What are baby pigeons commonly called?

Baby pigeons are commonly referred to as "squabs." This term is specific to young pigeons and derives from the Old French word "esquab," which refers to a young bird. Squabs are typically about 4 weeks old when they fledge, or leave the nest for the first time.

The other terms listed, while they may refer to young birds in general, are not specific to pigeons. "Chicks" are often used for young chickens and other birds, "peeps" can refer to the sounds that chicks make or informally refer to small birds in general, and "hatchlings" typically describe newly hatched birds of various species, including but not limited to pigeons. However, when it comes to baby pigeons specifically, "squabs" is the correct term and is widely recognized in both ornithological and everyday language.