Differences in molt timing, duration, and intensity between sexes in a Rufous-collared Sparrow population from central Chile

Carlos E. Valeris-Chacín, Tomás F. Zamorano-Escalona, Katherine R. Chávez-Vásquez, Guyleine Rios-Robles, Mariana Klesse, Pablo A. Cornejo-Escobar, Marcela Osorio, and Rodrigo A. Vásquez


Description:
This dataset contains information used to evaluate differences in molt parameters between male and female Rufous-collared Sparrows (Zonotrichia capensis) from central Chile. Molt is a key life history stage in birds, involving the replacement of flight feathers that affects flight performance and thermoregulation.

The data include scores of flight feathers for each individual, used to estimate molt timing, duration, and intensity following the Underhill–Zucchini models I and II. Molt intensity was assessed as the sum of actively molting flight feathers. Feather growth rate was estimated using a photographic ptilochronology method (photo-ptilochronology) applied to field photographs of feathers.

The dataset allows the comparison of molt variables between sexes and can be used to explore relationships among molt dynamics, reproductive investment, and life-history strategies. In this study, females began molt later and had a shorter molt duration than males, replacing more feathers simultaneously, whereas feather growth rate did not differ statistically between sexes.

File contents:

molt_data.csv — individual-level molt scores, sex, date.

feather_growth_rate_data.csv — feather growth rate estimates from photo-ptilochronology, sex and date.

molt_intensity — individual-level number of flight feather molting between categories 2 and 4, and sex.

metadata.csv — variable definitions and measurement units.

Geographic coverage: Quebrada de La Plata Natural Sanctuary, Maipú, Central Chile. Coordinates: 33°29'49" S/ 70°54'39" W
Temporal coverage: [September 2018- January 2020]
Methods: Mist-netting and birdbanding, molt scoring (Ginn 1975, Ginn and Melville 1983, and Newton 2009, Underhill–Zucchini models I & II, and photo-ptilochronology
License: [CC BY 4.0]
Citation: Please cite the associated article once published in Journal of Field Ornithology.