Birds that have a black stripe across their eyes, otherwise known as an eye line or loral stripe, give bird-watchers an extra characteristic to look out for in identifying different species. A loral stripe is commonly found among songbirds and birds that are native to North America. The loral stripe begins between the eyes and extends across the head. In some species the loral stripe has special feathers or loral bristles which are slightly different than the surrounding feathers. It often appears very faint until a bird reaches its adulthood at which point the stripe becomes distinct.
There are more than three dozen types of sparrows in North America alone, which can be difficult to classify due to the similarities in their looks. Three types of sparrows that have distinct black lines on their crown and across their eyes are the chipping sparrow, the white-crowned sparrow and the white-throated sparrow. The horned lark, which is the only true native ark to North American and is sparrowlike in its appearance, also has a distinctive black stripe across its eyes.
Of the chickadee family, the Mountain chickadee and the Bridled titmouse have the true black stripe across their eyes. Both the Black-capped and Carolina chickadees have a similar look, but the black stripes extend from the eyes to the crown of the head, forming a full black cap.
Many Woodpeckers have black and white patterns so it is common to see types that feature either black caps, black and white checks, or black stripes on their heads. The Hairy woodpecker, Nuttall's woodpecker, Red-naped sapsucker, Yellow-bellied sapsucker, Pileated woodpecker and the Downy woodpecker all have black stripes across their eyes.
Other types of North American birds that are marked with a black eye line include the Eastern meadowlark, the Black-throated Gray warbler, the Northern cardinal and the Chukar, which is a chickenlike game bird that is native to Southern Eurasia but populates rocky terrains in the Western U.S. and Southern Canada.