Identifying a bird by its silhouette is one of the most commonly used tools in bird watching. This involves learning the size and shapes of the different types of birds and then being able to put this information to use in the field when a bird comes along that the person does not recognize. A field guide to bird species or an online site can be utilized to learn the different shapes that birds present from a distance. Having the ability to know what size a bird is becomes paramount when using this tool to identify birds. By comparing the size of an unknown bird to a bird with similar colors that the observer is familiar with is useful, as is comparing the bird's size to that of a commonly known bird such as a sparrow or blue jay. Paying attention to the size and shape of such features as the legs, bill, and wings of a bird also aid in identifying it.
The color patterns of a bird's feathers are another identification tool. Birds rarely simply sit right in front of the observer and allow a long look but even a quick glance at a bird as it flits by can give the bird watcher an idea of its overall colors. Factors such as a bird's age, whether it is molting, the lighting condition under which the bird was seen and the condition of its feathers may make it hard to match a bird to its picture in a field guide immediately. The bird watcher will pay attention to light and dark patterns on a bird and then, when a better view of the specimen is allowed, the focus will turn to how bright or dull the individual colors are. Some birds, such as the northern cardinal or the oriole, are so brightly colored that an instant identification can be made by using the color pattern tool.
The behavioral patterns of a bird are extremely valuable in helping to identify it. Birds of different species do not all act the same. Some have behaviors unique to their own species that can allow other potential species to be eliminated quickly when trying to identify them. It is important to observe the behavior of a bird for an extended period of time if possible as this will give the bird watcher a better grasp of what the bird is doing and help to identify it. How a bird moves is one facet of its behavior. Birds can dart from place to place, hop, go up and down a tree or dive into the water. The flight pattern is another vital piece of the puzzle in bird behavior. Flying in a straight line, with an up-and-down motion, in circles and soaring without flapping the wings are all clues to a bird's identification. Any bird that can be observed eating will give information to the observer by how it does so. Swallows, for example, will fly through the air grabbing insects in acrobatic moves while herons will remain motionless along the shore and then grab a frog with their long bill. These behaviors must be documented so the observer then can use them later on when consulting a field guide or reference site that describes them.
While most bird identification tools depend on observing the specimen, one does not. Identification is possible by listening to the song or call of a bird. Beginners need to watch a bird closely and if it is singing or calling out a connection will be formed between that bird and its sound. It's possible to access tapes or websites which have recorded songs and calls of birds, thereby identifying the bird by its song. It is also prudent to listen to a bird's call and then try to put it into words. The chickadee's trademark call of "chick-adee-dee-dee" cannot be mistaken for anything else.
Nothing the habitat the bird is observed in is a highly effective tool in aiding identification. Field guides and online sites all have range maps which will show what part of the United States various bird species inhabit. These maps further show where the bird will spend its winters. Besides the geographical location of the bird, there is the type of terrain and habitat it is seen in. Bird watchers will record if a bird was seen in deep forests, grasslands, on the water, in an urban setting or near a shoreline while trying to identify it. A person will enter a specific habitat with an idea of what types of birds may live within it, which expedites identification. For instance, a wading bird would not be found in a forest setting where there is no water, while a hawk would not be found sitting on the ground in the middle of a city block.