The term hawk refers to birds of prey in any of three senses:
The common names of birds in various parts of the world often use hawk in the second sense. For example, in North America, the Buteos are called "hawks".
In February 2005 the Canadian scientist Dr. Louis Lefebvre announced a method of measuring avian IQ in terms of their innovation in feeding habits. Hawks were named among the most intelligent birds based on this scale.
Hawks are believed to have vision as good as 20/2, about eight times more acute than humans with good eyesight. This is because of many photoreceptors in the retina (Up to 1,000,000 per square mm, against 200,000 for humans), a very high number of nerves connecting the receptors to the brain, a second set of eye muscles not found in other animals, and an indented fovea, which magnifies the central part of the visual field.

Accipiter Micronisus Melierax Urotriorchis Erythrotriorchis
In strict use in Europe and Asia, to mean any of the species in the bird sub-family Accipitrinae in the genera Accipiter, Micronisus, Melierax, Urotriorchis, and Megatriorchis. The large and widespread Accipiter genus includes goshawks, sparrowhawks , the Sharp-shinned Hawk and others. They are mainly woodland birds that hunt by sudden dashes from a concealed perch. They usually have long tails and high visual acuity.
More generally, especially in North America, to mean small to medium-sized birds that are members of the Accipitridae, the family which includes the true hawks (Accipiters) and also eagles, kites, harriers, buzzards, and Old World vultures.
Loosely, to mean almost any bird of prey. Species in taxonomic order

Subfamily Accipitrinae

• Genus Accipiter
  
  
  
  • Goshawk, A. gentilis
    Eurasian Sparrowhawk, A. nisus
    Grey-bellied Goshawk, A. poliogaster
    Crested Goshawk, A. trivirgatus
    Sulawesi Goshawk, A. griseiceps
    Red-chested Goshawk, A. toussenelii
    African Goshawk, A. tachiro
    Chinese Goshawk, A. soloensis
    Frances's Sparrowhawk, A. francesii
    Spot-tailed Goshawk, A. trinotatus
    Grey Goshawk, A. novaehollandiae
    Brown Goshawk, A. fasciatus
    Black-mantled Goshawk, A. melanochlamys
    Pied Goshawk, A. albogularis
    Fiji Goshawk, A. rufitorques
    White-bellied Goshawk, A. haplochrous
    Moluccan Goshawk, A. henicogrammus
    Grey-headed Goshawk, A. poliocephalus
    New Britain Goshawk, A. princeps
    Black Goshawk, A. melanoleucus
    Henst's Goshawk, A. henstii
    Meyer's Goshawk, A. meyerianus
    Chestnut-flanked Sparrowhawk, A. castanilius
    Nicobar Sparrowhawk, A. butleri
    Levant Sparrowhawk, A. brevipes
    Slaty-mantled Sparrowhawk, A. luteoschistaceus
    Imitator Sparrowhawk, A. imitator
    Red-thighed Sparrowhawk, A. erythropus
    Little Sparrowhawk, A. minullus
    Japanese Sparrowhawk, A. gularis
    Small Sparrowhawk, A. nanus
    Rufous-necked Sparrowhawk, A. erythrauchen
    Collared Sparrowhawk, A. cirrocephalus
    New Britain Sparrowhawk, A. brachyurus
    Vinous-breasted Sparrowhawk, A. rhodogaster
    Madagascar Sparrowhawk, A. madagascariensis
    Ovampo Sparrowhawk, A. ovampensis
    Rufous-chested Sparrowhawk, A. rufiventris
    Shikra, A. badius
    Tiny Hawk, A. superciliosus
    Semicollared Hawk, A. collaris
    Sharp-shinned Hawk, A. striatus
    White-breasted Hawk, A. chionogaster
    Plain-breasted Hawk, A. ventralis
    Rufous-thighed Hawk, A. erythronemius
    Cooper's Hawk, A. cooperii
    Gundlach's Hawk, A. gundlachi
    Bicoloured Hawk, A. bicolor
    Besra, A. virgatus
    Genus Micronisus
    
    
    
    • Gabar Goshawk, M. gabar
      Genus Melierax
      
      
      
      • Dark Chanting Goshawk, M. metabates
        Eastern Chanting Goshawk, M. poliopterus
        Pale Chanting Goshawk, M. canorus
        Genus Urotriorchis
        
        
        
        • Long-tailed Hawk, U. macrourus
          Genus Erythrotriorchis
          
          
          
          • Red Goshawk, E. radiatus
            Chestnut-shouldered Goshawk, E. buergersi
            Genus Megatriorchis
            
            
            
            • Doria's Goshawk, Megatriorchis doriae
              Subfamily Buteoninae
              
              
              
              • Genus Parabuteo
                
                
                
                • Harris's Hawk, P. unicinctus
                  Genus Buteogallus
                  
                  
                  
                  • Common Black Hawk, Buteogallus anthracinus
                    Mangrove Black Hawk, Buteogallus subtilis
                    Great Black Hawk, Buteogallus urubitinga
                    Rufous Crab-hawk, Buteogallus aequinoctialis
                    Savanna Hawk, Buteogallus meridionalis
                    Genus Busarellus
                    
                    
                    
                    • Black-collared Hawk, Busarellus nigricollis
                      Genus Leucopternis
                      
                      
                      
                      • Plumbeous Hawk, Leucopternis plumbea
                        Slate-coloured Hawk, Leucopternis schistacea
                        Barred Hawk, Leucopternis princeps
                        Black-faced Hawk, Leucopternis melanops
                        White-browed Hawk, Leucopternis kuhli
                        White-necked Hawk, Leucopternis lacernulata
                        Semiplumbeous Hawk, Leucopternis semiplumbea
                        White Hawk, Leucopternis albicollis
                        Grey-backed Hawk, Leucopternis occidentalis
                        Mantled Hawk, Leucopternis polionota