On Photoperiod and Captive Breeding of Northern Peregrines
Bibliographic record
Abstract
Vol. 6, No. 2 year.Migratory species (at least) when placed on long daylengths put on weight -develop their fat deposits (Wolfson 1959)-presumably in preparation for migration.The length of time it takes for the birds to come into breeding condition depends on a number of factors (light intensity, species, etc.).While the testes of males will develop fully in response to long days, the ovaries of females will not develop fully solely due to photoperiodic stimulation.For full ovarian development females, apparently, also require "psychic" factors-nesting material and/or a nesting site and, perhaps, a photoactivated male also (Farner 1959).Many species respond to the rather long days of a natural spring by breeding.However, before the longest day of summer is reached, their gonads have regressed and they have lost their ability to breed until the following year (see Schwab 1970: Fig. 1 ).The rather long spring days "turn on" the birds; the even longer days near June 21 appear to "turn them off."Various researchers have shown that by holding the birds at a certain daylength, they can be kept in breeding condition for many months.Male Starlings (Sturnus vulgaris).fromCalifornia held on daylengths of 10V2 or 11 hours remained in breeding condition "for at least 15 months" (Schwab 1970).With 12 hours of daylight they came into breeding condition and then passed through it in a couple of months, as in the wild.That is, the longer day apparently caused their breeding cycle to eventually end, whereas slightly shorter daylength caused the birds to remain in breeding condition for over a year (until the experiment was ended).The daylengths required for this response seem to vary with latitude (where the birds originated) and with species.Some species, when held for many months on winter (short) daylengths, have eventually started to come into breeding condition.This response has led to the suggestion that birds summate or "store up" something from daylengths.Apparently, when they have "stored up" enough, they will come into breeding condition.This is the "summation hypothesis."The period of darkness each day may be as important as the period of light.A number of experiments have shown that a long night (short day) which is broken by a period of light (even a short period of light) can affect the bird in the same way as a short night (long day).
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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) | 0.003 | 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".