Rhea culture is very basic, as opposed to the otherwise quite advanced and Idea-Song-Oriented Xenos Culture. Rhea live off herbs and distilled Emotion, often developed Alchymerically, much like their Moa ancestors. Their research is very hands-on, quite pre-Renaissance - lots of dissection and exhibition.
Rhea wear an object individual to each person they knew who has ever died. They do not see this as corpse-robbing, but hands-on research. Particularly well studied / elder / unfortunate Rhea are covered in small trinkets.
Rhea, like Emus, don't really do standard gender - they see others as either "Soft" or "Sharp", based on the image and reaction they portray. A Soft person drifts on through life leaving no marks, but a Sharp one leaves a mark. Soft subjects hold no interest for an amorous Rhea.