You might assume that all Cardinals are a bright red, but that is actually incorrect. Cardinals can also come in other colors such as green and yellow. Even female Northern Cardinals are have duller beaks and faded red bodies. Male Northern Cardinals are the ones most commonly thought of with their bright red feathers and beak. Anyway, these birds reside in most of North America, but concentrated in the United States. They typically eat common bird food such as seeds or small insects and spiders. Its wingspan is about 12 inches and its body length is 9 inches. Northern Cardinals are also very territorial so they try to defend what is considered "their" territory to the best of their ability. They have even been reported to attack their reflections in a mirror if they feel threatened.