In order to drink, most birds need to fill their lower beak with water and tilt their heads back in order for the liquid to enter their throats. Not true for birds in the family Columbidae (pigeons and doves). In the avian world, these birds possess the unique ability to suck liquids into their throat which allows them to drink water without raising their heads.
Adult birds drinking at the middle water feature.
Adult on the left, juvenile on the right at the lower water feature.