex- and context-specific changes in chick behaviors, at least some of which are likely causally- driven by elevated corticosterone, and c) associated with fitness-relevant consequences.
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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 | 0.001 |
| 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".