With their bright red plumage, male Northern Cardinals (Cardinalis cardinalis) are quite conspicuous and very easy to spot, which not coincidentally, is often how they like it. Male Northern Cardinals are aggressively territorial, and they will not tolerate the presence of other male Northern Cardinals in their territory. Their bright color is an aggressive signal, and the brighter red the male, the more desirable the territory he is able to acquire and defend, and thus the greater his and his mate's reproductive success.
While the red color of male Northern Cardinals is certainly not intended as camouflage, the male Northern Cardinal that has claimed my yard has managed to find a well-camouflaged lookout perch, Ocotillo (Fouquieria splendens) canes tipped with red flowers.
The Northern Cardinals like to visit my bird feeders late in the day, and the male usually perches in a nearby Ocotillo for a quick look around before venturing down to the feeders. When observed from a fair distance, he can be surprisingly difficult to see amidst the red flowers.
Since Ocotillos mainly bloom in the spring, this male Northern Cardinal will eventually lose his camouflage and return to being a solitary splash of red in the dull greens and browns of the desert. There are other red birds here in Tucson, but none are so common and widespread as male Northern Cardinals.
For more examples of colorful camouflage, check out these photos of Abbott Handerson Thayer's animal camouflage paintings on the web: