Western white-bearded wildebeest (Connochaetes mearnsi). Photo © Stefan Swanepoel
Eastern white-bearded wildebeest (Connochaetes albojubatus) adult male. Photo © Paul Mannix · Wikimedia Commons · CC BY-SA 2.0
Two species of white-bearded wildebeests in East Africa have diverged categorically in how they achieve whole-body conspicuousness at a distance.
Although both rely on gloss-versus-gloom effects as well as pigmentation, the western species looks dark overall whereas the eastern species looks pale overall.
This fits an overall pattern seen in migratory hoofed mammals adapted to either mesic or semi-arid habitats.
Figure 1. Eastern white-bearded wildebeest (Connochaetes taurinus albojubatus) [photo from Zooinstitutes]
Figure 2. Western white-bearded wildebeest (Connochaetes taurinus mearnsi), Ngorongoro, Tanzania. Photo by D. Gordon E. Robertson
Robin and the Honey Badger, 22 March 2016