The colouration, or lack thereof, of the European bison
The European bison (Bison bonasus) is not as photogenic as might be expected for its impressive profile. It is disappointingly plain (e.g. see https://www.inaturalist.org/observations/68748464), lacking even the countershading expected in dull-coloured animals (see https://en.wikipedia.org/wiki/Countershading).
Other large bovines have intriguing patterns. For example, the gaur (Bos gaurus) shows a contrast between the blackish body and the pale horns, ears, lower legs, and rhinarium (see https://www.inaturalist.org/photos/79457298). The banteng (Bos javanicus) has whitish buttocks and lower legs. The water buffalo (Bubalus arnee) has pale markings on the ears, lips, neck and lower legs (see https://www.alamy.com/stock-photo-wild-water-buffalo-bubalus-arnee-adult-male-standing-in-grassland-77481628.html).
However, there is one easily overlooked accentuation in the colouration of the European bison. During summer its medium-tone uniformity blends into the forest, but in winter - when the environment pales and even whitens with snow - it actually darkens, particularly on the side of the face. The resulting contrast makes the species relatively photogenic in the cold season (e.g. see https://wallhere.com/en/wallpaper/686687).
This seasonal change brings the European bison towards conformity with a pattern seen throughout the year in several other species of large bovines. Both the Cape buffalo (Syncerus caffer caffer, see https://www.alamy.com/large-herd-of-african-buffalo-syncerus-caffer-grazing-on-the-open-plain-of-serengeti-national-park-tanzania-image226007961.html and https://www.freepik.com/premium-photo/buffalo-herd-within-volcano-ngorongoro-tanzania_11361020.htm#&position=8) and the river buffalo (Bubalus bubalis, see https://culturecheesemag.com/farm-animal/water-buffalo-cheese/) are so dark that they achieve conspicuousness in typical grassy environments; presumably this reflects the nature of the extinct ancestor of the river buffalo. The same applies to the plains bison (Bison bison bison), the dark, massive head of which stands out from grassland whether green or frost-bleached (see https://wp.nathabblog.com/wp-content/uploads/2012/04/Colin-McNulty-YellowstoneBison1_Web.jpg).
Wherever large bovines congregate in open environments, they seem to adopt large-scale darkness in aid of adaptive conspicuousness. In their self-advertisement they take after many other gregarious species of ruminants from Thomson's gazelle to oryxes, which have similarly forsaken attempts to hide from predators. However, unlike the large bovines, antelopes and deer stand out by virtue of whitish features as much as dark ones. The most photogenic species of all are those achieving pied patterns by means of large patches of whitish and blackish (e.g. bontebok, Damascus pygargus pygargus, see https://blog.nature.org/science/files/2015/07/bontebok.jpg).
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