Does fresh vegetation protect avian nests from ectoparasites? An experiment with tree swallows
Bibliographic record
Abstract
Some species of birds incorporate fresh green vegetation into their nests. The adaptive significance of this behaviour, however, is unclear. The "nest protection hypothesis" suggests that volatile chemicals contained in green plants reduce populations of nest-dwelling ectoparasites. I tested this hypothesis with tree swallows, Tachycineta bicolor (Vieillot, 1808), a species that has large infestations of ectoparasites in its nests. I experimentally added green leaves of yarrow (Achillea millefolium L.) to nests and compared these nests to control nests. My results showed that nests with yarrow had significantly higher levels of infestation by fleas, and yarrow had no effect on the number of blow flies detected. There was no effect of yarrow on condition of parents, size of offspring, or the probability of nests fledging at least one young. I did, however, find that second-year (SY) females with yarrow added to their nests hatched significantly more eggs than control SY females. In addition, pairs with yarrow added to their nest were significantly less likely to suffer hatching failure and (or) brood reduction. These beneficial effects of yarrow cannot be explained by reductions in numbers of fleas or blow flies, and I suggest that these results may be due to reductions in numbers of other types of parasites not quantified in my study, such as flying insects or the diseases that they may vector. I discuss my findings for swallows in the context of results from previous studies of other species that habitually use green plant material such as yarrow in their nests.
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) | 0.000 | 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".