When birders only have a split-second view of a bird in the field, what should they be looking for to properly identify the species? Understanding the top parts of a bird for identifiable field marks is the best way to learn how to scan the bird's appearance and focus quickly on key areas that can help you identify the bird. While checking more than a dozen areas on a small bird's body may seem impossible, many birds lack marks in every area and noting where marks are visible can mean the difference between not knowing what the bird is and being able to accurately identify it.
The Most Important Field Mark
The most critical field mark to note about any bird you see is its overall shape. Even the fastest glimpse of the shape can help you identify the type of bird you are looking at: ducks, gulls, hummingbirds, warblers, woodpeckers and more all have very distinct shapes. Of the hundreds of bird species you may see in one area, noting the bird's shape can help you immediately eliminate most birds as you narrow down the individual in question to one identified species. It is possible to judge a bird's shape even with a distant, indistinct view, and once you know what type of bird you are looking at, you can more easily look at all its specific field marks for a precise and accurate identification.
Key Bird Field Marks
When studying a bird for field marks, it is best to sweep from bill to tail and note any markings in these key areas.
- Bill: Note the length, color and shape of the bill. Note whether it is straight, upcurved or decurved, its thickness and how its shape changes along the length.
- Crown: Check for different colors on the bird's crown, and note the shape of the crown feathers, such as whether they extend into a crest or plumes.
- Eyes: Note the eye color and any surrounding markings such as an eye line, eye ring or eyebrow. Also note the lores in front of the bird's eyes and check if the markings combine to create a “spectacles” effect on the bird's face.
- Auriculars: Check the bird's cheeks for a different patch or wash of color, and note if that color matches other colors on the bird's head or body.
- Nape: Check the nape for a patch of color and note if that color extends to the bird's crown or down onto the back.
- Throat: Note different colors or markings on the throat, and compare the color to the sides of the neck and the upper breast.
- Back: Check the color on the back and note any spots, streaks or mottling. Also note how much the back color may contrast against the head or wings.
- Chest: Look carefully at the breast for any color change or specific markings, such as streaks, spots or a faint color wash. Note whether any markings are just on the chest or if they extend along the flanks, throat or abdomen.
- Wings: Check the wings for overall color as well as specific markings such as wing bars, different colors along the edges of the feathers or color patches when the wing is spread or folded. Note the length and shape of the wings.
- Flanks: Check the sides of the bird's body for color patches or markings.
- Abdomen: Check low on the belly for additional markings or color changes compared to the rest of its plumage.
- Legs and Feet: Note the color of the legs and feet, and if possible, not the thickness of the limbs and the size of the talons. Also check for any feathering along the legs, particularly in raptors.
- Undertail Coverts: Check the patch of feathers beneath the tail for different colors or markings that can help distinguish the species.
- Tail: Note the length of the tail and its overall shape, particularly at the tip. Look especially at the outside feathers for different colors, as well as for colored tips or other markings along the length of the tail, such as narrow stripes or wider bars.
At first glance, it can be intimidating to check all these areas on a single bird with a single look, but with practice any birder can learn how best to note field marks on each bird they see. Very few birds have unique markings in every area, and noting just a few of the key marks will help make bird identification much simpler – once you know what to look for.
Photo – Cape May Warbler © Bill Majoros