family each have been identified as their prey. When attacking these ground-loving birds, which are understandably quite easily spooked and usually react to potential danger by flying off, martial eagles almost always try to take them on the ground much like they do mammalian prey. If the birds take flight, the hunting attempt will fail, although a hunting eagle may try to surprise the same birds again. In Niger, the most numerous prey species is apparently the helmeted guineafowl (Numida meleagris). Other guineafowl such as the vulturine (Acryllium vulturinum) and crested guineafowl (Guttera edouardi) are also readily taken elsewhere. Guineafowl and spurfowl were stated as the most numerous prey for martial eagles in Kruger National Park. In Tsavo East National Park, the red-crested korhaan (Lophotis ruficrista), perhaps the smallest bustard the eagle hunts, is the most numerous prey taken, comprising about 39% of the prey remains. In the Great Rift Valley and Maasai Mara data, the Coqui francolin (Peliperdix coqui) was reportedly the most regularly identified prey and, in separate studies, helmeted guineafowl averaging made up 12% of the foods in Maasai Mara. Medium-sized bustards such as the Hartlaub's bustard (Lissotis hartlaubii) and the karoo korhaan (Eupodotis vigorsii) were oft-taken supplemental prey in Tsavo East and the Cape Province, respectively. Although these are not usually taken in large numbers, martial eagles are one of the main predators of larger bustards. These may include (averaged between the extremely size dimorphic sexes) the Ludwig's bustard (Neotis ludwigii), the Denham's bustard (Neotis denhami) and even the kori bustard (Ardeotis kori), seemingly the heaviest bustard in the world on average at . Attacks on adult male kori bustards, which are certain to be the largest avian prey attacked by martial eagles and are twice as heavy as females, averaging some , can be extremely prolonged. One protracted battle resulted in an injured leg for the eagle and massive, fatal blood loss for the male bustard, which was ultimately scavenged by a jackal by the following morning. Despite its preference for ground-dwelling avian prey, a surprisingly considerable number of water birds may also be attacked. Waterfowl known to be attacked include the South African shelduck (Tadorna cana), yellow-billed duck (Anas undulata), the spur-winged goose (Plectropterus gambensis) (Africa's largest waterfowl species) and especially the peculiar, overly bold and aggressive Egyptian goose (Alopochen aegyptiaca), which is one of the main prey species for martial eagles in Kruger