Colonization-extinction dynamics of opossums on small islands in Panama
Bibliographic record
Abstract
We studied the distributions and colonization-extinction dynamics of five species of opossums (Didelphis marsupialis, Marmosa robinsoni, Philander opossum, Caluromys derbianus, and Metachirus nudicaudatus) on 12 small islands in Gatun Lake in central Panama. Opossums were censused by monthly livetrapping from 1991 (eight islands) or 1993 (four islands) through 1995. We recorded 75 colonizations over the course of the study. Didelphis marsupialis was the most frequent colonizer and accounted for 56% of all colonizations recorded. However, only four D. marsupialis populations that reproduced successfully resulted from these colonizations, and most populations went extinct. Marmosa robinsoni and P. opossum also frequently colonized these islands but rarely established successful populations. Multiple linear regression was used to relate the mean numbers of colonizations and population establishments per year and mean and standardized persistence times of all five species of opossums to island size and isolation. These four dependent variables were not related to island area or isolation distance. This system, characterized by frequent colonizations and extinctions, fit the mainland-island metapopulation model, and nearby mainland areas that maintained persistent populations of all five species provided colonists to the small islands.
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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 | 0.000 | 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) | 0.003 | 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".