Sex determination of Eastern White-crowned Sparrows ( Zonotrichia leucophrys leucophrys ) using wing chord length
Bibliographic record
Abstract
Determining the sex of individuals in sexually monomorphic bird species outside of the breeding season is difficult. However, many monochromatic species exhibit sex differences in morphometrics, including wing chord length. For example, recent studies found that the Puget Sound (<em>pugetensis</em>) and Gambel’s (<em>gambelii</em>) subspecies of White-crowned Sparrow (<em>Zonotrichia leucophrys</em>) can be sexed reliably using wing chord length. However, the Eastern subspecies (<em>leucophrys</em>) has not been evaluated. We measured the wing chord length of Eastern White-crowned Sparrows migrating through the Long Point Bird Observatory and specimens from the Fatal Light Awareness Program to determine if this subspecies can be reliably sexed using wing chord length. We combined wing chord length measurements with molecular sexing to test the prediction that males have a significantly longer wing chord length than females. Unfortunately, we only captured one definitive-cycle female and were thus unable to test our prediction in definitive-cycle birds. Males in first-cycle plumage had significantly longer wing chord lengths than females in first-cycle plumage and, outside of an overlapping range (74–76 mm), this subspecies can be reliably sexed using wing chord length. Our results support the use of wing chord length as a tool for bird banders and researchers to determine the sex of Eastern White-crowned Sparrows in first-cycle plumage in the hand outside of their breeding season or in the absence of a cloacal protuberance or brood patch.
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 | 0.000 |
| 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 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".