Breeding biology of the Pelagic Cormorant ( <i>Urile pelagicus</i> ) at Cape Peirce, Alaska
Bibliographic record
Abstract
We studied the breeding biology of the Pelagic Cormorant (Urile pelagicus) around the Cape Peirce peninsula (58°32’N, 161°46’W) on the Bering Sea coast of Alaska, USA, in 1970 and 1973. Although our results are historical, such information is crucial to understanding the extent and nature of changes to ecosystems in the face of rapid environmental change. The breeding population in 1970 was around 700 birds. The cormorants arrived during the last 1–2 weeks in April and began breeding by the end of April. They constructed nests of beach wildrye (Leymus mollis) on sheer cliffs, preferring open ledges 3–40 m above the shore. Pairs commenced clutches from 15 May to 16 June (mode: 28 May). Mean clutch size was 3.2 eggs (mode: 3; range 1–5). The mean laying-to-fledging period was 79 days. In 1970, 1.5 young fledged per initial nest (mode: 2; range: 1–3). Survival was high during incubation, due to low predation. During the nestling period, one or two smaller chicks were lost to starvation in 93% of nests that hatched three or four chicks. Significantly more chicks were lost during the nestling period on the west-facing cliffs than on the south-facing cliffs in 1970 due to whole-brood loss that was presumably related to weather. Fall departure was gradual, with most birds gone by 25 September in 1973. Compared to a non-migratory population farther south at Mandarte Island (48.6°N), British Columbia, Canada, the migratory Cape Peirce population began laying 11 days earlier, had a laying period 15 days shorter, had lower clutch size, fledged fewer young per nest, and had higher egg survival but lower nestling survival, because brood reduction through chick starvation was negligible at Mandarte Island. From southern British Columbia to the Arctic, clutches of the Pelagic Cormorant are intrinsically limited to a range of 1–5 eggs (and rarely hatch more than four) and show no latitudinal increase in size. We conclude that extrinsic (environmental) factors strongly influence the realized mean and range in clutch size, egg survival, and chick survival throughout this species’ range.
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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".