Wing bars, eye-lines and eye-rings, breast markings, tail spots, and bill and leg color can usually separate even very similar birds.
Bell's vireo, Red-eyed vireo—eye-ring or eye-line
Eastern phoebe, Eastern wood-pewee—plain wing or wing bar
Wood thrush, Brown thrasher—breast spots or breast streaks
Every bird species has its own ID clues
Every bird species exhibits its own identification clues, including all of the following: size and shape, color and field marks, songs and calls, behavior traits and habitats where they are most likely to be found. Some species can be identified from just a few clues. Others require careful observation of every detail and every trait.
How big is a certain bird compared to one you already know, such as . . .
A house sparrow?
Is it . . .
Slender as a mockingbird?
Chunky as a meadowlark?
Is its bill . . .
Fine, as a warbler's?
Cone-shaped, as a cardinal's?
Thicker, as a vireo's?
Are its wings shaped like those of . . .
A Forster's tern?
A northern bobwhite?
A red-tailed hawk?
Is its tail like that of . . .
A barn swallow?
An eastern bluebird?
A blue jay?
Does it catch insects during short flights like a flycatcher, or during long flights like a swift? Does it glean food from the bark of trees like a nuthatch?
Great crested flycatcher
Does it cock its tail like a wren, flip its tail like a phoebe, or bob its whole body like a waterthrush?
Other Clues to Identification
Knowing what to expect WHEN:
One of the clues to identifying birds is to know what to expect seasonally. For example, the chipping sparrow and the American tree sparrow look similar. Both have wing bars, eye-lines and plain breasts. The chipping sparrow, however, is a summer resident while the American tree sparrow occurs in Missouri only in winter.
Knowing what to expect WHERE:
Each species of bird is associated with a particular habitat or habitats. Habitats usually have certain vegetative or landform characteristics that provide the species food and shelter. Knowing the habitat associations of a species enables you to know where to look for it. Generally, the more habitats you visit, the more kinds of birds you will see. An understanding of habitat associations also will enable you to know what to expect where, and can, therefore, be used to identify birds.
For example, although the upland sandpiper and greater yellowlegs are somewhat similar in appearance, the upland sandpiper is found on grasslands, while the yellowlegs is usually found along shorelines when in Missouri.