 The Pteroclididae was formerly included in the Galliformes due to the similarities the family shares with the true grouse. However, it was later discovered that these similarities are superficial and a result of convergent evolution. Sandgrouse were later placed near the Columbiformes largely due to their reported ability to drink by the "sucking" or "pumping" action of peristalsis of the esophagus, an unusual characteristic. More recently, it has been reported that they cannot suck up water in this way, and they are now treated separately in the order Pteroclidiformes. They have been considered near passerine birds and are considered by some to be closer to the shorebirds.
