I was trying to find some information on classification of these large carnivorous birds. I Came across the following info. For the benefit of relatively dumb people like me, I'll start from the beginning ... :) -

All living things are divided into 5 Kingdoms

• Kingdom Planta = Plants

  
  




• Kingdom Fungi = Fungi

  
  




• Kingdom Animalia = Animals

  
  




• Kingdom Protista = very small things called Protoctista

  
  




• Kingdom Monera = even smaller things called Bacteria

  
  

Note: Viruses are not included in any of the above.

The living members of the kingdom Animalia are divided into approximately 37 smaller groups called phyla (singular phylum).

One of which, the Chordata is of particular interest to us. This phylum contains all the animals which have (at some stage in their lives) a notochord. This is a stiffened but flexible rod that runs along the animals back between its gut and its central nervous system. The Phylum Chordata is divided into 3 subphyla:-

1. Urochordata (Sea Squirts and their allies

   
   




2. Cephalochordata (Brachiostoma, a small fish like creatures once known as Amphioxus)

   
   




3. Vertebrata (birds, fish, frogs, mammals, snakes etc.)

   
   

The subphylum Vertebrata contains 7 smaller groups called Classes, these are:

• Class Agnatha = Jawless vertebrates

  
  




• Class Elasmobranchiomorphi = Cartiliginous fishes (Sharks and Rays)

  
  




• Class Teleostomi = Bony fishes (Salmon, Trout, Carp etc)

  
  




• Class Amphibia = Frogs and Newts

  
  




• Class Reptilia = Snakes and Lizards

  
  




• Class Aves = Birds

  
  




• Class Mammalia = Mammals (Cows, Dogs, People etc)

  
  

Now the Aves or Birds are divided into 23 even smaller, though still pretty large groups called orders.

The order Ciconiiformes, contains the following types of birds:

Albatross, Caracaras, Eagles, Falcons, Flamingos, Gulls, Hawks, Herons, Kites, Pelecans, Penguins, Storks, and Vultures.

However, Accipitriformes is an order that has been proposed to include most of the diurnal birds of prey: hawks, eagles, vultures, and many others, about 225 species in all. For a long time, the majority view has been to include them with the falcons in the Falconiformes, but some authorities have recognized the need for a separate Accipitriformes order.

A recent DNA study has indicated that falcons are not closely related to the Accipitriformes but are instead related to parrots and passerines (a different order altogether).

The DNA-based proposal and the IOC (International Ornithological Congress) classification, include the New World vultures in the Accipitriformes. The SACC (South American Classification Committee) classifies the New World vultures as a separate order. The placement of these birds has been unclear since the early 1990s.

So the order Accipitriformes, contains the following families:

• Accipitridae (buzzards, eagles, harriers, hawks, kites, Old World vultures)

  
  




• Cathartidae (New World vultures including condors)

  
  




• Pandionidae (Osprey)

  
  




• Sagittariidae (Secretary Bird)