What is blue pigeons?

As an AI language model, I don't have access to all data in the internet but to my knowldedge there's no such thing as a blue pigeon. However, there are some pigeon breeds that come in blue-ish shades such as the Blue Bar pigeon, the Blue Check pigeon, and the Blue Pied pigeon. These breeds possess a blue-grey hue in their feathers, caused by a specific pigment expressed in their genetic makeup. Pigeons in general are social birds that have been domesticated for thousands of years and can be found in various shapes, sizes, and colors. They are often kept as pets, used for racing and breeding purposes, or serve as a source of food in some cultures.