Blue Bar

The Blue Bar, so named for the iconic bars on the wings, are the original rock dove. The most common of the feral kinds.

Checker

The Checker is so named for the checkered pattern on the wings, which is caused by an overactive Bar Gene. This mutation is man-made, and likely caused by feral pigeons mating with fancy pigeons.

T-Check

The Bar Gene has completely covered the wing, Though the bars are still somewhat visible,

Red Bar Pigeon

Brown pigeons are called Red, and this particular pigeon is descended from fancy breeds. The reason we see so much colour variation in pigeons is because of US! We did this to them. Generations of selected breeding created an enormous amount of variation, but they remained genetically similar enough to interbreed.