Auricular semets in Cervus, Rusa and Axis but not other cervine deer

In my last Post (https://www.inaturalist.org/journal/milewski/55639-auricular-semets-in-alces-and-odocoileus-but-not-other-odocoileine-deer#), I showed that auricular semets in odocoileine deer are virtually restricted to two genera, namely Alces and Odocoileus.

Here I examine the other major subfamily of deer for auricular semets. Once again, I show only females, excluding winter coats.

What emerges is as follows. The only two genera with obvious auricular semets are Cervus (all species and most subspecies) and Rusa (only one of the four species). A third genus, namely Axis, has a subtle auricular semet.

Taking all deer together, what this means is that Cervus is the preeminent genus with respect to auricular semets. Then follow the genus Alces and the species Rusa unicolor.

However, in Elaphodus cephalophus the ear as a whole has conspicuous colouration. It is unclear whether this constitutes an auricular flag, or an auricular semet, or both.

In summary, the two major subfamilies of deer are similar in that most genera, species and subspecies lack auricular semets. It remains to be investigate

what the auricular semets communicate in Cervus, Alces, Odocoileus, Rusa and Axis,
why these are the main genera featuring auricular semets, and
to what extent patterns convergent with these deer have evolved among bovids.

Cervus canadensis:
(covered in a previous Post)

Cervus elaphus:
https://lightfieldstudios.net/246900816/stock-photo-close-red-deer-hind-green.html and https://www.pikist.com/free-photo-iafkl and https://photostockeditor.com/premium/278017945/deer-face-and-head-close-up-of-red-deer-female-looking and https://www.reddit.com/r/AllAboutNature/comments/jfls3d/chipmunk_or_deer_an_amazing_picture_of_a_red_deer/ and https://www.inaturalist.org/observations/89836390

https://www.inaturalist.org/observations/72678905

Cervus nippon:
https://www.istockphoto.com/photo/a-deer-with-defocused-people-in-the-background-gm826605522-134449679 and https://www.istockphoto.com/photo/fallow-deer-gm1143078489-306846447 and https://www.pxfuel.com/en/free-photo-oxzpe and https://www.dreamstime.com/portrait-roe-deer-portrait-beautiful-roe-roe-deer-lithuanian-forest-image163280327 and https://www.freepik.com/premium-photo/chital-cheetal-spotted-deer-axis-deer-national-park-thailand_14756491.htm#&position=0

https://pxhere.com/en/photo/729616 and https://www.dreamstime.com/stock-photo-young-fallow-deer-animal-male-nature-zoo-image44977633 and https://www.dreamstime.com/eld-s-deer-panolia-eldii-eld-s-deer-panolia-eldii-also-known-as-thamin-brow-antlered-deer-endangered-species-deer-image138932251

https://www.istockphoto.com/photo/close-up-of-fallow-deer-head-gm498401388-79628877

Cervus albirostris:
https://www.stockfreeimages.com/6041103/Female-White-lipped-Deer.html and https://www.youtube.com/watch?v=GSQre1Gch98

Elaphurus davidianus:
https://www.dreamstime.com/female-pere-davids-deer-summer-hot-day-posing-zoo-enclosure-image101723402