Identify Birds in Flight

Many birders, especially novices, have trouble identifying birds in flight when they may only get a glimpse of a moving bird without time to note field marks. Learning how to identify birds in flight is not difficult, however, when you know what clues to look for as the birds fly by.

Equipment to Identify Birds in Flight

Having the proper tools is essential to confidently identify flying birds. Well-equipped birders will have:

• Binoculars: Birding binoculars with a wide field of view are best for in-flight identification since they allow easier tracking of the bird as it moves across the sky or in and out of brush. The optics should also be properly coated to reduce sun glare. Spotting scopes are not typically useful for identifying birds in flight since the birds will move out of a scope's view more quickly and the equipment cannot be shifted as easily to follow their flight path.
• Field Guide: Choosing a field guide that features photos or drawings of birds in flight will help with accurate identifications. Flying birds may have very different body shapes than when they are perched, and field marks on the wings and body can look different in flight. Most field guides do provide at least representative flight poses for many birds, but those with extensive flight views will be more useful.
• Hat: A hat with a wide brim to shield the eyes from the sun is ideal for identifying flying birds, as it will allow longer views as the birds move across the sky without causing eye strain. Choose a hat with proper crown ventilation and a comfortable fit for the best use.

Identifying Birds in Flight

While a flying bird may only give a birder a fast glimpse of field marks, it still presents many clues that can be used to successfully puzzle out the bird's identity. When trying to identify a bird in flight, look for:

• Wing Shape: How long and wide are the wings? Do the primary feathers splay or are they held close together? Do the trailing edges of the wings have a bulge or are they straight? Are the wingtips pointed, rounded or blunt?
• Wing Markings: What color are the wings? Are there color patches on the tops or undersides of the wings? Are there wrist markings? Are there stripes, streaks or spots on the primary or secondary feathers? How do the leading and trailing edges compare in color?
• Body Shape: What size and shape is the body when compared to the wings? How are the head and legs held in flight? What is the wing position when seen head-on or from below?
• Body Markings: Are there distinct streaks, spots or color patterns on the abdomen, tail, chest, undertail coverts or legs? Are there any contrasting areas of color visible on the body?
• Tail: How long is the tail? Is it forked, wedged, rounded or blunt? Is there a subterminal band or other streaks or bands? What overall color is the tail?
• Wing Rhythm: Is the bird soaring, gliding or actively flapping its wings? How fast is it flapping? Is the flap rhythm changing?
• Flight Path: What direction is the bird flying? Is it traveling a straight path or turning in circles? Is it hovering, diving or undulating in flight? How does the flight path compare to the wing rhythm? When flying straight, is the bird level or rocking side to side?
• Sounds: Is the bird making any noise in flight? Is it calling? Do the wings make distinctive sounds?
• Behavior: What is the purpose of the bird's flight? Is it migrating, hunting, hawking, gathering nesting materials, courting a mate or foraging?
• Flock Size: Is the bird flying alone or in a flock? How many birds are in the flock? Is the flock traveling in a coordinated shape or pattern? Are the birds in the flock different species?

While one quick fly-by of an unidentified bird may not yield answers to every question, knowing what to look for can help birders gather enough clues about a flying bird to determine what species it is.

Tips for Identifying Birds in Flight

Flying birds present a lot of challenges for identification: quick views, poor lighting, distance, and continual motion. It is not impossible to identify flying birds, however:

• Observe familiar birds in flight first. This is good practice for noting the changes in shape and behavior between perched views and flight views and gives birders additional practice adjusting their optics to observe moving birds.
• Be patient when watching flying birds. Over time, birders can develop personal tricks for best identifying flying birds, and birds in flight may cooperate more on different occasions by moving closer, changing position or otherwise offering a better view.
• Don't try to identify every bird. While it can be tempting to take only quick looks at every bird in a flying flock, focus instead on observing one individual in more detail to be confident about an identification.

Identifying birds in flight can be a challenge for many birders, but it is not impossible. By knowing what to look for and how to observe flying birds, even a beginning birder can see plenty of clues to confidently identify birds with only a quick in-motion glance.