@meltedcheese Found it, 2017 item in Scientific American by Amanda Montañez
https://www.scientificamerican.com/article/beyond-xx-and-xy-the-extraordinary-complexity-of-sex-determination/

@peachfront Seems to be indeed the white-necked jacobin, based on the references in the captions. e.g. https://royalsocietypublishing.org/rspb/article/289/1982/20220332/79500/Intersexual-social-dominance-mimicry-drives-female

There is No (scientific) Consensus on Biological Sex. The title and summary of a new paper on how scientists define sex, the lack of unanimity on the topic, and how some of the existing definitions just don't work for all organisms.

Link: https://onlinelibrary.wiley.com/doi/10.1111/ele.70350

#Biology #Sexuality