Limitations
We only collected skin biopsies from the chest to limit the number of
biopsies collected per individual during the capture-and-release.
However, comparing chest skin gene expression to gene expression in a
non-sexual skin area would allow us to assess (1) whether higher male
expression associated with blood flow and vascularization is unique to
chest skin biopsies and (2) whether both male and female chests are
hotspots for expression of androgen and estrogen related genes. While we
were able to identify interesting sex differences, we were not able to
assess gene expression differences between male status categories
because anesthetizing a leader male to collect a biopsy sample would put
them at risk of losing their status. Lastly, we restricted our male
chest photo dataset to only photos taken in March and April to match our
more limited female chest photo dataset. This facilitated a more direct
comparison between the sexes, but may have reduced our ability to
identify more within-individual variation, particularly in males.