Bird watching is a popular hobby that allows people to connect with nature and witness incredible biodiversity. However, identifying birds correctly can be challenging for beginners. There are over 10,000 species of birds worldwide, many of which look similar at first glance. Fortunately, there are techniques birders can use to accurately identify the birds they see.
When trying to identify an unknown bird, there are four key factors to look for:
Size and Shape
Paying attention to a bird’s overall size and proportions is extremely useful for narrowing down possibilities. Birds come in a huge range of sizes – the Bee Hummingbird is only 5-6 cm long, while the Ostrich can reach 2.7 meters tall. Within the same family, body size can help distinguish similar species. For example, American Robins are chunkier with a rounder body shape than Eastern Bluebirds.
Also look at the bird’s silhouette in flight. Soaring hawks have a very different shape than small darting songbirds. The shape and length of key features like the neck, tail, wings, and bill offer additional clues to the bird’s identity.
Use Size to Identify Shorebirds
Shorebirds can be notoriously difficult to tell apart, as they are mostly various shades of brown and grey. However, there are noticeable size differences between types of shorebirds. The very largest like Marbled Godwits may be up to 50 cm long. Medium-sized Semipalmated Plovers and Least Sandpipers are 15-20 cm. The smallest Semipalmated and Western Sandpipers may only be 11-13 cm.
Color Pattern
Plumage color and pattern can be the easiest way to identify many species. Start by looking at the bird’s main body areas – the head, breast, belly, back, and wings. Note the main color shades and any distinctive markings. Is the breast streaked or spotted? Is the head a different color than the body? Many birds will also show prominent patches of color on areas like the rump, shoulder, or throat.
Be aware the male and female can sometimes have dramatically different plumages in a species. males are often more brightly colored to attract mates. Younger birds may also look completely different from adults.
Use Field Guides to Match Color Patterns
Field guides will have illustrations of birds sorted by color pattern that you can match to what you see. So if you notice a small grey bird with a rusty colored tail, you can flip to the section on gray and rusty orange birds to narrow down the possibilities. Guides will also indicate if there is sexual dimorphism or changes between juvenile and adult plumages.
Behavior
A bird’s behavior, movement patterns, and posture give essential identification clues. Carefully observe how it’s moving through its environment. Does it mostly hop along the ground? Flit quickly from branch to branch? Wade slowly through water? Specific types of flight patterns are also useful to note – does it take off in bursts or sustained glides? Is the flight style straight, bounding, or zig-zagging?
Feeding behavior can be very telling as well. Watch for behaviors like wading, surface seizing, diving, hawking insects, probing flowers, bark gleaning, and more. The places different species feed in can also indicate their identity. For example, nuthatches and woodpeckers feed on trunks and branches, while flycatchers catch insects from exposed perches.
Use Behavior to Identify Ducks
While ducks may look very similar, their behavior offers helpful differences. River ducks like Mallards tip downwards to feed underwater. Eiders float on the surface and dive straight down to feed. Stiff tails help stiff-tailed ducks like Ruddy Ducks spring straight up when diving. Knowing these characteristic behaviors helps distinguish lookalike species.
Habitat
Pay close attention to the exact setting and habitat you observe a bird in. Consider the details of the location – is it forested or open? Near water, shrubs, fields? What types of plants are present? Pay attention to both large-scale habitats like beaches, meadows, and swamps and small-scale perching spots and nest sites.
Certain species strongly associate with and even specialize in specific habitats or niches in their environment. Becoming familiar with these tendencies will give you a major clue about an unknown bird’s identity. For example, hearing an unseen songbird in pine woods helps narrow the possibilities to pine forest specialists.
Use Habitat to Identify Sparrows
Most sparrows have similar plumage but prefer different habitats. Chipping Sparrows live in open wooded areas, while Swamp Sparrows stick to marshes. Savannah Sparrows inhabit open grassy fields. If you note an unidentified sparrow in a salt marsh, chances are it’s a Seaside Sparrow.
Putting the Keys Together
Individually, size, color, behavior, and habitat provide helpful clues about a bird. However, the most powerful identification approach combines observation of all these factors together. For example, noticing a small grey bird with a rusty tail perched on power lines near a stream gives much more information than just the color pattern alone. Layer the four keys together to zero in on the species most likely to match what you observe.
An Identification Example
You catch a glimpse of a small grey-and-rust colored bird, about sparrow sized, fluttering out from a brushy area to briefly perch on a bare branch before returning to the bushes. Mentally go through the four factors:
- Small size, about 10-15 cm
- Grey upperparts, rusty reddish tail
- Flying and perching with quick, fluttering wingbeats
- Brushy, scrubby habitat near an open field
Considering all these together, your best guess would be a Common Yellowthroat, a small warbler species that fits the descriptors well.
Beyond Visual Identification
While strong visual identification skills are essential, they have limitations. Many birds simply cannot be reliably told apart by sight alone – even expert birders may need to consult other clues. Going beyond visual ID factors can help confirm hard-to-identify species:
- Calls and songs – learn the characteristic vocalizations which are often the best way to distinguish similar birds.
- Range and season – narrow down when and where species occur to determine what’s possible.
- Behavior – look for specific courtship displays and interactions.
- Plumage details – sometimes close inspection of a single feather can clinch an ID.
- Reference photos – compare images of subtly different species side-by-side.
Improving Your Skills
Identifying birds by sight alone takes patience and practice. But anyone can improve their skills with some dedicated effort. Here are some tips for taking your visual ID abilities to the next level:
- Study field guide illustrations and photos closely to become familiar with key species.
- Refer back to guides frequently when you first start out.
- Quiz yourself by covering the captions on photos and trying to ID species.
- Go over misidentified birds you photograph to sharpen your eye.
- Bird with more experienced birders who can teach you new tricks.
- Focus on mastering one group (like warblers) at a time.
- Practice predictive identification – try IDing a bird before seeing the whole thing.
With regular practice over time, you’ll develop stronger search images for the unique traits of each species. You’ll start to recognize birds instantly instead of seeing a confusing jumble of feathers. Paying attention to size, shape, color, behavior, habitat, and other signals will become second nature. Sharpening your skills takes patience, but the payoff is well worth it.
Conclusion
Identifying birds by sight alone is both challenging and rewarding. While it may seem impossible for beginners, using four key factors makes the process much more manageable. Pay close attention to a bird’s 1) size and shape, 2) color patterns, 3) behaviors, and 4) habitat. Combine these visual clues to narrow down the possibilities to a most likely matching species. And remember that even experts rely on non-visual cues to confirm IDs when needed. With practice over time, anyone can become proficient at this essential birdwatching skill.
