Purple birds are not necessarily rare but are not as common as birds with other plumage colors. The color purple in birds is often caused by the presence of specific pigments called carotenoids and melanins, which are less common in the feather structure of birds than other pigments like red, yellow, and brown. As a result, birds with purple plumage are often more unusual and striking in appearance. Additionally, some species of birds with purple plumage may have limited distributions, making them rarer in certain areas. For example, the Purple Gallinule is relatively common in wetlands in the southeastern United States, Mexico, Central America, and the Caribbean. Still, it is considered rare in other parts of the world. While purple birds may not be as common as other birds, they are not necessarily rare, and several species can be found in different parts of the world. However, their striking appearance and limited distribution can sometimes make them highly sought after by birdwatchers and nature enthusiasts.