Behavioural and physiological responses to food availability and predation risk
Bibliographic record
Abstract
Several empirical studies have demonstrated the existence of intraspecific variation in age and size at reproductive maturity for organisms experiencing different food environments and predation risk. For some species, these changes have been shown to arise primarily through changes in foraging activity. Theoretically, changes in age and size at maturity can arise through either behavioural or physiological responses. Here we analyse two models. The first is a conventional life-history model with no explicit recognition of the physiology of energy utilization by the organism – growth (i.e. weight gain) is simply the difference between assimilation and respiration, and there are no physiological restrictions on the timing of maturation. The changes in age and size at maturity in response to food availability and predation risk predicted by this model are consistent with published experimental data for one particular species, the midge Chironomus tentans. Numerical calculations with parameters appropriate to this species suggest that the optimal response is purely behavioural. The second model is a general, dynamic energy budget model that takes account of the energetic costs associated with development to reproductive maturity. With that model, we prove that the optimum partitioning of energy between growth and development is independent of predation risk and food availability, thereby demonstrating the generality of the previous finding with the life-history model. On the basis of the combined insight from the two models, we propose that fixed allocation to growth and development, despite variation in food availability and predation risk, is optimal for a broad class of life histories. Consequently, the absence of an allocation response to experimental manipulation of food or predators should not necessarily be taken as evidence for physiological or other constraints on life-history adaptation.
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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 | 0.001 | 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 | 0.001 | 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) | 0.000 | 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".