Effects of aircraft disturbance on behaviour of harlequin ducks (Histrionicus histrionicus)
Bibliographic record
Abstract
I studied behaviour of Harlequin Ducks (Histrionicus histrionicus) at Fig River (53° 03' N, 63° 09' W) and Crooked River (54° 06', 60° 48' W) in Labrador in spring and summer of 1999 to 2002. Observations indicated that paired adults devoted modest proportions of time (30 to 40%) to foraging. This, and the lack of variation in time budgeted to feeding across time and space, indicated that Harlequin Ducks were not limited by food on their breeding habitat in Labrador. -- Most pair bonds dissolved by early June indicating nest initiation by the females. All adult females that were examined following capture and/or followed by radio signal appeared to be reproductively active. Low annual productivity on the study areas appeared to be due to predation of nests, and I concluded that Harlequin Ducks breeding in Labrador may be limited by predators. -- Noise is a significant stressor for animals, and the non-auditory effects of noise are considered whole body stress responses. In addition to overt responses, behavioural effects of noise on adult Harlequin Ducks were subtle and protracted. I interpreted this as evidence that a larger 'whole body' or physiological response was occurring. Animals challenged repeatedly develop high circulating levels of stress hormones in the bloodstream that can ultimately lower survival and inclusive fitness. -- Alert responses by adult Harlequin Ducks in central Labrador occurred to noise (75- 120 dBA) generated from low-level (30- 100m agl) military jet over-flights. Alert (startle) was generally <1% of time budgets, and increased in a dose-response manner, accelerating above a threshold of approximately 80 dBA. Protracted effects included increased inactivity, and decreased time out of water. There was evidence of residual effects of increased agonistic behaviours up to 1 h and decreased courtship up to 1.5 h following over-flights by military jets. The protracted and residual effects have the potential to negatively affect time-activity budgets of individuals. Multivariate statistical analyses demonstrated the importance of considering behaviour holistically because the inclusive modeling of covariance among behaviours was superior to traditional univariate approaches. Important effects may easily be overlooked because of bias by researchers in defining 'behavioural responses' a priori (e.g. Startle or Alert) that are easily observed because effects can be subtle and protracted well beyond the actual disturbance.
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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 | 0.000 | 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) | 0.001 | 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".