(50 points)
excerpt adapted from what is that bird?
by the u. s. fish and wildlife service

the first step in bird identification is learning to observe. watch, listen, and record your observations in a journal using descriptive words and sketches, or photograph birds to capture a permanent, detailed image that you can study later.
if you are just starting to watch birds, consider familiarizing yourself with the ones that you see daily. what are their general characteristics? are they big or small, colorful or drab? do they sit still or flit from branch to branch? then, try comparing new birds that you see with the common birds that you already know. is your new discovery the size of a sparrow, a robin, or a crow? is its bill short or long, hooked or straight?
learning the basic form and structure, or morphology, of a bird will you to make comparisons of birds. concentrate on the shape and size of the beak, including the relative size of the upper and lower beak; length of the outer tail feathers, upper tail coverts, and throat; and the coloration of the crown and breast. it will also you to think about the types of habitat in which you are most likely to find specific birds, since the birds that you see may be migratory and will only be in your area at a specific time of the year.

some people can identify a bird just by its song or call. once you start to listen to the calls around you, you will start to learn them, too. do you know any memory devices that could you recall a song or call and identify the bird associated with it? can you distinguish differences in rhythm, pitch, tone, and repetition?
studying the behavior of a bird is also often in identifying it. knowing characteristic bird behavior can be an important aspect of bird conservation and management, since erratic behavior can signal a stressed or unhealthy bird. because birds move around a lot, they can be vulnerable to a variety of different threats.
there are many resources to new bird watchers, or "birders," learn to identify different birds. if you are already a seasoned birder, try to find ways to encourage other people, of all ages, to get hooked on birding, and whatever resources you use to identify birds around you, just remember that the most important thing is to have fun!

what effect does the illustration have on the passage?
a.
it the reader imagine how a bird's form relates to its various functions.
b.
it the reader see exactly where certain features are located on birds.
c.
it gives the reader a list of the physical attributes that enable the bird to fly.
d.
it gives the reader an example of a bird that might be found in one's backyard.