Just as you know your friends by their voices or physical characteristics, the experienced birder knows a species of bird by a glimpse of its tail or the shape of its bill.  These particular clues are called field marks.  Other common field marks include size, shape, habitat, voice, and behavior.  The best way to become familiar with field marks is to start watching the birds in your front yard or local park.  Spend time observing the bird while it is in sight, then go to the field guide to identify it.  Note as many field marks as time will allow.  Once you have made note of the obvious field marks, you can easily refer to a field guide to identify the bird.  A notebook for recording field marks and a pair of binoculars will help with identification.  

The Main Field Marks to Note Are:

• Size:  Try to get an idea of the size of the bird.  A familiar bird such as the American robin or a set object nearby, can be helpful comparisons to judge the relative size. 

• Shape:  What shape is the body, tail, bill and wings?  Note relative size, width, length and thickness to name a few.  For example, is the bill cone shaped or pointy, larger or smaller than a pencil tip?

• Plumage:  or feathers.  Note the overall colors and patterns of the  bird's feathers (i.e.,  crescents, bars, and spots) particularly on the head and wings.  

• Habitat:  Just as ducks prefer water and robins prefer grassy lawns, other birds can typically be found in a certain habitat.  Note the type of habitat the bird was seen in.  Is it on the ground, high in the tree canopy, or on a fence post?  This clue is typically  affected by the time of year and abundance of preferred habitat.

• Behavior:  How does the bird feed?  Does it cling to the side or a tree as a woodpecker or dabble in a lake as a duck?  How does the bird fly?  Does it undulate up and down like a woodpecker or spiral up in a thermal like a raptor?  Is the bird approachable or secretive? 

• Voice:  For an added identification challenge, try learning the songs and calls of birds.  This is particularly helpful with nocturnal birds, birds that are very similar in appearance such as flycatchers, or those that prefer dense cover such as thickets.  

Try to narrow your options to waterbird (i.e., ducks, geese, gulls, shorebirds and wading birds located in the first half of most field guides) vs. landbird.  You can further narrow your field by using the home range map, located in most field guides.  These maps will give you a general idea of location and seasonality.  A word of caution, though, birds have a disconcerting habit of being in the wrong place at the wrong time, especially during migration.  

• When to look:  Generally, most birds are active in the early morning hours until 9am. Seasonally, birds are most visible during spring when they are setting up and defending territories or courting mates.  

• How to spot:  Lock your eyes onto the bird or birds and bring the binoculars up to your eyes without moving your head.  If you cannot see the bird through your binos, try moving the binos in the pattern of a cross from your starting point in case it has shifted position.  A more time consuming, yet easier method is by using a fixed reference point such as a large red barn in the background or a broken top tree.  Note where your bird is in relation to that fixed point without your binoculars and relocate the bird with the binoculars.  

• How to point out your bird to others:  The best way to show another person where you are looking is to use the clock  method.  This method divides the field of view (i.e., a tree, the sky, distant mountains, etc.) into a clock face.  Generally, 12 o'clock is the top of your reference point with 3 and 9 o'clock to the right and left respectively.  This method works great as long as everyone is on the same page.  To be sure everyone knows what your reference points are, try describing the scene from general to specific such as:  "I've got a perched warbler, in the alder tree, at 9 o'clock."  or "I've got a raptor in the sky at 11 o'clock, just above that contrail."  This method works well if you are birding from a fixed location and everyone is looking in a fixed direction such as at most hawk watch sites.