So for example, the male Yellow-breasted Chat has a yellow breast (pretty obvious), but its potential mates or rivals also see ultraviolet feathers on his chest that set him apart from the females of the species. The theory was again proven in another study in which scientists placed taxidermied male and female Chats in the wild to see how their living counterparts would react. Males stayed true to their territorial nature and attacked the stuffed male Chats and tried winning over the taxidermied females. Thus, they obviously were seeing something that the researchers couldn’t.