Reproduction, predation, and population decline in collared lemmings
Bibliographic record
Abstract
One of ecology’s major challenges is explaining how animal populations fluctuate in time. We tested whether reduced reproduction was a contributing cause of a cyclic decline in a collared lemming ( Dicrostonyx groenlandicus (Traill, 1983)) population in northern Canada. The decline began in autumn and winter (1996/97) and continued the following summer (1997). We concluded previously that predation was a primary cause of the summer lemming decline, and limited summer population density. Here, we recorded changes in lemming reproductive condition and estimated winter predation on lemmings from predators’ functional and numerical responses. Most lemming reproduction stopped late in peak summer 1996 but recovered in decline summer 1997. Estimated winter predation during the decline was similar to summer radio-telemetry mortality estimates. We conclude (1) in autumn and winter, a decreased reproductive rate and increased predation by Arctic foxes and avian predators before snowfall may have contributed to winter decline; (2) in summer 1997 reproduction recovered; hence, a low summer reproductive rate was not a factor in the continuing decline. Winter declines from high collared lemming density may be driven by absence of winter reproduction, along with mortality caused by predation and harsh winter weather.
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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".