This group contains three families ; Alcedinidae ( river kingfishers ) , Halcyonidae ( tree kingfishers ) , and Cerylidae ( water kingfishers ) .
The group is treated either as a single family , Alcedinidae , or as a suborder Alcedines containing three families , Alcedinidae ( river kingfishers ) , Halcyonidae ( tree kingfishers ) , and Cerylidae ( water kingfishers ) .