Identifying Birds in the Field: The Basics

ID that bird! exercise below.

Birding Tip #3: Get to know your birding field guide(s).  By studying your guide, you'll be able to recognize birds easier and find them faster in your guide while in the field.  You'll be surprised when you can identify a bird in the field that you haven't seen before in person but you've seen it in your guide!

The Sibley Field Guide to Birds by David Sibley is a very concise field guide and it's easy to use.  One of my favorite features of this guide is the variety of images for each species.  Since birds can trick you by changing plumage from winter to spring and the variance between males and females, it's handy to have a guide that shows you the difference.  The images are very thorough and they show you important field marks that make it easier to identify individual species.  We will look at field markers in a moment. 
 
In this guide, each family of birds has a summary page that introduces the family with some background information, separates the family into genera, provides an image of each species and gives the page number.  This page makes it easier to navigate the different families (left).

Once you get to the species you're interested in, the guide tells you some background about that species, such as whether the species is common or not, where it can be found, a physical description and the typical vocalization (right).  You will also have a range map for that species showing it's range during winter, summer, where it occurs year-round, during migration and where it is rarely seen.  In this example, you can see the variety of images of the dark-eyed junco, the Oregon and pink-sided varieties. 

I like this guide because it shows you almost every variation of that species.  It shows male and female, juvenile and any other commonly seen variations, such as the pale adult, seen below.  In the photo below you will see the dark head of the dark-eyed junco, Oregon variety.  This feature is a field mark.

photo by Ted Schroeder

So, what's a field mark?   A field mark is a visually distinct feature that distinguishes a certain species or even a family. To the right is a slate-colored variety of the dark-eyed junco.  This picture also shows another very distinctive field mark used to identify dark-eyed juncos.  Can you see it?  The white tail bars on each side of the tail occur in all junco varieties and are very apparent while in flight.




When birding, there are a few, very basic questions that should run through your head the second you see a bird.

1. How big is it relative to other birds?  For example, is it bigger or small than a robin?  If it's smaller it may be a sparrow or a finch.  If it's about the same size it may be a thrush or grosbeak.  If it's bigger than it may be a jay or a crow.  This may seem arbitrary, but it's a very simple process of elimination that you can do rather quickly.
2. Where am I?  This may seem like a silly question, but it's important to know where you are.  Are you on the beach or deep in an old growth forest?  This will make a big difference in the birds you're going to see.  For example, you know if you're standing in a forest far from the ocean you're unlikely to be searching the waterfowl section.  On a broader scale, you should compare where you are on a national scale (or within a state) to the range map for the particular bird (once you have identified it).  
3. Are there any field marks?  Does the bird have a definitive feature that allows you to quickly narrow down the search?  The most common field maks are going to be color pattern.  Let's consider two relatively common species, the golden-crowned sparrow and the white-crowned sparrow. 

Golden-crowned sparrow, photo by Jeffrey Rich

White-crowned sparrow, photo by Linda Williams

 Apart from size (the golden-crowned sparrow is slightly larger) these two birds look relatively similar.  So can you identify the field mark used to distinguish these two species?  (Hint: the names give it away!).   The golden-crowned has a yellow fore-crown (the rest is white) and the white-crowned has a completely white crown.  Can you see any other differences in these two species?  Another noticeable feature is also on the head.  The white-crowned sparrow has a white eye stripe while the golden-crowned has a black cap.  I also think the golden-crowned sparrow looks tired, because it looks like it has bags under it's eyes.

Now that we have learned the basics on identifying birds, let's do an exercise.  Feel free to grab a field guide!

Below is a photo I took of a bird in my backyard.  Let's try to identify it using the questions we discussed.

Photo by Kelly Wohlwend (Author)

Ask yourself question #1, how big is this bird?  I'll help you out here, this bird is smaller than a robin.  

What about question #2, where am I?  Here's another clue, I live in a forested suburb in Western Washington at the base of the Cascade Mountain Range foothills near sea level.  

Lastly, question #3, are there any field marks?  Look for distinctive features that stand out.  How about that long tail that seems to stand upright?  It may be hard to see in this picture but do you see a white eye stripe above the eye?  Also take note of the color, what color is the bird's body and chest?  

If you have looked through a birding field guide enough you may know that this bird is a wren.  How did I know?  Wrens have a very telltale feature that makes them stand out, their tail.  Wrens generally keep their tails upright.  Some wrens, such as the pacific wren have short tails but they all stand up straight, sometimes at a 90 degree angle to the body. 

Marsh wren, photo by Marie Read

So now that you know this bird is a wren, have you figured out which one?  If you have pulled out your field guide (or are just a more experienced birder!) you will see that more than one wren has a long, cocked tail and a white eyebrow.  That is why the area you are birding in is important.  You may mistake this bird for a marsh wren, however, marsh wrens are found where their name implies, in wetland habitats (right). 

The mystery bird may also be confused with the house wren, however, the house wren has a less distinctive eyebrow and prominent, black stripes on the wing feathers.

So given all this, what bird did I photograph in my backyard?


(Answer below...no peeking!)









The answer is...a bewick's wren!

I hope you had fun and learned some helpful tools that will help you Be Your Best Birder! 


References:


Sibley, Allen D.  2003.  The Sibley Field Guide to Birds of Western North America.  New York: Alfred A. Knopf.  471 pp.  

The Cornell Lab of Ornithology, 2011, http://www.allaboutbirds.org

*book images taken from  Sibley, Allen D.  2003.  The Sibley Field Guide to Birds of Western North America.  New York: Alfred A. Knopf.  471 pp.