What is described as an even marking of color around both eyes, such as seen in Checkered Giant rabbits?

The term associated with an even marking of color around both eyes, as observed in Checkered Giant rabbits, is eye circle. This distinctive marking enhances the overall appearance of the rabbit and can be a recognized feature in specific breeds. It is a trait breeders and judges often look for in exhibitions and competitions, as it contributes to the breed's standard.

The other options pertain to different concepts or health issues. Eye stain usually refers to a discoloration caused by tear staining, which is associated with hygiene rather than a breed characteristic. Eye color simply refers to the pigmentation of the eyes, which doesn't encompass the specific marking feature. Ear canker, on the other hand, is a condition affecting the ears of rabbits, characterized by infection or infestation, and is unrelated to markings around the eyes. Understanding these distinctions helps clarify why eye circle is the accurate answer in this context.