Demographic Responses to Food and Space Competition by Juvenile Steelhead Trout
Bibliographic record
Abstract
I conducted two experiments in artificial stream channels, manipulating density of competitors, food abundance, and the possibility of emigration, to test whether density-dependence can operate through these factors in populations of a stream-dwelling salmonid fish, juvenile steelhead trout (Oncorhynchus mykiss). In the absence of emigration, increasing levels of per capita food competition increased mortality, decreased growth, and increased the variance in size distributions of surviving individuals. Smaller fish were more likely to occupy less profitable areas of the stream channel than larger individuals and did so with increasing frequency as food abundance decreased and stocking density increased. When I allowed fish to emigrate from the stream channels, food and stocking density again influenced mortality, growth, and size distributions of survivors. Emigration was more likely at increasing levels of per capita competition; emigrants were smaller and in poorer condition than nonemigrants. The ability to emigrate from a population appears to normalize final size distributions and increase mean fish size within the stream channels. Thus, although both food and space are important factors shaping the demography of stream salmonid populations, neither appears to limit salmonid abundance exclusively.
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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 | 0.000 | 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 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".