Final answer:
The black line through the eye and the white stripe above it on a Chipping Sparrow are known as eyebrow stripes, which are used to identify different bird species.
Step-by-step explanation:
The black line through the eye and the white stripe above it on a Chipping Sparrow are called eyebrow stripes. These markings are distinctive characteristics that help in the identification of bird species. The eyebrow stripe is often used by ornithologists and bird watchers to differentiate between similar species and is commonly seen in many bird species beyond just the Chipping Sparrow.