We are glad to present this new section, where for each new issue of the JFO, one of the journal’s co-Editors-in-Chief will highlight their favorite paper.
This edition is courtesy of Dr. Mark E. Hauber.
The selected paper was:
“Variation of iris color in Spotted Towhees (Pipilo maculatus) in urban areas in the lower-mainland region of British Columbia, Canada” by Triana I. Hohn, Grace Karimpanal and Elizabeth A. Gow (2025, Issue 3, JFO).
Mark says:
“The eye’s iris appearance is one of the most “in-your-face” variable traits in birds, yet it is perhaps the least well understood amongst all the different avian colors. Age and sex are often strong predictors of iris hue, for example. Importantly, recently, both broadly comparative and lineage-specific (owls) research has explored why iris colors are so diverse.
Fig. 1. Visual summary of the methodology used to extract RGB values from digital photographs of Spotted Towhees (Pipilo maculatus) taken under field conditions at the study’s four study sites in the lower mainland of British Columbia, Canada during the 2022–2023 breeding and 2022–2024 non-breeding seasons.
Fig. 2. Examples of Spotted Towhees (Pipilo maculatus) that were consistently aged correctly (“consistent”) and incorrectly (“inconsistent”) according to iris color from each age and sex class captured during the 2022–2023 breeding and 2022–2024 non-breeding seasons in the lower mainland region of British Columbia, Canada. ASY = After Second Year. SY = Second Year. AHY = After Hatch Year. HY = Hatch Year.
Along these lines of investigations comes a new study published in the Sept. 2025 issue of Journal of Field Ornithology, examining the iris-color variation using digital photography in urban Spotted Towhees. Here the researchers found that lightness and redness of the iris was dependent on age, sex, and year of investigation, but only during the breeding season. These results indicate a role for reproductive physiology in shaping the plasticity and function of towhee iris coloration variation.”
The results of this study were recently published in the Journal of Field Ornithology:
Hohn, T. I., G. Karimpanal, and E. A. Gow. 2025. Variation of iris color in Spotted Towhees (Pipilo maculatus) in urban areas in the lower-mainland region of British Columbia, Canada. Journal of Field Ornithology 96(3):2. https://doi.org/10.5751/JFO-00666-960302.
Header photo: Spotted Towhee (Pipilo maculatus) by raclro | Getty Images.