Field guides describe birds part by part: "rusty eyeline," "two buffy wing bars," "chestnut undertail coverts." Cornell's All About Birds lists the main divisions of a bird as the bill, head, back, throat, breast, wings, tail and legs, and the finer field marks sit inside those. This page puts the common terms on one labeled drawing, defines each in plain words, and gives a backyard bird where the mark helps. Use it alongside bird identification basics, which covers the bigger picture first.
The six terms beginners meet first
Wing bars: stripes across the folded wing (All About Birds). Eye ring: a ring of color around the eye (All About Birds). Supercilium: the eyebrow stripe over the eye (All About Birds, Cornell Bird Academy).
Malar stripe: a stripe angling back from the chin that separates cheek from throat, also called a whisker or mustache mark (All About Birds). Primaries: the long flight feathers on the outer half of the wing (All About Birds). Undertail coverts: the feathers between the vent and the base of the tail, on the underside (Oklahoma State University Extension).
Swipe the drawing sideways to see all the numbers.
- Crown: top of the head.
- Supercilium (eyebrow): stripe over the eye.
- Eye ring: ring of color around the eye.
- Eye line: line through the eye.
- Lores: between the bill and the eye.
- Bill: upper and lower mandible.
- Ear coverts (auriculars): feathers behind the eye that cover the ear opening.
- Malar stripe: whisker or mustache mark from the base of the bill.
- Throat
- Nape: back of the neck.
- Back
- Wing coverts: small feathers at the front of the wing.
- Wing bars: stripes across the folded wing.
- Secondaries: inner flight feathers.
- Rump
- Primaries: outer, longest flight feathers.
- Tail (rectrices)
- Undertail coverts: between the vent and the tail base, below.
- Sides (flanks)
- Belly
- Breast
Head terms
| Term | What it is | Backyard example |
|---|---|---|
| Crown | Top of the head (Cornell Bird Academy) | Chipping Sparrow's rufous crown (Cornell Bird Academy); American Tree Sparrow's rusty cap, year-round (FeederWatch) |
| Supercilium | The eyebrow: runs from above and in front of the eye to the back of the head (Cornell Bird Academy) | Chipping Sparrow's distinct white eyebrow (FeederWatch); the bright white eyebrow of a female Purple Finch (FeederWatch) |
| Eye line | Runs from the bill back through the eye toward the back of the head (Cornell Bird Academy) | Black or dark brown on a Chipping Sparrow, rusty brown on an American Tree Sparrow (FeederWatch) |
| Eye ring | A ring of color around the eye (All About Birds); a bold, contrasting group of feathers or skin (Cornell Bird Academy) | Ruby-crowned Kinglet's bold white eye-ring (Audubon); a pale eye ring sometimes shows on a female Cassin's Finch (FeederWatch) |
| Lores | The area between the base of the bill and the eye (All About Birds, OSU Extension) | The yellow spot before the eye of a White-throated Sparrow (Audubon) sits in this area |
| Ear coverts | Small feathers behind the eye that cover the ear opening (Wikipedia); also called auriculars (Cornell Bird Academy) | Gray ear coverts on a Chipping Sparrow (Cornell Bird Academy) |
| Malar stripe | A line angling back from the chin, separating cheek from throat; also whisker, mustache or moustache (All About Birds) | Male Northern Flicker: black mustache in the eastern Yellow-shafted form, red in the western Red-shafted form (Audubon) |
| Throat | Below the bill; the breast begins below it (Wikipedia) | White-throated Sparrow's conspicuous white throat (Audubon) |
| Nape | The back of the neck (Wikipedia) | Male Downy Woodpecker's red nape spot (Audubon) |
| Bill | Upper and lower mandible (Wikipedia, OSU Extension) | American Tree Sparrow: dark upper mandible, yellow lower mandible (FeederWatch) |
Two variations are worth knowing. A white ring that continues over the bill, so the bird looks as if it wears glasses, is called spectacles; the Blue-headed Vireo has them (Cornell Bird Academy). A pale stripe only above the lores, not behind the eye, is a supraloral (Wikipedia).
Wing terms
Three groups of wing feathers come up again and again in field guides.
- Wing coverts. OSU Extension calls them the small feathers at the front of the wing, covering the bases of the primaries. Wikipedia names the rows: greater coverts (the outermost, largest row), then median, then lesser.
- Secondaries. The inner flight feathers, between the primaries and the body (OSU Extension); they attach to the ulna (Wikipedia). On many ducks a colored patch of secondaries, the speculum, helps with ID (All About Birds).
- Primaries. The outer flight feathers and the longest of the wing feathers (OSU Extension). They attach to the bird's "hand," and most passerines have ten (Wikipedia).
Tertials sit beside the secondaries, nearest the body. A USGS Patuxent glossary defines tertiary feathers as those adjoining the secondaries; Wikipedia adds that some authors use the word for a songbird's innermost secondaries.
Wing bars are stripes across the folded wing (All About Birds); OSU Extension describes them as running across the shoulder of the wing and notes them on warblers and vireos in particular. Backyard examples:
- American Tree Sparrow vs Chipping Sparrow: two white wing bars and a rusty shoulder patch on the tree sparrow; two buffy wing bars and a plain gray shoulder on the Chipping (FeederWatch).
- American Goldfinch: bold white or buff wing bars on black wings; winter birds vary from yellowish-brown to gray (Audubon).
- Ruby-crowned Kinglet: usually one strong white wing bar, with a black bar just behind it (Audubon).
Body and tail terms
| Term | What it is | Backyard example |
|---|---|---|
| Back | The upperparts between the mantle and the rump (Wikipedia) | — |
| Rump | Above the base of the tail, after the back (OSU Extension diagram; Wikipedia) | Male Cassin's Finch: brown back fading into a pinkish rump (FeederWatch) |
| Breast | Between the throat and the belly (Wikipedia) | American Tree Sparrow: grayish breast with a central spot, sometimes hidden (FeederWatch) |
| Belly | Between the breast and the vent (Wikipedia) | — |
| Sides (flanks) | Called "sides" in FeederWatch's descriptions | Male House Finch: conspicuously streaked sides (FeederWatch) |
| Undertail coverts | Feathers in a triangular area under the bird, between the vent and the base of the tail (OSU Extension); together called the crissum (Wikipedia) | Gray Catbird: chestnut undertail coverts on a smooth gray bird (Audubon) |
| Tail | Long feathers extending from the rear (OSU Extension); the tail feathers are rectrices, paired, and most species have six pairs (Wikipedia) | Downy Woodpecker: black bars on white outer tail feathers (Audubon) |
The undertail is a good place to look on brown finches. FeederWatch describes broad dark streaks under the tail of a House Finch, well-defined dark streaks on a Cassin's Finch, and a Purple Finch undertail that is usually white with no streaks, which it calls diagnostic if visible. More on those three in the House Finch profile.
Where terms differ
- Malar. All About Birds uses "whisker mark," "mustache" and "malar stripe" for the same stripe. Cornell Bird Academy uses "malar" for the white area just below the ear coverts, bordered by a fine blackish line. FeederWatch describes a male Purple Finch's malar stripe as a line extending backward from the lower base of the bill.
- Eyebrow. All About Birds' field-marks page gives "eyebrow stripe" and "superciliary"; Bird Academy and Wikipedia use "supercilium." They mean the same stripe.
- Tertials. Counted as separate from the flight feathers by Wikipedia, which notes they are not considered true remiges, but treated as the innermost secondaries by some authors.
How to use the terms at the feeder
Take one bird at a time and run head to tail, noting only what you can see. The backyard sparrow ID page uses exactly these marks: crown color, eye line, wing bars and breast spot.
- Head: crown color, eyebrow, eye line, eye ring, anything on the lores
- Face and throat: ear coverts, malar stripe, throat color
- Bill: shape, and whether the two mandibles differ in color
- Wing: how many wing bars, their color, any shoulder patch
- Underparts: streaks or a spot on the breast, streaks on the sides
- Tail: length, white edges or corners, streaks under the tail
OSU Extension also groups birds by bill shape: sparrows, juncos and finches have short, stubby bills for cracking seeds, and woodpeckers have long, thick, chisel-like bills. Note the bill before the bird flies. Then log what you saw in the streak tracker, and try the terms on another look-alike pair in Downy vs Hairy Woodpecker.
Sources
- Bird ID Skills: Field Marks — All About Birds, Cornell Lab of Ornithology
- Inside Birding: Color Pattern — Chris Wood and Jessie Barry, Cornell Lab Bird Academy
- I Think It Is A… (4H-NREM-622, PDF) — Kevin Allen and Dwayne Elmore, Oklahoma Cooperative Extension Service, Oklahoma State University
- Patuxent Wildlife Research Center glossary (archived 2008) — U.S. Geological Survey
- American Tree Sparrow and Chipping Sparrow — Project FeederWatch
- Cassin's Finch, House Finch, and Purple Finch — Project FeederWatch
- Audubon Guide to North American Birds: Gray Catbird, White-throated Sparrow, Northern Flicker, Ruby-crowned Kinglet, American Goldfinch, Downy Woodpecker — National Audubon Society
- Glossary of bird terms, Covert feather, Flight feather, Supercilium and Nape — Wikipedia (secondary)