Take this 1st year Female American Redstart for example. When you have trouble identifying a bird, it is a good idea to try and find something on the bird that is rather distinctive. It can be anything: an eye ring, a faint streak on the belly, bill color, bill length, or leg color. Anything that would help while looking at it in the field guide. Look at the American Redstart in this picture. What are the field marks? Let's see, where the yellow is located on the bird, the amount of yellow underneath and how bright it is, how the tail is positioned, and the white eye ring. These are simple field marks of the Redstart. But some birds require very descriptive field marks and some don't even have any differences at all. For example the Alder and Willow Flycatcher. There is not a way to tell which species it is until it vocalizes. ( Vocalization, key factor in birding.) The field marks of a bird is what makes it unique. Thanks for reading everybody and happy birding!
- John Mark Simmons
Photo by John Mark Simmons