Keys are widely used to identify plants and insects. They are used less often with birds because of the variations in plumage based on time of year, race, age and sex. Nevertheless, when used with caution they can be helpful.
Use the two keys (sparrows with a clear breast and sparrows with a streaked breast) to assist your identification process. It will not work with every sparrow but will often point you in the right direction and the process of using the key will help you develop your identification skills. Remember that poor lighting conditions and plumage variations may affect your ability to see the field marks used in the key.
The keys work in three steps, using the following criteria:
- Is the breast streaked or clear?
- Does the bird have wing bars ?
- Does the sparrow have an eye ring?
The key is for adult birds.
Keep in mind that wing bars and eye rings may be more or less visible depending on the time of year, age of the bird, lighting and distance from the observer.
When observing a sparrow that you do not recognize, start by making a note (mental or, even better, written) of all the distinguishing characteristics you can see, including the marks in our key. Many birders find that if they say (quietly when observing the bird) what they see, they can remember it better.
After selecting either streaked or un-streaked, work the key from the top to the bottom.
You may need to work back and forth (up and down, actually). If you think the sparrow in question has a wing bar but the descriptions of the birds under this category clearly do not fit, then move down to the “Faint or No Wing Bar” list of birds and try again. (Feather wear or lighting could cause the bird to look like it has a wing bar.)
You’ll soon get the hang of working the key back and forth and coming up with the best fit.
Unfortunately, often you can see only one side of a bird and some field marks may not be visible. The key may not help in this situation or you may still be able to jump to a section (like clear breast and eye ring) even if you could not see the wings.
Note: Juvenile sparrows often have streaked breasts, even if they have a clear breast in adult plumage. Five-striped, Rufous-winged and Botteri’s sparrow are not in the key because of their very limited range. Juncos and Lark Bunting are also not included in the key.
We do not expect the keys to help you identify every sparrow you see. The process of working through the keys will raise your awareness of, and attention to, key marks that separate the different species. Experience in the field is the key to good sparrow identification.