Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore
Bibliographic record
Abstract
The cumulative effect of individual‐level foraging patterns may have important consequences for ecosystem functioning, population dynamics and conservation. Dietary specialization, whereby an individual exploits a subset of resources available to the rest of the population, can develop in response to environmental or intrinsic population factors. However, accurate assessment of individual diets may be difficult because analyses of recent food intake may misrepresent foraging variability within a heterogeneous environment. We used quantitative fatty acid signature analysis (QFASA) and a novel index of longitudinal dietary change to examine the individual foraging patterns of 64 polar bears Ursus maritimus successively sampled in Western and Southern Hudson Bay between 1994–2003. Estimated diets varied between and within age and sex classes, with adult male polar bears consuming significantly more bearded seal Erignathus barbatus than adult female or subadult bears, whose diets were dominated by ringed seal Pusa hispida . Among individual adult males, consumption of bearded seal accounted for 0–98% of the diet and bearded seal consumption was positively correlated with individual dietary specialization, as measured by proportional similarity ( PS i ) to the rest of the population. Most individual diets were consistent from year‐to‐year and were therefore not a product of short‐term heterogeneity in prey distribution. However, a novel dietary change index indicated that adult male polar bears had the most temporally variable diets with 23% of adult males switching their diet from predominantly ringed seal to predominantly bearded seal or vice versa. We conclude that QFASA is well‐suited to analyses of individual‐level foraging because it reflects an animal's diet over the preceding weeks to months. The subpopulations of bears in this study were near the southern limit of their species range and have experienced negative individual‐ and population‐level impacts related to sea ice loss and climate warming. The tightly constrained diets of some individuals, particularly adult females and subadults, may make them especially sensitive to future climate 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 | 0.000 | 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".