which can in some species be nearly all white, but even where the differences are subtle between adults and immatures, usually some physical differences are noticeable such as white wing patches in traditional Aquila species, to visually distinguish young from adults. Many species have a notable head-crest, such as Nisaetus and most Spizaetus, with the feature being most extreme in the long-crested eagle (Lophaetus occipitalis). Like most accipitrids, they have large powerful hooked beaks for tearing flesh from their prey, strong legs and powerful talons. Compared to other large raptors, the feet and talons of booted eagle species are often particularly large and powerful relative to their size. The most extreme example seems to be the crowned eagle, which has a hallux-claw (or rear talon) of around about the same sized hallux-claw as the Philippine eagle (Pithecophaga jefferyi) (not part of the Aquilinae), which weighs on average nearly twice as much. The booted eagles also have extremely keen eyesight to enable them to spot potential prey from a distance. Life histories and range Booted eagles are varying in their habitats and habits, being found on every continent inhabited by accipitrids, which includes all continents with the exception of Antarctica. They may inhabit nearly all of the world's terrestrial habitats, with the majority of species being largely forest dwelling, but several preferring all kinds of open habitat from steppe to prairie to tundra as well as most rocky or mountainous areas. By far the widest ranging species of booted eagle is the golden eagle, which is distributed in most of North America (where it is the only species of the subfamily north of Mexico) and much of Eurasia including a majority of Europe, often along most mountainous terrains therein but also other land-based habitats with typically remote semi-open or hilly hunting grounds accessible. So-called "hawk-eagles" are forest dwelling booted eagle types largely represented by Spizaetus (in the neotropics) and Nisaetus (in Asia). Despite many similar features in the two main hawk-eagle genera, they apparently evolved separately for some time and are not closely related. The peak diversity for Aquilinae are in Africa, where nearly half of extant species are known to dwell at least seasonally, exploiting a diversity of different hunting styles, habitats, nesting habits and general body forms. All booted eagle species are opportunistic predators which prey mostly on small vertebrates, often subsisting on a wide range of mammals, birds,