CENSUS OF WEDGE-TAILED SHEARWATERS PUFFINUS PACIFICUS AND AUDUBON'S SHEARWATERS P. LHERMINIERI ON COUSIN ISLAND, SEYCHELLES USING CALL-PLAYBACK
Bibliographic record
Abstract
SUMMARY BURGER, A.E. & LAWRENCE, A.D. 2001. Census of Wedge-tailed Shearwaters Puffinus pacificus and Audubon’s Shearwaters P. lherminieri on Cousin Island, Seychelles using call-playback. Marine Ornithology 29: 57–64. We counted shearwaters on Cousin Island, Seychelles, and tested the call-playback method for determining nest occupancy. Wedge-tailed Shearwaters Puffinus pacificus nest synchronously and were counted during early incubation in October 1999. Audubon’s Shearwaters P. lherminieri nest year-round and were counted in February 2000. We made five refinements to the call-playback method that are applicable to other cavity-nesting seabirds. First, to minimise errors associated with the method, we applied call-playback only where cavity occupancy could not be determined by looking or feeling into the nest cavity (i.e., in 17% of Wedge-tailed Shearwater cavities, but 76% of the smaller Audubon’s Shearwater cavities). Second, we combined daytime visits to the census plots, which facilitated location of cavities, reduced disturbance to birds and minimised damage to fragile burrows, with night visits to determine occupancy. Responses to call-playbacks were significantly higher at night than by day. Third, we timed the bird’s responses to derive the optimal duration of a playback test (120 s in Wedge-tailed and 80 s in Audubon’s Shearwaters). Fourth, we used the proportions responding at night for both occupied cavities (R o ) and cavities with unknown contents (R u ) to formulate a response coefficient (R u /R o ) used to estimate occupancy in cavities with unknown contents. For Wedge-tailed, R o = 0.774, R u = 0.170 and R u /R o = 0.220, and for Audubon’s, R o = 0.714, R u = 0.164 and R u /R o = 0.229 (i.e., 22.0% of Wedge-tailed and 22.9% of Audubon’s Shearwater cavities with contents unknown were likely to be occupied). Fifth, we reported the density of several categories of nest cavity, including cavities occupied by birds, those with failed eggs or chicks, and empty potential cavities. This allows a wider range of monitoring options and comparisons with other studies. The total number of cavities occupied by Wedge-tailed and Audubon’s Shearwaters on Cousin was 13 066 (95% confidence limits 9259–16 873) and 5100 (95% CL 3976–6625), respectively. We lack an accurate method to estimate the year-round breeding population of Audubon’s Shearwater. The Wedge-tailed Shearwater population was similar to a 1996/97 estimate, but considerably less than the 1973/74 estimate of 30 000–35 000 pairs, which might have been an overestimate. There have been no previous estimates of the Audubon’s Shearwater population on Cousin Island. Continued monitoring of the Cousin Island shearwaters is recommended.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".