How To Identify Birds (5 Main Factors to Consider)

This article contains affiliate links. If you make a purchase after clicking a link, we get a small commission at no cost to you.

All of us bird watchers at one time or another have found ourselves squinting at a bird saying “what is that?” With the hundreds of bird species found in the U.S. alone, there are a lot to choose from. Being good at identifying birds is a skill that, like any other, you gain with patience and practice. In this article we are going to discuss how to identify birds by discussing all the key things to look for, and tips on how to get started.

Great gift idea for the bird lover: Birds stained glass sun-catcher! 50% OFF WITH FREE US SHIPPING - BUY NOW ON ETSY

How to identify birds in your backyard

Birders skilled in identification aren’t just looking at color or stripe patterns. Those things are important, but there are many other things to take into consideration to narrow down your choices. Let’s look at the five main categories of information we want to collect about a bird in order to make an ID.

Five Bird Identification Categories

  1. Location & Habitat
  2. Color
  3. Shape & Size
  4. Patterns & Markings
  5. Movement & Behaviors

Let’s start with one that is simple, but often overlooked.

1. Location & Habitat

Range

Before you drive yourself crazy looking at the minute details of the bird, start broadly by considering the state you are in, and what time of year it is. This is where having a range map is so helpful. You can find them online at sites like Cornell’s All About Birds, or in most field guides. You can rule out a lot of birds by knowing when and where they are likely to be present.

For example, unless you are very experienced, a Carolina chickadee looks identical to a Black-capped chickadee. But if you are in Massachusetts you don’t need to wonder which you are seeing because these chickadees have very specific ranges. If you live in New England it’s a Black-capped and if you’re in the southeast it’s a Carolina. Many similar looking birds have their own ranges in different parts of the country and rarely, or never, meet. That is a quick way to rule something out. 

Time of year you see the bird matters too, since many birds migrate. Range maps will tell you if a bird is located in your state all year, or if it only shows up during spring-summer or fall-winter. 

Habitat

Once you’ve ruled out birds that would be unlikely for your area, think about the immediate habitat you saw them in. Open field? Swamp? At the beach? In a dense forest? If you are convinced the bird you saw was a type of tern, but you are nowhere near the ocean, you’re probably barking up the wrong tree.

Habitat can be especially helpful when you think you’ve narrowed it down to a species, like sparrows, but there are many possible sparrows in your area and they all look similar. A field guide will help point out the specific habitats each bird is most likely to be found in. 

2. Color

Color is perhaps the most obvious thing we think of when trying to identify a bird. For most of us it is the first thing our brain catalogs. Full body bright colors are actually in the minority for U.S. birds, so it can really make identification easy if the bird is all red or all blue.  

But smaller splashes of color can be an excellent way to differentiate birds. For example in backyards, female House Finches are often confused with Pine Siskins. While not the only way to tell them apart, one of the quickest is the small streak of yellow siskins have on the edge of their wings and tail. 

Much of the time, you will be working with shades of gray or brown. In that case, notice any little nuances you can.  Try to identify hues, for example was it a light tan colored brown or a rich chestnut brown? Was the shade of brown different on one part of the body than the others? And if all you can see is light or dark, note that too. Which areas of the body were darkly colored and which were lighter? 

The reddish brown tail, that was a distinctly different color than the rest of the back, helped me identify this Hermit thrush over other similar looking thrushes.

3. Shape & Size

If I were to describe a bird that had a brown back and a white chest with brown streaks, that could fit anything from a sparrow to a hawk. This illustrates the importance of size and shape.

Size

Size can really help you narrow down your category. If your mystery bird is close to other birds you know, then getting an idea of their size is simple. However if the mystery bird is on its own, one trick is to think of a bird that you see often and know well. Compare the size of the mystery bird to a bird who’s size you are familiar with, for example “bigger than a robin” or “smaller than a cardinal”. 

Shape

Practice thinking about the silhouette of the birds you are seeing. Notice the shape of the bill, the tail, its head, body and wings. The example below shows the different shapes of some common birds, I bet many of you can identify which is an owl, a pelican, a heron, a duck and an eagle. 

It's never too late to start feeding hummingbirds. Here's a quick list of things you'll need to get you started!

  1. Hummingbird feeder poles
  2. 12oz hummingbird feeders
  3. Ant moats (optional)
  4. Make your hummingbird nectar at home
Fill your feeders with the nectar, and put them out! Hummingbirds can start showing up anywhere between late February and early May, depending on where you live.
Nature Vectors by Vecteezy

Birds within the same family tend to have the same shape. The better you get at recognizing them, the quicker you will be able to narrow things down. 

By putting size and shape together you can get even more information. For example, how long is the birds beak in relation to its head? The similar looking Downy and Hairy woodpeckers are often told apart by their beak length, with the Hairy’s beak being much longer in relation to the width of its head. You can use this trick with other thing such as tail length or wing span. 

4. Patterns & Markings

The devil’s in the details. Sometimes patterns are striking and obvious, but often it’s the subtle differences that can clinch an identification. These are called field markings, and the illustration below points out the different areas of a bird where you can find specific markings and coloration. Make special note of anything that sticks out, such as a colored cheek patch or wingbars.

Example of common field marks to note when IDing a bird. (Figure from the Trinidad & tobago bird status & distribution committee; ttbsdc.ttfnc.org)

It may be helpful at first to practice noticing common feather patterns of different groups of birds. For example, most woodpeckers have a black back with white stripes or spots, while sparrows are streaked with browns and grays, and members of the thrush family often have plain brown backs with white chests dotted with brown spots. By observation and flipping through a field guide, you can learn the characteristic appearance of different groups of birds. 

5. Movement & Behavior

Experienced bird watchers can often identify a bird by how it has positioned itself and its “personality” or behavior. Getting a feeling for the attitude of each species can really help to narrow things down after noting size, shape and other factors. 

Does the bird sit calmly or is it always moving about nervously?  Does it hold it’s body up confidently and upright or is it always crouching down or making its body more horizontal? Will it perch in the open and take in its surroundings or is it always hiding in the bushes? These subtle attitudes of different bird species are learned over time by observation.

How Do They Forage?

Also pay attention to what the bird is doing, and where. Especially when it comes to foraging. Staying hidden in bushes and shrubs? Digging around on the ground? Flying back and forth over a field? Zipping vertically up and down a tree? While swallows will dip and dive over large open areas to catch insects in the air, vireos prefer to do their foraging amongst the leaves at the tops of trees, and towhees will scratch around through the leaf litter on the ground to find their bugs. 

Example ID

Below is an example of using the methods discussed above to identify a bird found at your feeder.


Additional Tips & Resources

Below are a few additional tips to keep in mind when trying to identify a bird, and some great resources to help you out. 

Sexual Dimorphism

This term refers to different coloration and patterns on the male of a species versus the female. The females of birds such as cardinals, blackbirds, finches and orioles can look quite different than the males. Typically for songbirds and ducks, the males will be more brightly colored while the female remains dull or brown. If you see something new at the feeder and can’t identify it, try considering the birds you usually see and looking up their female counterparts.  

Sometimes birds will also become duller in the winter, then molt into brighter colors during mating season. The goldfinch is notorious for this, becoming a washed out olive color in the winter to the point many people think a new bird has shown up at the feeder. 

Juveniles

Just because a bird has reached its adult size doesn’t mean it has its adult plumage. Juveniles can sometimes take up to a year to get their full adult coloring and patterns. Use all the ID tips above to get your best guess, and most field guides should at least have a description, if not an illustration, for birds with tricky juvenile plumage.

Field Guides

I can’t stress how important it is to have a field guide if you are interested in identifying birds. I’m partial to the Peterson’s guides, which are divided up between Eastern & Central North America and Western North America. By sticking to a certain region it really packs in the most information about the birds in your specific area of the country. 

However there are a ton on the market and whichever one is the easiest for you to use, is the right one for you. Also, it’s not like birds change every year and you need the most up-to-date version of a guide. I’ve found most used bookstores have a couple field guides for just a few dollars, and the information in them is just as good.

I personally like having a physical book because it really aids in learning the shapes, silhouettes and coloring of birds in certain families. When you can compare a whole page of flycatchers against a whole page of vireos, you can really start to visually learn those little differences that set them apart. 

Online Resources

The Cornell Lab of Ornithology has a great app called Merlin that can help you ID birds on the go right on your phone. It takes all the categories we discussed in this article and asks you a series of questions about the bird you saw such as, what color it was and how large it was. It then presents you a selection of birds that fit your description that would commonly be found at your location, on the date you saw the bird. It’s a great tool and even if it doesn’t find your bird for you, it helps you get used to thinking about those identifying factors. 

About Melanie

Melanie has been a birding hobbyist for years and loves feeding and photographing birds of all types.