DEVELOPMENT OF FORAGING SKILLS AND THE TRANSITION TO INDEPENDENCE IN JUVENILE SAVANNAH SPARROWS
Bibliographic record
Abstract
We investigated the timing and pattern of the development of foraging skills in juvenile Savannah Sparrows (Passerculus sandwichensis). Juveniles of known age, parentage, and in some cases sex were mist netted and tested in an aviary on Kent Island, an isolated island in the Bay of Fundy, Canada. Captive birds were exposed to three standardized and ecologically relevant foraging tasks: locating spittle bugs (Homoptera: Cercopidae) in spittle masses on goldenrod (Solidago rugosa) plants, small caterpillars under spruce (Picea glauca) bud scales, and beetle larvae under leaves. The feeding trials involved 33 juveniles aged 17–42 days, four independent juveniles whose precise ages were not known, and five adults for comparison. The performance of juvenile sparrows on all three tasks showed rapid improvement between 22 and 24 days of age. Thereafter, foraging proficiency (number of foraging attempts, number of prey obtained, foraging efficiency) did not improve significantly with age among juveniles; in fact, older juveniles performed as well as adults. Juvenile males obtained more prey items than juvenile females in aviary trials. Foraging proficiency in captivity was not a good predictor of survival to the following year, and it appeared not to be influenced by brood membership or parental age. The age at which foraging performance improved in captivity coincided with the age at which parents cease attending their fledglings in the field, suggesting that the duration of postfledging parental care may be determined by the speed at which juveniles can develop foraging skills. Desarrollo de Destreza para Forrajear y Transición a la Independencia en Juveniles de Passerculus sandwichensis Resumen. Investigamos el tiempo y el patrón de desarrollo de destreza para forrajear en juveniles de Passerculus sandwichensis. Se capturaron y se evaluaron juveniles de edad, origen, y (en algunos casos) sexo conocidos en una pajarera en Kent Island, Bahía de Fundy, Canadá. Las aves capturadas se expusieron a tres tareas de forrajeo estandarizadas y ecológicamente relevantes: localizar insectos (Homoptera: Cercopidae) en su espuma en hierbas (Solidago), orugas pequeñas en las ramitas de Picea glauca, y larvas de escarabajo debajo de hojas. Utilizamos 33 juveniles de 17–42 días de edad, 4 juveniles independientes de edades desconocidas y 5 adultos para comparar. El desempeño de los juveniles en las tres tareas mostró una mejoría rápida entre 22 y 24 días de edad. A partir de entonces, la competencia al forrajear (número de intentos de forrajeo, número de presas obtenidas, eficiencia de forrajeo) no mejoró significativamente con la edad entre los juveniles; de hecho, los juveniles mayores se desempeñaron tan bien como los adultos. Los machos juveniles consiguieron más presas que las hembras en las pruebas. La competencia al forrajear en cautiverio predijo la sobrevivencia hasta el siguiente año adecuadamente, y pareció no ser influenciada por la nidada a que se pertenecía o por la edad de los padres. La edad en que la competencia al forrajear mejoró en cautiverio coincidió estrechamente con la edad en que los padres dejan de cuidar a los volantones en el campo, lo cual sugiere que la duración del cuidado de los padres después de que los polluelos salen del nido puede ser determinada por la rapidez con que los juveniles puedan desarrollar destreza para forrajear.
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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 | 0.001 |
| 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".