CLIMATE CHANGE, SPRING TEMPERATURES, AND TIMING OF BREEDING OF TREE SWALLOWS (TACHYCINETA BICOLOR) IN SOUTHERN ONTARIO
Bibliographic record
Abstract
Several European studies have indicated advances in breeding dates of birds in the last 30 years, which authors attributed to climate change.In North America, Dunn and Winkler (1999) reported a continent-wide advance of fi ve to nine days in breeding dates of Tree Swallows (Tachycineta bicolor) between 1959 and 1991.I present results of an intensive study of Tree Swallows breeding on and near Long Point, Ontario, at four sites monitored 1969-2001, 1977-1986, 1978-2001, and 1987-2001.Local air temperatures varied among sites, according to distance from Lake Erie, but there was no signifi cant regional trend in April and May temperatures between 1969 and 2000.Median and 10th percentile dates of clutch initiation by females that were at least two years old varied among years by up to 20 days overall and 18 days within sites, and differed by 0-14 days between sites in the same year.There were no signifi cant differences in average timing of laying among the 1970-1980, 1980-1990, and 1990-2000 periods.Nevertheless, there was a signifi cant trend towards earlier laying in 1990-2000, which was attributable to exceptionally early laying and warm May weather in 1998-2001.Across all sites, median dates of clutch initiation were strongly correlated with average daily maximum temperatures in the fi rst four, fi ve-day periods in May, but clutches at one site were initiated three days earlier than predicted by temperatures alone.I estimate that climate warming of 5C in May could result in an average advance of about seven days in the median date of laying of Tree Swallows at those sites.My results indicate that spring temperatures are strongly correlated with timing of laying, but show that spring temperatures have not increased in the Long Point region and timing of the breeding season has not advanced throughout North America.
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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".