Phenotypic plasticity in the timing of reproduction in Andean bears
Bibliographic record
Abstract
Abstract Many factors influence whether mammals reproduce seasonally or continuously but disentangling them can be challenging in free‐living species that are hard to observe. We described the seasonality of reproduction in Andean bears ( Tremarctos ornatus ) in NW Peru (6°26′S, 79°33′W) to test for phenotypic plasticity in response to extrinsic cues. To do so, we compared the mating behavior and birthdates of free‐living bears to the birthdates of captive bears housed over a broad range of latitudes. Free‐living bears were observed on 302 occasions over 6 years (967 field‐days), and mating behaviors recorded 61 times from late Dec to Jan. The mean birthdate of 12 wild‐born litters was 17 August (range = 23 Jun – 15 Oct), 57 ± 10 ( SD ) days after the winter solstice. Birthdates for 367 captive litters varied widely by comparison (range = 1 Jan – 31 Dec; mean = 14 ± 49 days after the winter solstice). However, captive bears in the tropics had fewer births in autumn and winter (71.4% of births) than captive bears at higher latitudes (96.8% of births; P < 0.001). Differences in seasonal reproduction among captive bears at high and low latitudes and captive and a free‐living at tropical latitudes suggest that Andean bears display phenotypic plasticity in reproductive timing but influenced by photoperiod at high latitudes. Because photoperiodic effects were less evident at tropic latitudes, we suggest that seasonality in the timing of reproduction in the free‐living bears we observed was influenced by seasonal variation in food abundance. The observed effect of photoperiod on reproduction in captive Andean bears at high latitudes may also imply that free‐living bears at the southern edge of the range may be constrained in their ability to adjust reproductive timing to resource availability as environments change.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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) | 0.000 | 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".