Cryptic coloration—the ability of an animal to blend in with its surroundings—has always fascinated me. Cryptic coloration is the reason there are so many brown, striped sparrows. It’s why female ducks and other species lack the bright plumage of their mates. It’s why birds show regional differences. And it’s why I almost missed seeing the Long-billed Curlew shown here.

If you’d been birding with me this past winter, you might have heard me mumble…

• “I think that’s a Hairy Woodpecker. It looks like a Hairy. But, it’s so dark!”

• “Is that a Song Sparrow? It has the right stripes and the central dot; it must be a Song Sparrow. But, it’s so dark!”

• “Wow, look at that Red-tailed Hawk. I know it’s wet, what with all this rain, but the feathers seem, I dunno, so dark!”

This is what happens when a Colorado birder goes birding in the Pacific Northwest. To a large extent, we have the same familiar birds. They act the same, they’re the same size and have the same markings,  but there’s often a conspicuous difference. The birds are so—dark!

I ran into the opposite effect when birding southern Arizona. There, the birds tended to be lighter than I was used to.

It’s pretty obvious what’s going on. In areas with intense sunlight, light-colored sand, few leaves and fewer shadows, lighter colored birds blend in. When that sharpie comes a-hunting, birds with dark feathers end up as dinner while the light ones are overlooked. Similarly, in the northwest, the skies are cloudy much of the time. The birds lurk in the dark depths of firs, hemlocks, and other dense evergreens. There, the lighter birds stand out, while the dark ones can hide. So, most of the birds are darker.

This makes sense, but not all birds are camouflaged. What about brilliant birds such as tanagers, lorikeets, and birds of paradise?

It’s all about sex. Bright colors indicate health and strength, and a female bird wants a fit and vigorous male to help her defend her nest, provide food for their family, or, at a minimum, to pass his successful genes to her offspring. A male’s intense colors can also intimidate a potential competitor, basically telling him not to bother. As a result we have crayon-colored macaws, scarlet tanagers, and iridescent hummingbirds.

Even with the most outrageous color combinations, there is a limit. Male birds walk a tightrope between hiding from their enemies and successfully breeding. At some point, the fancy plumes and bright colors are so disadvantageous, they balance with the need for visibility and the ability to impress.

Then again, what appears to be a bright bird to us humans may actually not be all that conspicuous. Most trees have a few yellow leaves, even in the spring and summer months. We use yellow for caution lights and danger signs, but a Yellow Warbler in a cottonwood blends in pretty well with the leaves. These yellow “leaves” just happen to hop around pecking up bugs.

Bright colors can act as camouflage in other ways. Consider “color blocked” birds—those that have different colors on different parts of their body. Chickadees (right), parrots, and orioles come to mind. Those different colors break up the bird-shaped outline of the body, fooling predators.

Bright colors may also serve to send a warning. A junco fleeing a threat will flash its white out tail feathers, warning the rest of the flock to run away too. Other birds use red to signal danger.

Blending into your surroundings is clearly a good survival strategy, but it makes birding much more challenging. How many of us have photographed an owl, only to get home and realize there are two owls in the picture? Or had someone pointing right at that ptarmigan (left)—only you can’t see it? Then there’s the birding friend who took a photo of a coot, finally downloaded it onto his computer, and discovered a Least Bittern in the background—in Colorado! A primary reason some of my friends are such terrific birders is that they’re able to pick out even well-camouflaged birds—the ones I miss.